A Crowned Eagle attending a chick

Results from the project may have implications for raptor conservation in the wider region.  For example, hunters from the village of Batoke, bordering the Mount Cameroon National Park, openly admitted to hunting crowned eagles (Stephanoaetus coronatus).  They also suggested that encounters with crowned eagles had reduced during their career (as long as 15 years) and they now expected to encounter only one eagle per annum.  As in the Ebo forest, hunters here are familiar with crowned eagle vocalisations and with the techniques used to mimic crowned eagle calls.  This is worrying and suggests that the technique is used throughout Cameroon’s forest belt, as Mount Cameroon is distant from the Ebo forest in both cultural and logistical terms.  Although crowned eagles are likely to be among the most vulnerable species because of their low reproduction rate, more common species such as palm-nut vultures (Gypohierax angolensis) and gymnogenes (Polyboroides typus) are also hunted regularly (see photo).  It appears that any medium to large raptor is targeted when the opportunity arises and it is essential that this off take is measured quantitatively so that sustainability can be assessed.

Mammal research is also developing in the Ebo forest and intensive transect surveys are now being carried out.  Several field assistants received raptor recognition training in June 2011 and now record crowned eagle vocalisations when walking transects.  This valuable data will allow us to begin monitoring crowned eagle populations in the Ebo forest and to detect changes over time.

The single crowned eagle nest located in 2009 was monitored throughout 2010 but remained unattended and had disappeared by July 2011.  This was disappointing but we did observe a pair of crowned eagles displaying above our base camp (Bekob) in July 2011 and are probably nesting near by. Hunting has decreased generally in the Bekob area as a result of the EFRP’s presence and this may have a positive affect on raptors in the local vicinity, as has been observed with primates.

A persecuted Harrier Hawk (gymogene)

We hope to further train local field assistants to identify raptors in the field by both site and sound and increase monitoring of other species in the future. The Ebo forest is undergoing the transition to National Park status and although the process is slow, this will undoubtedly be positive for raptors and their conservation in Cameroon.

More information about the Ebo Forest Research in Cameroon can be found at their website.

Andrew Jenkins is one of the most prominent raptor biologists in South Africa and has been studying Peregrine Falcons on the Cape Peninsula for more than twenty years. His interest in falcons also extends to other species and he published the first confirmed records of the presence of Taita Falcon in South Africa in the 1990’s and has been involved in the surveying of this population of the species for many years. Andrew established a raptor research programme (Western Cape Raptor Research Programme) at the FitzPatrick Institute, University of Cape Town and has been instrumental in setting up numerous long-running projects. These include population studies on the Rock Kestrel, and Black Sparrowhawk, pesticide studies of African Fish Eagles, behavioural ecology studies of Black Harriers and colour marking studies of Black Eagle. He is also one of the foremost experts in terms of the impact of energy infrastructure on raptors and other birds and currently consults extensively in this regard, in particular with regard to the many wind-power developments planned in southern Africa. Andrew is also the author of many scientific and popular publications and was this year honoured with the Endangered Wildlife Trust Birds of Prey Programme’s Raptor Conservationist of the Year Award.

André Botha

Taita Falcon perched, © Alan Kemp

1) What is known about the status of the Taita Falcon across Africa? How many birds are there?

The Taita Falcon occurs down the eastern half of Africa, as far west as the Rift Valley, as far north as southern Ethiopia, and as far south as north-eastern South Africa. This might seem like quite an extensive range, but it is very patchily distributed within this area, in a way that is not presently well understood. Like the Peregrine, it seems to go for habitats that particularly favour it’s cliff-nesting and bird hunting habits – high cliffs in bird-rich areas – but it seems to be much more picky than its bigger cousin. The net result is that its global population is manifested as small, scattered pockets of localised ‘abundance’, sometimes comprising only 1-2 breeding pairs, separated by 100s, even 1000s of kilometers of apparently unsuitable habitat. This impression of patchiness in its distribution may be exaggerated by problems with detecting this small, fast-flying but relatively sedentary species in habitats that are difficult to access, and it has probably been overlooked in some of the less explored areas of the sub-continent. Word has been spreading recently about a number of pairs of Taitas residing on remote inselbergs in the Niassa area of far Northern Mozambique, and we’re hoping to get up there soon to check this fascinating area out.

How many? Well there are substantially fewer than 50 known breeding pairs of TFs on the planet. The jury is out on the actual population, but it is certainly well below 1000 pairs, and probably less than 500 pairs.

2) Has the population changed during the last decades?

We held an informal workshop on TFs at the last PAOC gathering in 2008, at which we tried to collate what we know about numbers and population trends, and figure out what we needed to do to improve our understanding of the status and conservation of this species. An important (if disappointing) conclusion was that we don’t really know enough at present to say anything definitive. However, information from Zimbabwe was cause for concern. The late Ron Hartley, together with an excellent team of local Taita Falcon enthusiasts (many/most of them falconers) spent years studying this species in Zimbabwe, and most of our current knowledge of the biology of the Taita Falcon stems from his surveys and observations of the Zim population. I think Ron knew of up to 16 nest sites in Zimbabwe, and suspected as many as 50 pairs were resident in the areas he and his team frequented. Since Ron died, Neil Deacon and others have done their best to keep tabs on at least some of the Taita sites in Zimbabwe, and their take on the current situation there is not encouraging. A high percentage of Ron’s known territories are no longer occupied, and even the long-established stronghold at the Batoka Gorges below the Victoria Falls has apparently dwindled from six known pairs to only one, and the species reportedly hasn’t bred successfully there for over a decade.

Similarly concerning information has come out of Uganda, with the four pairs reported from Mt Elgon in the 1980s apparently no longer there. The data to hand are by no means conclusive, and survey effort was almost certainly greater in the past than what is being brought to bear now, but indications are that the Taita Falcon may have decreased in some areas of its very sparse central African range. In contrast, we have done some quite intensive searching for these birds in South Africa in the last 5-6 years, and have managed to bump our known population up from two pairs (the first of which was only discovered in the late 1980s) to eight. In fact, we have found enough pairs to question whether these birds could possibly have been missed in raptor surveys conducted by some pretty heavyweight observers 30 years ago. The Taita Falcon is not the sort of bird that I would expect to exhibit quite sharp changes in distribution and abundance, but some of the evidence to hand, particularly from South Africa, suggests that such fluctuations might occur.

3) What is the preferred habitat of the species?

Good question! It is an obligate cliff-nester, and certainly likes big rock faces, although it is by no means restricted to only very high cliffs. It is also linked somehow with woodland habitats, with a penchant for dry woodland, and an apparent dislike for cliffs overlooking forest. Beyond that it’s difficult to say. My personal belief is that the Taita Falcon is a highly specialized predator that depends on habitats with a very particular structure and/or avifauna in order to make ends meet. Quite what that habitat structure might be I’m not at all sure. Ask me again in 10 years time!

Typical South African Taita Falcon habitat, © Andrew Jenkins

4) What is the preferred prey of the Taita Falcon?

Small birds. The literature would have you believe that it is a major predator of aerial insectivores (swallows, martins and swifts), and this is surely true in some areas, but has not really been our experience in watching Taitas in South Africa. We spent some time last summer watching pairs provisioning newly fledged young. They were under pressure to perform and, in some cases at least, operating on cliffs with thriving swift and swallow populations on and around them. We saw lots of hunting, but not one confirmed strike at an aerial insectivore, and only one delivered prey item that could possibly have been a swift. We struggled to identify what they caught and brought onto the cliffs, mostly because each item was so small and so rapidly processed. Red-billed Quealea came up a few times (even though we saw none in the local environment), and a possible Tambourine Dove. I’d be surprised if they took anything bigger than 80g with any regularity.

5) Is there a difference in prey size taken by males and females?

I really couldn’t say for sure, but the species is certainly sexually dimorphic enough to suggest that there is, and we’ve indications of this at the nests we’ve spent time watching in SA.

6) How do the birds hunt? Do they also hunt in pairs?

They are very fast and, like other large falcons, use speed as their primary means of surprising and catching their prey. They have an extremely chunky build, very short tails, and very hard, inflexible plumage. As such, they are built for high speed operation, even more specialized in their construction than the Peregrine. I’m not sure that they fly faster than Peregrines, but they certainly exceed them in terms of the frequency with which they fly fast, which is pretty much all the time!

Taita Falcon perched, © Alan Kemp

I think they occupy very small foraging ranges, but they can work those small areas very hard. Much of their chunkiness comes from massive pectoral muscles, which they use to generate a very high wingbeat frequency, getting them from A to B in double quick time even when there is no wind to hold them up. When the wind is blowing, to me they become quite buoyant flyers. Clearly they have a very high wing loading relative to their size, but in absolute terms they can use even moderate winds to huge advantage. They have a very interesting wing shape, with shortish outer secondaries just like a Peregrine, but then unexpectedly long middle primaries. The net result is a curiously blunt-ended, boomerang like outline, which must have some aerodynamic significance – perhaps it confers more forward thrust on the downstroke of the wingbeat? Coupled with an almost non-existent tail, the Taita is certainly a departure from the standard large falcon design. Understanding the function of this odd shape may be key to understanding the constraints within which this bird operates, possibly unlocking the secrets of its weirdly patchy distribution?

Given what I’d read about them before I started watching them, I expected Taita Falcons to hunt mainly in the high, open sky. This is where swifts like to ply their trade, and I figured the Taitas would get up there with them and hunt them down. This might well happen, and certainly the bird has the look of an effective swift hunter, but the Taitas we’ve watched on the Mpumalanga escarpment seem to hunt the woodland below their cliffs much more often than the wide open spaces in front of them. They are incredibly adept at snatching small birds from just above the tree-tops, in a way that I have never seen Peregrines or Lanners even begin to contemplate.

Yes, they hunt in pairs, but I would be surprised if they did so in a truly cooperative way. From the little I’ve seen, just like Peregrines, members of Taita pairs target the same bird at the same time, and may increase their chances of success in doing so, but there is little or no division of roles, and no sharing of the spoils afterwards.

7) What is the average breeding success of Taita falcons?

Not what you’d expect in a bird of this size. All other things being equal, allometric theory would predict that the much smaller Taita would lay larger clutches of eggs and fledge bigger broods of young than either Peregrines or Lanners. In reality this is not the case. The data are few, but four egg clutches are no more frequent in Taitas than in Peregrines, and they probably fledge smaller broods on average than Peregrines, and appreciably smaller broods than Lanners. So even though they are much smaller than sympatric congeners, they seem to be slightly less productive.

8 ) Is there competition with other raptors, for example Peregrines?

All indications are that they may struggle to co-habit with other, larger falcons. Certainly Ron Hartley noticed some Zimbabwean Taita sites apparently turning over to Peregrines or Lanners, and Kit Hustler noted how the Taitas in the Zambezi gorges near Victoria Falls were subordinate to Peregrines, and moved their nest ledges in response to changes in the location of Peregrine sites. However, in terms of their respective resource requirements, I think that there is probably quite good niche partitioning between the three species, and given the marked size difference between Taitas and the two bigger birds, I’d say there was less scope for active competition between them and either Peregrines or Lanners than there is for competition between Peregrines and Lanners. I suspect that the problem for the smaller species may be more about domination and possibly even predation by the larger falcons, than it is about competition per se.

9) What is known about movements of the falcons and dispersal of juvenile birds?

That’s an easy one – nothing. I think it’s probably fair to say that territory-holding adults are strongly centred on their nest cliffs and the immediate surrounds throughout much of the year. There must be some relatively long distance dispersal of young birds and non-breeders in the ‘floating’ population in order for the various small populations to remain genetically in touch, and records of injured birds being picked up a long way from any known nesting areas support this notion.

10) Is the species affected by pesticides?

As a close relative of the Peregrine – a species that seems particularly adversely affected by pesticides and chemical pollutants, there is always the chance that the Taita Falcon could be susceptible to these substances too, and we would be remiss in not considering this factor in our efforts to conserve the species. However, given that Taitas typically use habits situated away from intensive agriculture, and probably take prey less likely to ingest toxins than Peregrines, they may be less easily exposed to chemical contamination.

2010 SA Taita survey team (from the left: Anthony van Zyl, Andrew Jenkins, Lucia Rodrigues, Alan Kemp), © Andrew Jenkins

11) Are the birds illegally hunted for falconry?

I’m not sure that ‘hunted’ is the right term – harvested maybe? – and while there have been a couple of iffy incidents at one nest site in South Africa (and doubtless elsewhere too), my perception is that the Taita is not a species in high demand by serious falconers. It is too small and too specialized for classic falconry. While there seems to be some interest in trying Taitas as falconry birds (and this has been done to a limited extent quite legally in both Zimbabwe and the US, using captive bred stock), and perhaps a little more interest in captive breeding and hybridizing the Taita with other, larger falcons, I don’t think falconry – legal or not – poses a significant threat to the conservation status of the species.

12) What other threats do exist for the species in Africa?

I doubt that there are any clear and overriding factors. Rather, the very sparse nature of the Taita’s distribution, its very particular habitat requirements, and its small aggregate global population, make it vulnerable to a wide variety of factors on a localized basis. For example, small populations of fewer than 10 pairs may be affected by a highly location-specific variable – e.g. disturbance by adventure tourism at Victoria Falls, habitat loss to rural development around the Mpumalanga escarpment or to elephant overpopulation in the Zambezi valley, or pollution or impoundment of key river systems. Any such mechanism could quite quickly render previously high quality habitat unusable, resulting in localised extinction of the species.

13) What needs to be done to secure the future of the Taita Falcon?

I’m a great believer in the need to understand a species before planning a strategy for its conservation; in knowing how many individuals or pairs there are out there, getting a bead on current numerical trends, and developing a working understanding of the key resources which underpin the birds’ survival. Right now, I’d say that we are generally ignorant of most of these aspects of Taita Falcon ecology and biology. We need to learn more about the species, its requirements and its problems before we can hope to secure its future.

14) Are there any conservation projects for the Taita Falcon?

At the moment we are trying to learn more about the Taita population in South Africa – we (the South African Taita Falcon Survey Team – core members Anthony van Zyl, Lucia Rodrigues, Alan Kemp and myself) conduct annual surveys of the breeding pairs we’ve located in the Mpumalanga escarpment area, survey the area for new pairs, and we have recently started looking at breeding success, diet, hunting behavior and provisioning rates. To the best of my knowledge, this is the only funded research or conservation project on the species underway at present, and it is very small scale – amounting to not more than a couple of weeks of field time annually. In the past, This work has been sponsored by The Peregrine Fund, as well as by the African Bird Club, the Endangered Wildlife Trust, Birdlife South Africa and Glendower Whisky. We recently signed up with BirdLife SA/International as Species Guardians, and hope to tie our work with more opportunistic work being done by Simon Thomsett in East Africa, Neil Deacon and others in Zimbabwe, to develop a more Pan-African picture of the Taita’s status.

15) Can bird watchers visiting Africa help, for example by sharing their observations of Taita Falcons outside the known territories?

This is a difficult bird to see, and there are issues with identification, but any reliable Taita Falcon sightings, pretty much from anywhere except the very best known sites for the species, would be extremely useful.

16) What was your most amazing experience with Taita Falcons?

There have been a couple of memories that stand out. I guess the main reason I love watching falcons is the incredible speed and precision of their flight, and I remember watching at a Taita site near Blyde River Canyon with the rest of the SA survey team a few years ago wher we saw a great example of this. The birds we were monitoring were incubating at the time and the female was tucked out of site at the nest ledge. It was late in the afternoon and there was some weather blowing in onto the escarpment, the horizon looking dark and stormy, and the wind rushing urgently over the cliff-top. The male Taita was on a mission, riding the coming storm with irresistible energy and sizzling velocity. In an instant he transformed himself from a small, dense speck hanging in the sky, pinned against a curtain of grey looming over the Drakensberg crags, to a blurred flash of russet, scorching across the rock face then surging upwards again into the brooding heavens. He repeated this circuit several times. As observers, all we had to do was stand still and follow him in our binoculars as he described giant arcs in the air above and below us. And yet we struggled, left dazed and confused, losing and searching for him again and again as he jetted on his way.

Another memorable moment occurred later in the breeding season. Anthony van Zyl and I had hiked up under a known site in early December to check breeding success. We had waited on the slope below the nest cliff all morning in thick mist and rain, hoping that the cloud would lift and our patience would be rewarded. Around midday the weather brightened, and quite quickly we had a view of the cliff. As visibility steadily improved the Taitas came to life. It seemed that they had been waiting as expectantly as we had, and the scratchy whining of at least two newly fledged youngsters became more and more urgent. In response, the adults got airborne and started hunting, soaring in front of the cliff which was now completely clear of cloud. In the next 40 or so minutes we saw six strikes, most if not all of which were made at small passerines over the dense woodland immediately below the cliff, and all of which were successful and resulted in prey deliveries to the brood. There was absolute chaos on the cliff, with the two chicks receiving an obscene glut of food. At one stage we watched a youngster mantling over her second meal in ten minutes, as her father tried vainly to ply her with a third! We learned for ourselves that day what others have noted before us: that under the right conditions the Taita is a highly efficient hunting machine. And, as others have done before, we were left wondering why it is not more widespread and successful in the Afrotropics?

Alan Njuguna performs his "I believe I can fly" in praise of Vultures

In Kenya the event is organised by the Raptor Working Group of Nature Kenya and this year’s event was hosted by Ol Pejeta Conservancy in Laikipia District.  This third event was attended by 120 school kids from seven neighbouring primary and secondary schools.  For a ‘vulturephile’ you couldn’t beat the entertainment, rap songs about vultures, dances and poetry, all capturing the unique characteristics and importance of vultures. The kids got an up close look at some vulture skins and learned from members of the Raptor Working Group about special adaptations of vultures.  We encouraged the students to show off their artistic talents by entering an art competition with the theme ‘the role of vultures in the cycle of life’.  Twelve of the top artists were awarded prizes during the event.

A Masai dance in praise of vultures

Guest speakers challenged the students to spread the word about the importance of vultures and not to engage in practices that are harmful to vultures, particularly poisoning wildlife.  They also drew parallels between Kenyans’ negative attitudes toward wildlife and its decline. Speakers included representatives from Kenya Wildlife Service, BirdLife International, Laikipia Wildlife Forum, National Museums of Kenya, Wildlife Clubs of Kenya, and Nyahururu Bird Club.

Dr. Munir Virani of the Raptor Working Group and The Peregrine Fund presented our hosts with a beautiful vulture painting that was made during a previous IVAD event by Watoto kwa Kwetu Trust.  All the attending schools took home posters about the importance of vulture conservation and copies of Komba magazine, a children’s publication focused on conservation and produced by Wildlife Clubs of Kenya. In addition, students in all participating schools will receive copies of the colouring book, ‘African vultures’, produced by Raptor Working Group member Martha Nzisa. Finally, in honour of the late Kenyan Nobel Laureate, Wangari Maathai, students planted 150 indigenous trees within the conservancy.

This year’s event was a resounding success and once again the students surprised us with their knowledge and excitement about vultures. Through contacts made during the event, we will continue to spread the word about the importance of vultures to schoolchildren throughout Kenya by collaborating with education officers from the Laikipia Wildlife Forum and Wildlife Clubs of Kenya.

All the participants at IVAD 2011 after planting trees in honour of Kenyan Nobel Laureate Wangari Maathai

Funding for this year’s event was graciously provided by the N.E.W. Zoo (Wisconsin, USA).  Additional support came from Ol Pejeta Conservancy and The Peregrine Fund.  The organisers also thank Kenya Wildlife Service, BirdLife International, Laikipia Wildlife Forum, National Museums of Kenya, Wildlife Clubs of Kenya, and Nyahururu Bird Club for their support of the event.

Darcy Ogada is Assistant to the Africa Programs of The Peregrine Fund and is also Chairperson of Nature Kenya’s Raptor Working Group.

Immature Short-toed Eagle

Mellone, U., Yáñez, B., Limiñana, R., Muñoz, A.R., Pavón, D., González, J.M.,
Urios, V. & Ferrer, M. 2011 Summer staging areas of non-breeding Short-toed
Snake Eagles. Bird Study DOI:10.1080/00063657.2011.598914

The importance of the non-breeding fraction of raptor populations for conservation is well recognized, but little is known on the behaviour of these “ghost” birds, especially in migratory species. The Short-toed snake Eagle Circaetus gallicus is a migratory raptor that breeds in Europe and northern Africa, spending the winter in sub-Saharan Africa. Through satellite telemetry, a group of researchers led by the Estación Biológica Terra Natura (University of Alicante) and by the Fundación Migres recorded data of seven summering events belonging to six individuals hatched in Spain. Immature Short-toed Eagles left their wintering Sahelian grounds by mid-April, and after crossing the Sahara desert, the birds settled in Morocco and Algeria, thus not returning to Europe in their second nor third summer, and using one-three different staging areas for each summering. The eagles may have found suitable foraging areas along the migration route, where intraspecific competition was probably lower than at the breeding grounds, interrupting the migration journey to stay in these areas.

This study pinpoints that conservation of migratory long-lived species should not be solely focused in breeding and wintering grounds, but also should consider those events occurring in non-breeding summering areas. Download the complete paper here:

http://www.wildphoto.it/Mellone-et-al_S-Teagles-summer_BirdStudy.pdf

This article was provided courtesy of Ugo Mellone and his co-researchers.

I first met Alan years ago when he was the curator of birds at the Pretoria Museum. I was just beginning field and museum work on the African raptor field guide. After a few days of studying raptor specimens, Alan invited me to join him for a week of field work in Kruger National Park. Alan had already published many articles reporting his extensive raptor field work. During this week I was able to learn a great deal about African raptors from him, as well as study and take photos of them in person.
Alan was born and raised in Zimbabwe (then Rhodesia) and has always been interested in natural history, including practicing falconry. He received a PhD at Rhodes University, South Africa and first worked on raptors for and with Dr. Tom Cade for three years in the Kruger National Park. He later spent 32 years as ornithologist and curator of birds at the Transvaal Museum in Pretoria, South Africa. He and his wife Meg coauthored ‘Birds of Prey of Africa and its Islands,’ a mini handbook still in demand. Since retiring from the Museum, he has worked as a wildlife consultant. His main research interest is hornbills in Africa and Asia, but he has always included studies on raptors wherever possible, including recent raptors surveys in South Africa.
I have had the good fortune to spend much time with Alan over the years, both field and museum time, and every such time I learned more about African raptors. I’m sure that you and I will very much enjoy this interview.

Bill Clark Harlingen, Texas USA

All images in this interview taken by Alan Kemp or Keith Begg.

Adult Martial Eagle in Fligh. Krüger NP.

1) What is known about the current status of the Martial Eagle in South Africa and other countries?

The Martial Eagle is designated as Near Threatened in the 2011 IUCN and BirdLife International Red List over its total African range of c. 750 000 sq.km, but as Vulnerable in the official South African Red Data book. There is also concern for the species in Zimbabwe and Swaziland.

2) How has the population developed over the last decades?

I am only familiar with the status of the species in South Africa, where it has declined over the last few decades, not obviously in range but probably by about 20% in numbers. It occurs naturally at low densities, but in some areas it is now rare or absent.

3) Is there a difference between protected areas and non protected areas?

Within South Africa and Botswana there is evidence that it is recorded more in large conservation areas than in unprotected areas, most notably in the Kruger National Park and the Kgalagadi Transfrontier Park within South Africa.

Adult Martial Eagle perched overlooking savannah bushveld habitat, near Skukuza, KNP, 1990s

4) Is persecution still a serious problem for the Martial Eagle?

Persecution, direct and indirect, is still a cause of mortality in South Africa and Namibia, especially in areas of small livestock (sheep, goat) and game farming. Direct shooting and trapping, and indirect poisoning appear to be the main factors, but various education and awareness programmes in South Africa are having an effect in some areas.

5) How does electrocution affect Martial Eagles? What can be done to reduce mortality?

Electrocution is a cause of mortality in South Africa, but probably not a major one. Lower voltage rural lines, with the live wires close enough together to be touched simultaneously by such a large eagle, are the main culprit, but some of the deaths also result from collision with the wires. At the same time, the tall pylons supporting high voltage lines offer nesting sites in more open habitats. The national electricity supply agency works closely with conservation NGOs to rectify problems and encourage safe nesting. Problems with power lines are expected to be less in less developed countries with fewer supply lines.

Trapping adult Martial Eagles for ringing and/or wing-tagging for research, KNP, 1990s

6) What other threats do exist for the Martial Eagle?

An import threat, especially in drier areas, is drowning in open water reservoirs. This can be avoided by floating an exit structure (ladder, log) to enable birds to clamber out of the sheer walls, but requires the necessary education and awareness of landowners. Martials can live for long periods without drinking, although they do sometimes drink and bathe when water is available, but most drownings occur in arid areas where the need to drink or bathe may be more frequent.

Despite all these known causes of mortality, the primary threat to this large eagle in South Africa, and probably elsewhere in Africa, is almost certainly conversion or reduction in the prey-carrying capacity of its favoured habitats. Conversion of land to agricultural crop- and pasture lands, or to dense small-hold and residential areas, effectively excludes the species, while extensive herding and ranching lowers the carrying capacity of natural prey animals, especially when stocking rates are excessive.

7) What is the preferred habitat of Martial Eagles?

The most favoured habitats are open savannas, with a mix of indigenous trees, large and small, bushes and areas of open grassland. Such a diverse mosaic of plant forms, and the ecotones they produce, support both a high diversity and density of prey species. Martials extend readily into more open semi-desert habitats, and even into desert along wooded watercourses, but at a lower density. Wherever they occur, they require large trees (or pylons) as nest sites. They do not occur in more densely wooded habitats, such as parts of Mozambique and Tanzania, nor in forest habitats (where the large African Crowned Eagle is most common), and it generally avoids very broken terrain (where Verreaux’s Eagle and its main hyrax prey predominate).

8 ) What is the main food of Martial Eagles?

A wide variety of animal prey is captured by this large and powerful eagle, predominately vertebrates of 1-4 kg in mass, with the most frequent items varying from region to region depending and availability and abundance. Gamebirds, viverrids, squirrels and large lizards are often important prey items, but birds as large as Kori Bustard, mammals as large as young warthog, impala or baboon, and monitor lizards are taken at times. Most individuals do not take livestock, even in farming areas.

Trapping adult Martial Eagle for ringing and/or wing-tagging for research, KNP, 1990s

9) Do Martial Eagles compete with other raptors for food or nesting places?

Martials often occur in habitats that support a variety of other predatory birds, especially in extensive areas of natural habitat and/or conservation protection. Their main competitors of similar size are usually separated by habitat preference, such as African Crowned Eagle (forest), Verreaux’s Eagle (rocky habitats, cliff nesting) and African Fish-Eagle (waterways), or by hunting behaviour (Secretarybird, Ground-Hornbills) but where their ranges overlap there are sometimes competitive encounters, mainly about prey that one or other species has flushed and/or captured.

Other predatory birds that interact with Martials include those that regularly pirate prey (Tawny Eagle, Ground-Hornbills), and those that sometimes take over their vacant nests (various eagle and vulture species).

In general, Martials are the largest, strongest and best-adapted predator in this preferred habitat, and so competition is usually low.

10) What is the typical hunting technique of Martial Eagles?

Martials hunt from a perch, usually in a tree but sometimes on a rock or even on the ground. However, their main hunting technique, making use of the long broad wings and expert soaring ability, is to soar over their extensive home range and then descend on prey spotted below, either in a long shallow dive or, less often, a steep fast stoop. Rarely hover during strong winds when hunting, but much less so than the similar-looking Black-chested Snake-Eagle. Sometimes lands after an abortive strike, and then waits at perch for a second chance. After killing large prey, may perch nearby and return at intervals to feed, exceptionally for five days.

11) Do Martial Eagles also feed on carrion?

They will pirate prey from other predators and even come to feed on carrion, but not on a regular basis. Some of the instances reported as livestock kills are known to be actually attraction to carrion.

12) How often do Martial Eagles breed and how many eggs are usually laid? Do sometimes more than one chick fledge?

A Martial Eagle female only ever lays a single egg per clutch and so raises only a single chick at a time. Laying commences usually during the driest season (e.g. April-June in southern Africa), and pairs often attempt to breed in successive years. As many as one 30-50% of pairs may not breed in a given season,because conditions are unsuitable and/or a juvenile is still being raised, and overall pairs fledge on average about one chick every two years. The long nesting cycle (c. 50 days incubation, 100 days nestling, 3-4 months post-fledging dependence) means that nesting starts when prey visibility is best and continues into summer when prey numbers are highest.

Friend Richard Harland with chick at base of nest tree.

13) What is known about the dispersal and movements of Martial Eagles, especially the juvenile birds?

Adult breeding pairs appear to be resident and sedentary once they have established their large territories (c. 150 sq.km in wooded savanna to 250 sq.km in semi-desert). In areas of good-quality contiguous habitat there may be few dispersal sites for juveniles/immatures during the c. 6 years before they attain mature plumage (as in several large conservation areas), and so they wander widely (although exact details are sparse) and predominate in accidents in what are probably less productive marginal habitats.

14) What natural enemies do Martial Eagles have, for example can Leopards or Baboons be a threat to the young in the nest?

Being so aerial, large and powerful, for Martials few instances of predation are reported, even at nests, and most known mortalities are due to accidents. Baboons are diurnal and likely to be driven away, but leopards are nocturnal and might surprise and adult/chick on the nest. Most nest failures by known ‘predation’ involves egg- and/or chick-collectors, or other human persecution.

15) Do you know of any conservation projects for the Martial Eagle?

There have been several field studies of Martials in South Africa, Namibia, Zimbabwe and Kenya that I am aware of, mainly in large conservation areas but also in livestock and other farming areas. These have supplied some of the details on biology that are necessary to organise effective conservation management strategies, but in the end depend on the priorities and will of the residents of the countries within the species’ range. I am not aware of any comprehensive current projects that specically target this species.

Martial Eagle chick on nest in mountain 'acacia' Brachystegia glaucescens with lake shore in background.

16) What should be done to secure the future of Martial Eagles in Africa?

The primary effort to secure the future of this species in Africa is to maintain as many large areas of pristine, or near-natural habitats as possible. These would supply a productive basis for the population as a whole, and probably ensure that increased mortality from various anthropogenic effects do not precipitate a general decline. In practise, this requires local conservationists to secure and protect whatever natural habitat they can, within the realities of the human requirements within their region. How this is achieved in the face of human populations growing in size, affluence and ambition, and divided into diverse ethnic and political units, remains the real challenge.

17) What other raptors would benefit from such conservation measures?

African savannas support a high diversity of raptor (and other animal and plant) species, so ensuring the protection of viable populations of an eagle with such large spatial requirements as a Martial Eagle will inevitably protect a high level of biodiversity. For example, in the 20,000 sq km Kruger National Park of South Africa (now doubled in area as a transfrontier park) there are an estimated 130-150 breeding pairs of Martial Eagles, among a total raptor community of c.70 recorded species, and where, with luck, one can see 26 species in a single day.

18) What was your most amazing experience with Martial Eagles?

While I was busy ringing a large Egyptian gosling near a small dam, an adult female Martial Eagle passed high overhead at a height of about 200 m above ground. I released the gosling once the eagle was at least 1 km away and, as it waddled off to the water, the eagle banked, made a long 2-part stoop, first away and then back, and ended with a rushing attack just as the gosling reached the safety of the water. The distance at which it spotted the potential prey, the rate of its attack, and the spectacle of the near-miss at close quarters was unforgettable.

Crowned Eagle pair with chick, © Simon Thomsett

Movements

To my knowledge no population of Crowned Eagles migrates, or has seasonal movements. One might expect juveniles to move after foraging parties and disperse widely, but not adults. They appear to be very sedentary, but appearances can be deceptive and further study may show unexpected swapping of spouses, hedge hopping, cuckoldry and large movements of some individuals. In the housing estates of Tai, urban lifestyles may be expected! Leslie Brown once noted an adult Crowned Eagle after a rain storm in Tsavo on a small and dry hill. It must have been on passage. I have seen an adult Crowned Eagle in a sparse river bed at Lewa Downs far from its usual habitat and assumed it was just passing through. None had visited the area for years, and none did so since, so it may have been on passage. Juveniles can appear in bizarre places, such as the Nairobi Golf Course near the city centre but this is not evidence to say that they are living there, and thus prospering (as was the suggestion).

Annual or Biannual reproduction
One might expect that the ‘forest’ eagle reproductive recruitment is higher than that of the ‘bush’ eagles because of greater competition and presumable greater risk of violent death. If better and more assured nutrition is a factor then again one would expect the ‘forest’ eagle to produce more. Unlike the ‘bush’ eagles they do not share their territory with Martial, Verreaux’s and African Hawk Eagles…but with each other. There is no greater a direct competitor than one’s own species. Their close proximity and the vicious engagements they must surely endure from neighbouring pairs means that it is likely that mortality from territorial combat is higher than with ‘bush’ eagles. The fact that the ‘forest’ eagle have a particular taste for adult male Red Colobus, the ignoramus bully with forearms longer than mine, also makes one ponder if they get wounded by prey more than the ‘bush’ eagles. Despite being later proved wrong when I caught a couple of recently fledged youngsters in Tai that looked like second year birds I kicked around an idea with Susanne and Guy Rondeau that they also matured quicker, because they had to. In a more violent world maturing quicker and breeding faster would be beneficial and perhaps it may happen. That one chick per annum has been recorded in similar South West Ugandan forests (which sent ripples of anxiety through Crowned Eagle lovers the world over) could be explained as a one off, premature death of previous chick, or that locations of endless and stable bounty could turn out more young. It may be one of those things that can occur in super-productive and perhaps more violent forests. Annual breeding for a species with so long a reproductive cycle must require great effort only possible or necessary in an area with food abundance and high mortality.
In captivity Crowned Eagles could breed each year and I have deliberately accelerated or delayed them by keeping their chick with the pair. A begging youngster is a definite libido crusher. Once removed (after at least 4 months) sexual activity quickly returns. Returning the chick once mating and nest building commenced saw the parents divided with the adult male being attentive and the adult female being aggressive. In this case the chick was a female, and so it could have been considered sexual competition. It is unwise to assume that the Crowned Eagle (or any other) is an obligatory biannual breeder irrespective of extraneous considerations. If the chick has dispersed or died earlier than usual there is nothing stopping pairs recycling in equatorial and tropical Africa. But I understand that there is enough evidence to suggest that the breeding cycle is too long for a usual, temperate world (South African) annual breeding cycle.

Hunting methods
I have had unique opportunity to watch Crowned Eagles hunting in trained and wild conditions. I have trained some 15 Crowned Eagles over the years, mostly captive bred, but some passage and haggard birds as well. I must have seen a few or more hundred kills, mostly hares and springhares (taken at night down a spotlight) and vervet monkeys during the day. The wild ‘taken’ (all rehabs) adult birds would, one must assume, replicate the same hunting methods they utilise in the wild if given the chance. I noted among their repertoire of techniques blind approaches to prey, using contour and tree trunks to hide their attack. Monkeys and hyrax feeding on limbs in full view causes the eagle to freeze and lengthen, until one walks with it behind an obstacle. Only then does the eagle flare its facial disc, crane its neck and show signs of intense excitement. When sure that all members of the prey are unable to see its approach it launches its attack straight at the individual most likely to be the greatest surprised. Whipping around the tree trunk at the last second it either connects with the prey, or sends the whole group into disarray and panic and misses. The extreme interest shown in prey that goes behind an obstacle is common with all Crowned Eagles, no matter their age or upbringing.
I had one female, Girl, a wild taken adult who would fly at a 45 degree angle from the fist directly over running Kirk’s Dik Dik, then plummet vertically down on them from as high as 10 to 20 metres. Her last second vertical approach was extremely fast and manoeuvrable, capable of spinning her around a bush. It had an almost 100% success rate whereas her captive bred offspring would simply tail chase and usually miss the same prey.
Recognising that any falconry-type hunt is poor evidence of methods used or prey species taken in the wild by wild eagles I shan’t document the methods used by the developing young, other than to say that hunting is learned, and they adopt some particular patterns as they mature. Young Crowned Eagles are particular poorly developed when it comes to recognising prey, and dissecting it. If captive bred birds are familiar at the nest only with a certain selection of whole prey they happily consume and dissect it when latter presented with them away from parental supervision. But if suddenly given a new species, such as a dead genet or Syke’s Monkey , they stare at it with confusion or even fear. Clearly parental choice delivered to the nest will be handed down to their young. Young eagles making their first few kills in captivity are inept to a degree seldom seen in other eagles. They bungle attempts, give up quickly, fail to anticipate avoiding action and often show fear. In killing they show a quick ability to learn which end is best to squeeze. Very soon, after a series of catastrophic mistakes and severe beatings they can subdue large prey by a head and shoulder grip. But once they have killed something they are keen to experiment and can be fool hardy. I suspect that they largest kills are taken by juveniles. This is the case with most raptors.

Mute, © Simonn Thomsett

I had better opportunity to witness these developing methods while hacking captive bred Crowned Eagles in Tsavo West, Mathew’s Range and Ol Donyo Laro over a ten year period. Nine chicks were born, hatched and raised with their parents Rosy and Girl at my home in Athi. They were usually removed at 4 months of age and then settled outside with a foster parent or older sibling to whom they sometimes associated and solicited food. Crowned Eagles are very easy to train but were never allowed to be tame and confiding of strangers as would most falconry birds. They were always managed to keep a reserve against people lest they not fear humans when wild. These trained eagles knew how to hunt at home taking hares, spring hares, mongoose, genets, Vervet Monkeys and much less often Thomson’s Gazelles and Black backed Jackal. The largest kills have been adult female Bush Buck and Impala, as well as their calves. They tail chased them then flattened them and a very basic and thuggish manner. The trained eagles were taken as ‘pairs’ for release and they profited enormously from being together. ‘Pair’ release is a method I would recommend for any re-introduction programme of large and socially complex raptors. They would hunt together, working a tree or bush until prey was flushed into the other’s path. This would often be by accident not design to start with then develop into a segregated task. After years of being together in the wild they would develop a working sympathy with each other that I was able to watch and not interfere. Usually the male would be ‘told’ to go in by the squeaking female. The female would sit high, look keenly at the prey beneath her and squeak and whine in a fever of over-dramatised intent. The male would appear to be driven to make the first courageous move, sometimes wriggling his way on foot in through dense thicket towards the hiding prey. She would reserve her pursuit and strike for the flushed animal, but as often make a mess of it by prematurely launching at the prey when she thought the male was within grasp.
Often one would land on top of a tree full of vervet monkeys. As they piled out of the tree the other (male usually) would take one on the way down or on the ground when running directly away. The level of co-operative hunting was unquestionably altruistic in that one would accept that it could not capture the prey, but serve only to flush it. Smaller prey was reserved for the male (such as female or juvenile vervet), larger (adult male Vervets) for the female. At all times the male would immediately relinquish prey he had caught to the female, even before it was dead although sometimes both would foot the prey especially if it was large enough to allow space.
None of these methods are unique for raptors. What emerged that only recently dawned on me as a probable ‘new’ hunting method worth publishing is as follows. What I witnessed was the quick and vicious attack on prey that appeared only to bowl it over and wound it. I had long ago been impressed by the ability of this eagle to seriously wound prey and leave it alone to die. In 1978 Rosy killed a Bushbuck female in circumstances I then did not think was normal. He hit the running female (only when it disappeared behind trees) that ended up upside down in a hedge. He hit it and was swung off it almost instantaneously. While deliberating what to do about the unfortunate Bushbuck, and worried about the fierce glare of Rosy in the tree above, it collapsed. I pulled it out while moribund to have Rosy violently push me aside and set about stabbing it along its entire length of neck. He then leapt back when it stretched to die. On PM I noted a huge subcutaneous bag of aerated blood, punctured rib cage and lungs as well as large haematomas on the neck. It had died of blood loss.
At a hack site at Finch Hattons Tsavo West a ½ grown bushbuck, always in close attendance with its mother, greatly excited one female eagle who followed it for 2 days. She made exploratory runs over it, to be thwarted by the mother turning to face her approach. On one occasion the eagle landed near the calf and the mother ran in and violently knocked the eagle away. The calf was inseparable, never leaving its mother’s side because of this attention. The bushbuck would associate more closely with Yellow Baboons, primates that these eagles had learnt to avoid. But wherever the Bushbucks went the female eagle followed. Suddenly the eagle tried a different approach and flew straight at the calf and knocked it over and continued on. The mother Bushbuck and attending baboons had no time to react as it was over in a flash. The eagle made no attempt to halt but flew and landed to watch the result. The calf, immediately got up and stayed by its mother with it ears hanging low. I found blood on the ground, and clearly the calf was badly wounded. The eagle then followed the calf relentlessly for two more days, showing evident curiosity (by raising its crown, craning its neck, standing on two feet, leaning forward and flying to different trees to keep them in view) every-time it lagged or stumbled. Finally the calf was unable to keep up with its mother and the eagle killed it. I did not see the kill, but arrived very soon afterwards to ascertain that the first impact had left a lethal wound that had gone septic and punctured the peritoneum making a large aerated subcutaneous lesion. I am sure the calf was unable to keep up and its mother had walked away and was unavailable to help. I saw a vervet monkey struck and left, in similar manner. It sat in a tree for hours, unable to keep up with its troop before it swayed and looked very sick. It was taken at near death when it offered no resistance about two hours after being attacked. The reason for so a long hind talon (measured at 10cm in one female and 9cm in two captives) is perhaps now evident. It is, as I liked to tell visitors to my eagles (making a few friends no doubt sigh with despair at its repetition here) “The largest killing implement on the African continent”!!! The needle tip, extraordinary length and incredulous strength of grip will, in an instant, puncture vital organs of any animal weighing under 50kg. To stab and move on would seem the stuff of undercover espionage agents armed with umbrellas, but it has the same effect. The two groves down the edges of the talon may harbour sepsis-causing bacteria if the caked blood and tissue clinging there is an indication. Like a Komodo Dragon the Crowned Eagle may have developed a “bite and retreat’ method of hunting. Even if sepsis is not the result, the effect of a deep stiletto dagger wound, followed by days of patient waiting is a very effective hunting method. It is a reptilian method not necessarily showing great intelligence that I believe is used by Crowned Eagles.
The vital organs lie close to the surface and surprisingly the heart is vulnerable to a relatively small puncture wound across a board range of body weights. For example, a mouse may have its heart 3-4mm under the skin. A rabbit, some 10 to 20 times heavier has a heart 10mm under the surface and an Impala some 25mm. A raptor with a 2.5cm hallux such as a Long Crested eagle, kills neither impala nor hares, but mice. So why the over-endowment? Perhaps it is because although the talons are long enough the eagle has too weak a grasp to puncture an impala’s chest. But a Crowned Eagle can extremely easily puncture an impala’s chest and break every rib within its span of foot simply by gripping it without the assistance of a fast contact speed.
The Crowned Eagle is an incredibly powerful eagle habitually killing as far I understand the largest prey of all eagles.

Crowned Eagle, © Simon Thomsett

Conservation of Crowned Eagles
Markus asks what should we do to conserve the Crowned Eagle. All matters of habitat change, water loss, declining food productivity is directly related to human population. While TIME magazine can attempt to dismiss the reality by saying we could all stand on Manhattan Island, if we all breathed in 500,000,000 would all fall into the ocean. There seems a reticence today to avoid broaching the subject of human over-population, whereas in the 1970s this was not so. I drove recently Kampala (Uganda) from Nairobi (Kenya) and saw (apart from kites) half a dozen raptors, 2 dead zorillas, and one live Reedbuck standing in an irrigated plantation. Apart from two small forests (each about 2km in extent) in Kenya, and 2 small forests (One 4.5km and anther 3km) in Uganda I saw nothing other than dense human populations, towns, shambas, Sugar Cane, towns, exotic plantations, towns, cereal crops, etc. The trip back covered some 1200km. Potentially the Rift Valley and lake basin, with super-fertile soils, varied topography and altitude, straddling the equator, should hold one of the greatest abundance of life found on the planet. And so it does, but it is mostly human. It unquestionably lies within the optimal core of former Crowned Eagle distribution in the sub-region. I doubt such a bio-impoverished or human dominated landscapes is what westerners expect to hear of a region as large as the British Isles lying in the heart of Africa. But similar rules apply elsewhere. Combine tremendous land fertility (such as the Ganges flood plain) with subsistence farmers and you tend to get biomass converted into people. It happens in India, Far East, Burma, Malaysia and sub-tropical Indo China, Latin America as well as Africa. Only high education and a new ethical world order on principled restraint to limit our full human population potential can intervene. But there is no indication that it will and there is certainly very few leaders who today would dare champion these matters.
In the Ethiopian bio-geographical zone, loss of net primary production between 1980 and 2000 is about 18%. “Moderate” desertification in Kenya stands at 64% and “severe” at 21% (1997) These percentages are expected to increase each decade and has already forced people from former high productive areas to drier marginal regions. Our urban and rural population is predicted to meet around 2050 with a total population in excess of 80 million. Unlike global predictions of a population plateau, ours still climbs off the chart at 45% angle, with no predicted stabilisation point. Wildlife is expected to parallel these changes with proportional declines. Education cannot be expected to catch up with the task and apparently nor can catastrophic examples of the folly of such action force change.
The accumulated effect of anthropomorphic factors appear to seal the fate of Crowned Eagles in our region; but is this applicable throughout Central and Western Africa? Most nations show similar trends and to expect different is to hope for a change in humans.

Given that people have repeatedly demonstrated their ability to exceed the holding capacity of the land to sustain them (as noted by Leslie Brown in the late 1970s), and given the lack of responsible leaders willing to address politically sensitive issues related to population control, it would be foolish to expect a long term future for Crowned Eagles. For the last few decades there is no question that protected areas have secured the Crowned Eagles and they continue to do so as long as they are allowed to remain.
If asked where financial resources should be spent in order to conserve Crowned Eagles I would roll out the standard (tailored for foundation) response. Namely stick to the buzz words of the day, “Create local capacity……… using Crowned Eagles as indicator species………securing environmental services through the conservation of water catchment areas………..working with marginalised communities to achieve………..Community based conservation projects………blah, blah, blah. Put one beer in me and I’d say what the heck, it’s all a waste of money because of the juggernaut of humanity. If you think that is bad, then put a lot of beers into my colleagues after the stand up show (conference) in which they enthused optimism and be prepared to gulp down much Prozac©, lest you feel a tad worried about the survival of your own children! There is a peculiar discrepancy between the personal thoughts of a conservationist, and their professional stance. There has to be otherwise they would be out of business. The business obliges optimistic outlooks and when none are obvious they may be invented. If only for a little while till humanity has a complete change of world order. Many projects must go ahead without a truly achievable end objective and this leads to an uncomfortable duplicity in the organisation/individuals concerned. Entering a project bereft of confidence is the sad lot of most conservationists in out part of the world.

Finally Markus asks “what was your most amazing experience with the Crowned Eagle?”

Once when I was a lad I was crawling on all fours through a forest path on the Amboni river near the Aberdares looking for what I hoped were Golden Cat tracks. All of a sudden the Robin Chats, Bul Buls, cicadas and all the animals went quite. The hush then turned to an avenue of alarm, from hornbill to monkey, from monkey to bird; and this onward rush of terror fled toward me! Stuck in a well trodden low tunnel I stared ahead down 100m of clear sun dappled view and was filled with primeval alarm. I knew a fast approaching predator was on its way and it was coming straight for me at a frightening pace. There ahead I saw her, golden eyes and silent, approaching at leopard height at unfathomable speed as steady as an approaching jet fighter. I distinctly recalled the fact that her wings were half closed and unmoving. I saw too the pattern of light and shadows flashing across her unblinking eyes. I stared enchanted, as must a man in front of a charging tiger, aware of the futility of action and mesmerised by the beauty of my attacker. I closed my eyes for the impact, heard a loud bang over my head, heard a sudden explosion of growling colobus monkeys and felt a light fall of twigs and leaves as well as the thump of air. She had punched her way through the brush above me. In that fleeting second before impact I noted a frown of disgust. I was not what she had hoped. If I had been I would have been dead.
I guess I had experienced a very rare thing. I was targeted as prey and she had launched her attack from a hidden and distant position. She had known all the paths, had heard my progress, perhaps seen other birds and animals note my presence. Undetected she had started an attack and had entered the tunnel at so fast a rate that she had no need to open her wings. She must have done that same path many times before.
I have been hurt badly by wild and captive Crowned Eagles, seen them kill enormous things, had them die after weeks of care in my arms, seen them hatch out of eggs and lived with them longer than any other relationship, human or animal. But that one simple thing is the most memorable.

Male Crowned Eagle, © Simon Thomsett

Replacement rate and longevity

If persecution was a factor then the breeding biology of the Crowned Eagle would predispose it, above all other raptors in Africa, to a gloomy future. While annual and biannual breeding has been recorded and its ecological perspective pondered, annual breeding is rare and probably related to the success, or not, of the previous season. Usually and possibly throughout its range it fledges about one chick every two years. The chick takes an inordinate time to reach independence and that alone is good enough reason for their slow reproduction. For a not-so-very large eagle it is hard to explain its slow fledgling and maturation period. I have seen begging 9-11 month old chick on the nest of an incubating pair, and also saw that same pair feed a 2-3 year old juvenile, possibly unrelated near their nest. That may suggest that recycling can be started before the chick fully disperses. I used to breed them in captivity and “pull” their chick at aged 4 months, to make them recycle for the next year. When they had egg losses (due to cobra and Honey Badger) they could lay again within weeks. It is interesting to note that on occasion Girl would lay two eggs. On one occasion when both hatched I saw no active Cain and Abel aggression other than the elder chick tweaking the toes of the younger. I did separate them lest one die of starvation.
The phenology of large raptors on the equator, especially those with stable prey base can hardly be expected to be precise. I’ve been uncomfortable with the dogma that there should be a season…simply because it is so in temperate places, but I must admit that come July, Aug, Sept my old pair would like to lay….sometimes irrespective of weather. Why I cannot fathom. But should I bump them into breeding in the first half of the year they would oblige (by giving them a stream of highly nutritious food (monkeys, springhares, small gazelles, etc)). In Kenya wild laying dates would seem to favour the latter 6 months of the year.
Female chicks take longer to fledge by about a week to a month and they take much longer to learn how to fly properly and hunt than males. While there may be a size overlap between male and female young (as well as adults) males are snappy, make their first flight and first kill quicker, certainly so in captivity. But in the wild I have also seen it so and presume that should a pair have a male, they may breed sooner the next year, than if they had a female chick.
The first year plumage is surprisingly varied. The most usual is the pure white fronted face, bib, chest and flanks and undertail as well as legs, often with a pinkish red wash on the upper chest. Slightly less common are those which one could easily have aged as two to three year olds. These just-fledged chicks, have darker patched faces, freckled bibs and slightly barred chests and spotted legs. While the pale ‘morph’ young just prior to leaving the nest usually have unmarked tarsus, they soon get spots on the front part of the tibio tarsal joint. I had at one time thought that there was a difference in the first year morphs between East and West Africa, but both Susanna Shultz and Guy Rondeau noted similar polymorphic first year birds in the west. By 4 months post-fledgling the inner thighs, previously poorly covered with downy type feathers, are covered with small feathers. The tibio tarsal pad is still bare and obvious up until it is a year old, whereupon it vanishes only to return to incubating females. Eye colour is variable too with some having khaki light brown just prior to fledging and others with adult-like yellow ochre eyes.
The plumage variations between sexes, as offered in some field guides is inconsistent and do not always apply. The various amounts of orange/rufous marbled patterning on the chest has been suggested as being sex linked. Some males have much orange on their chest and females have less, almost monochrome chests. But this does not always hold true. I suspect that most females have one less bar on the secondaries than do the males. While usually so it is not invariably the case. I have a suspicion that large females show female traits more strongly than smaller females; and small males show more male traits than larger males.
Plumage maturation therefore appears to depend upon sex, their size, and their particular first year morph, to say nothing of stress and variable nutrition. Of 9 young, 5 were male. Of these 2 males were larger and they matured slower than the 3 smaller males. It should be noted that in captivity moult can be accelerated or delayed by feeding regime and exercise. All these birds were trained, flown and hunted and therefore were most likely to follow a wild birds moult pattern. The females were less variable but all began their first flight feather moult a month or two later. They would half complete wing feather moult before the first deck feather fell. But not always. The first flight feathers were moulted out at 9 to 18 months, showing a marked lack of adherence to the calendar. Males are usually inseparable from adults at 4 to 5 years. Females (usually) taking half a year or more to mature. The only indication of juvenile feathers at this age are light crescents edging the distal part of each feather on the upper wing coverts near the carpals, obvious a year previously but at 4 to 6 years becoming very faint. Irregular moult can certainly be protracted due to stress, nutrition or work, and while it is usual for one moult will be overtaken by the next, some old ragged feathers may be retained. 3 and rarely 4 moults can be seen in an individual. Of particular interest is their ability to moult damaged feathers early. If any primary is fractured and left so (not imped), it will drop sometimes 10 months earlier than expected. My old male has a poorly healed humerus and fractures feathers on that side with frequency. He has replaced primaries in this wing many times more than on his good wing. At 32 years he developed a single white tipped greater upper wing covert, in mid wing, which increased in size at age 33. His mate a similar aged female also now sports a single white tipped feather on the same wing and same location. These maybe senile related.
Moult in Crowned Eagles is therefore a complex affair, but I suspect more temperate eagles would adhere to a calendar a little more fastidiously.

Behaviourally Crowned Eagles are nervous, constantly alert and on edge. Females are more phlegmatic but never docile. They are highly intelligent, cautious, independent and inquisitive, unlike African Hawk, Tawny or Verreaux’s Eagles. In their training and management they are more like goshawks than Aquila eagles. Being permanently curious and edgy would seem to be a common trait for most forest raptors. I understand that the Harpy and Philippine Eagles are much less nervous however. While I might be poo pooed for noting ‘intelligence’ I have no end of examples that place them in a unique position over all other African eagles, particularly when they hunt. They cannot be induced to hunt large prey by increasing their hunger, as would a Verreaux’s or Tawny Eagle. They may show moments of cowardice that while shameful, may expose a unique aspect of their hunting strategy. They are variable in temperament too as individuals to a degree greater than that found in most other raptors.
One thing is for sure, they are a highly variable species, in colour, size, maturation period, behaviour, prey preference, habitat use and requirements.

Crowned Eagle, © Simon Thomsett

Because of their low fecundity one would assume that Crowned Eagles were exceptionally long-lived. My male Crowned Eagle called Rosy was over a year when I got him in 1978. His mate Girl is about the same age. She is fine today and not a whit older, but Rosy had to undergo a bilateral cataract operation. Importantly it was not senile related and the eye surgeon was amazed to note that he had the immune response of a human child. They still have the will to breed, nest building and even mating. I would credit some wild Crowned Eagles in benign environments at easily reaching their mid thirties, and it cannot be impossible for some to reach 50 years or so, as can other large raptors. However when I visited Susanne Shultz in Tai Forest, Ivory Coast I was shocked at just how close those pairs were to each other, for there is one thing I know, battles between pairs are violent and life threatening, especially if you have those feet. I cannot imagine that those packed in, jowl to jowl, territories do not have murder as one of the main causes of death. Tai is a tough neighbourhood, whereas our nice clean community of more widely spaced eagles that we see on cosy wooded hill tops in Kenya, would be less likely to indulge in such behaviour. Mind you, given that our Kenyan territories are often fragmented patches, there may be deliberate take-over attempts for these isolated territories. Leslie Brown had birds that occupied one nest 9, to 13 years, but these do not discount territory moves which may well happen. I had one adult female who later died brought in with deep wounds that were certainly inflicted by another eagle. Another natural cause of death expected to be exceptionally high for this species is injuries incurred during struggles with heavy and well armed prey. In witnessing eagles killing vervet monkeys, a relatively small monkey, I have been impressed by the way some monkeys will fight back with their arms, hands and teeth. I once arrived just after a young female Crowned Eagle had attempted to kill a full grown female baboon and suffered the wrath of troop members. She would have been wounded or killed had I not intervened. I treated a wild female for an ocular inclusion in which debris had been injected into the eye and destroyed the lens. There was another lesion the same distance as the separation between Suni horns and I assumed that she had been head butted. Tom Butynski concluded that a monkey had harmed a chick in the nest that later died in S W Uganda. I have lost two released eagles, one to a leopard that surprised a male on a monkey kill in the rain, and the other from a crocodile that took a female as she ate a young bushbuck kill near the water’s edge. Other causes of natural death are probably starvation and disease. But trauma related deaths would seem to be high for this species.
Of deliberate human persecution I have personal recorded them being shot by an expat with Burmese cats in Karen, shot by a big cat conservationist for eating geese in Karen, shot by sheep farmers in Mweiga and Timau, shot by KWS rangers in Elgeyo Marakwet and Rombo, shot with arrows in Cheranganis, poisoned in Kibwezi and Maua Hills (Machakos) and Cheranganis, caught in snares in Cheranganis and finally nest trees deliberately cut down in Cheranganis and Mweiga. Another male was beaten to death in a corn house whilst killing a dog in Elgeyo Marakwet. Of accidental deaths I saw a juvenile female with and amputated wing severed by a snare set for ground game in Karen forest. One male at Ololua attempting to take domestic geese in a chicken wire pen in Leslie Brown’s old house was snagged but fortunately rescued.

Export and trapping

Markus asks if the bird trade is any threat. The amounts reaching their destination under permit may be sustainable, but those caught to supply them is a different thing. Given the amounts exported I would doubt if it would be a global threat, but I do consider their brutal trapping and subsequent terrible husbandry and resultant mortality a threat to local populations. The trade is of course an effrontery to conservation.
I recall two Crowned Eagles being exported from Kenya, one in the 1960’s by Cunningham van Someren, and another in the 70’s by Don Hunt. Both went to zoos. I suspect a few more were exported, but not many, chiefly because of the difficulty in handling them. From my experience in rehabbing raptors, I have been appalled at the handling and husbandry methods made by the public and trained government officials as well as most vets. I once saw a tethered Martial Eagle, meant for export in the 70’s with both legs tied with a piece of rubber inner tube, wrapped around an open fire in a hut. The children were busy taunting it with a stick. The trapper was a professional and I was unable to confiscate the bird. It must have died for it never reached the export company run by an internationally famous conservationist. I have seen many birds and raptors in capture holding pens, some feeding on each other, in conditions where mortality or irreparable damage is virtually guaranteed. From what I can glean from the highly secret businesses in Tanzania and Uganda, similar treatment is the rule. I once estimated, based on the trappers, and the company owner’s own admission, that some one in ten captured raptors would survive to get put on the plane.
I dread to think what lengths of brutality a trapper would go in restraining a Crowned Eagle, an animal that could maim or kill a human if given half a chance. I cannot imagine what sort of trap they would use, or how they would house it. But you can be assured that the process is cruel and life threatening. I would expect a higher mortality rate for Crowned Eagles than most raptors, simply because they are very awkward birds to handle and are easily stressed and likely to self mutilate against cage walls.
If for every one bird exported one must capture 10 birds, and each bird is an adult, the impact is considerable. This is an open question as no-one knows the details, nor is one allowed to know even when asked by officials to make an opinion.
The significance of the removal of adults, juveniles or chicks is not considered in the various regulations. Despite very good reasons to separate these age groups when it comes to a harvest quota, it is not done. Falconers of old never took haggards, or only rarely when they knew they were not breeding. They took passagers or eyasses. These juvenile birds experience such high mortality that it makes little difference to the population as a whole if some are removed. Established breeding adults are crucial to the survival of the species and represent a small fraction of the yearly crop of young and as such should be left alone. With this ancient wisdom, why is it that modern biologists have yet to enforce the same protocol in the raptor export business and within the CITES regulations? The absence of deferential treatment or harvest rates for age groups illustrates an oversight.
The removal of unfledged chicks or eyasses from the nest, if done smoothly and unseen can be least disturbing. This applies to nests with multiple young from which the adults are allowed to raise one or more chicks undisturbed after some have been removed. But Crowned Eagles raise one chick every two years, and their investment in that one chick and nest site is monumental compared to almost all other birds of prey. The removal of a single eyass out of a Crowned Eagle nest represents a total failure of not one but up to two years investment. It is a catastrophe to the adults, and may well make them move site.
If a delicate Cain and Abel rescue is made then one takes a chick that would otherwise die when it is aged only a few days. It demands well orchestrated teamwork with months of close watch, hides, an intrepid climber or two, incubator/brooder, 24 hour care, precise diet and foster parenting. Crowned Eagles in our latitude rarely have 2 eggs, and siblicide is therefore an unusual occurrence. I believe chicks have been taken by this method in Zimbabwe and South Africa, but I would doubt it being the method adopted in Tanzania or Uganda. There is of course the absolute certainty of human imprinting the day old chick so removed, unless one happens to have a captive pair of foster Crowned Eagles under which it can be raised.
A human imprint Crowned Eagle is never likely to breed (except by Artificial Insemination) and be a danger to people and is a lost member to its own species. There really cannot be much justification for having such an eagle.
I have never understood the need for exotic raptors in zoo, aviculture or falconry collections and think it unethical. I believe that the main rationale is not conservation but either egotistical or financial. The bigger and more complete the collection, the more kudos or visitors. I have argued aggressively against exotic species being used in falconry to the bewilderment of many, who think only in terms of sustainability.
I do see merit only in real conservation arguments that outweigh the loss of the birds from their home country. These could be life saving for the individual bird, treatment, captive breeding for re-introduction, or saving a species in captivity when its wild habitat is defunct. If there comes a time when captive breeding for re-introduction is deemed an option Africa certainly has the proven capability of doing it themselves. However permission is seldom if ever granted for domestic use, but readily granted for export.

Importers could and do argue that they need the birds for captive breeding, as if captive breeding is a panacea of its own. But I know of not one single incidence of an exotic raptor benefitting from this exercise. (Except for bonafide work by established conservation groups for E.G. for the Mauritius Kestrel). Should the breeder have a plan to export the progeny produced to augment our impoverished populations then that could be considered as an option. But no, the export of raptors from Africa is a one way ticket to oblivion from which nothing returns.

Tanzania is one of the few countries with a well established wildlife export trade and large eagles as well as the Crowned Eagle appear not infrequently as subjects for export. In theory, a legal harvest is dependent on a scientifically substantiated population estimate from which one can calculate a ‘take-off’ quota. No-body knows the sustainable harvest quota for Crowned Eagles and no-one knows the numbers in Tanzania, so it should be inappropriate to entertain export, but it happens in spite of pleas to reconsider. From its slow reproductive recruitment and slow maturation one would immediately impose a precautionary approach to their harvest, but this is not understood showing an absence of consideration for their unique biology.
Neil Baker’s invaluable compilation of data for the Tanzanian Bird Atlas has numerous advantages over Kenya in being contemporary and reliant on a larger informant network. From his work it appears that the Crowned Eagle is patchily distributed and nationally sufficiently rare to support a no export policy. The pattern of occurrence, density, threats and problems are not dissimilar to Kenya, but if one would include ‘export’ as a threat it has one more additional problem to contend with.
It is ironic that I have spent much time and money breeding and releasing captive bred Crowned Eagles on the border with Tanzania, to have the Tanzanians legally capture and export the very same species. It is poignant to note that I had painful bureaucratic hurdles to leap and still suffer from critics who disapproved of the release programme yet CITES and IUCN make it much easier to ship them out to zoos for profit. On one side of a border we consider such augmentation a worthy exercise, requiring at one time the full back up of KWS, volunteers, Finch Hattons Lodge, a project vehicle, a home -made aircraft, radio telemetry and running expenses. To have on the other side of the border a few kilometres away, someone ship them out to die overseas.
When we are asked on the raptor network to make a comment regarding a raptor species destined for export, we are obliged to remain unemotive and respectful of the country’s policies. Casting sentiments aside it is still extremely difficult to understand why one should export (or import) Crowned Eagles. Africa certainly exports raptors on license and with CITES permission, but there is no evidence to say that this exercise in any way benefits the wild resource. There is every indication to say that it harms it and every ethical perspective to say that it is wrong. Money is the only objective as there is no local conservation related obligation demonstrated by the receiver. I question the ethics of the importing country and individuals behind capturing Crowned Eagles for raptor exhibits in Europe, USA or Thailand (see Youtube for the latter!). There are a number of falconry trained Crowned Eagles in Britain and one even in Scotland, where Golden Eagles would be much better suited. If Crowned Eagles were common and stable, I still see no ethical reason why they should be harvested and exported. If the importer makes any claim that they are supporting conservation they have yet to demonstrate it. If some argue that they have secured the species future, albeit outside their doomed range, they have yet to propose any action to support a programme to achieve this objective.

Juvenile Crowned Eagle, © Simon Thomsett

Future predictions for forest species

Recently I listened to Don Turner giving a talk on the status of birds in Kenya. He is a world renowned ornithologist and author with a precise analytical mind and spans pre and post colonial Kenya. He talked of the big picture, of global warming and of Kenya’s invigorated complacency and emerging lack of accountability for what we too happily assume to be only a western evil. Namely, Global Warming. (Africa burns the size of Australia each year, without guilt for carbon emissions, for EG.). Don spoke of Kenya, its 5.5 million inhabitants in 1955, and its over 41 million (published) today, showing little sign of abating and doubling in less than 15 years or so. That’s 20 million below 15 years old. (Even government admit to 71 million by 2030.NB. 4-6 times growth by 2100). UNEP had once calculated a maximum holding capacity for Kenya at 22 million, and we’ve doubled it already. It takes less than 3 years for us to add the same population it took humanity more than 3 million years to achieve by 1955. He then listed those bird species that have gone extinct, those that have not been recorded for many years and those we know will go extinct. Not surprisingly these were mostly forest birds. (NB. The only raptor to be officially extinct in Kenya is the other forest eagle; the Cassin’s Hawk Eagle). His frustration was evident and when questions came the unanimous consensus was that Kenyan conservation organisations and all the associated NGOs had failed shamefully at even raising the matter of “OVER POPULATION” and “UNSUSTAINABLE” land use practises and the devastating effect it has on our bio-diversity (ESPECIALLY FORESTS). All agreed the systems in place to evaluate threatened animals were disgracefully deficient. I thought his lecture refreshing because it did not sugar-coat the facts and moreover, was totally accepted by an entirely Kenyan audience. This audience had no ‘politically correct’ agenda and no hang-ups about putting the blame where it is due. I have to add than even in my most pessimistic mood the outlook was much worse than I had assumed. While a critic, I had also been subconsciously deluded by the current status evaluations persistently voiced by large NGOs. Perhaps I too have been successfully duped by KWS branding propaganda and national zeal that sells Kenya as a success. We all felt deceived and let down. The implications were clearly that we were facing a catastrophic unparalleled loss of forest species and bio-diversity and that there were no functioning actions in place that would mitigate these losses. This conclusion was applicable to all countries in Africa with similar human demographics and policies. It was probably worse in those countries considered unstable.

Two kinds of Crowned Eagles

Many authors have recognised the distinct difference in prey selection between Crowned Eagles living in forests and savannah biomes. Leslie Brown in Kenya, as well as observers in South Africa (Boshoff, A.F., Palmer, N.G., Vernon, C.J., Avery, G., Jarvis, M.J.F., Symes. C.T., Raath. A.) all noted a shift away from monkeys when living in “bush” environments and a shift in hyrax and antelope species. However these forests hardly compare to those of the central and west African types, and differ so markedly in species abundance and prey species ecology, height, quality and extent as to be incomparable.
These populations under study often occurred adjacently or within a small area sufficient for none to assume any real difference in the birds, only their prey. While I suspect that there are physiological and behavioural differences that define these two groups at the extremes of their occurrence it helps in estimating their status if they are so separated. Crowned Eagles are ‘true’ forest eagles apparently (thanks to recent DNA work) more closely related to old world Hawk Eagles than to any other. But the Crowned Eagle has been isolated from its closest relations long enough to have evolved independently and be unique in being that much larger and more powerful. (It is one reason why ‘hawk’ in Crowned Hawk Eagle has been dropped). It has the classic accipitrine body build with short wings, long tail configuration, the harpy-like facial ruff and crest, the deep brutish eyebrows (protection against violent collisions against brush), and a nervous disposition so similar to accipiters. These all support its forest roots. Perhaps monkey predation did originally drive its evolution by increasing its size and foot structure. The tarsus has tall ridges that run its length separating massive tendons and increasing the strength of the bone. The twist, said to offer a dynamic shock absorbing rotation is hard to understand, but certainly sets them apart in an area where raptors need it the most. All in all it is a surprisingly well designed eagle despite its somewhat primitive Neanderthal looks.
Despite having a typical forest adapted ‘flight envelope’ it does not oblige them to a life confined within closed canopy, but significantly they do use it to the exclusion of other large eagles and they almost certainly evolved within it. The other large eagles cannot penetrate their forest realm, but when the Crowned Eagle exits the forests they share their foraging ranges. Their evolutionary home would appear to be dense tall forests, and from that it has cautiously ventured out to less dense more open habitats. These eagles can be split into ‘Forest’ and ‘Bush’ eagles. While an artificial partitioning it is deserved, and needed for their evaluation.

The ‘forest’ eagle.

The supermarket of food in the African primary forests is mostly monkeys. A staggering 350 to 558 individual monkeys per square km is possible in these tropical forests providing an easy to see, if difficult to kill, food source. Killing monkeys needs two things, suitable weapons and strategy.
Of avian competitors in forests it has none. The Cassin’s Hawk Eagle is to all intense and purpose a thick-set Ayres’s Hawk Eagle or forest adapted African Hawk Eagle, certainly not a true Spizaetus Hawk Eagle or smaller direct relation to the Crowned Eagle. Its prey range barely overlaps (large squirrels) and it is not a serious competitor for food and an inconsequential problem with regard to nest sites. Monkeys are tough and have long limbs with powerful hands that grip and huge canines to bite. Very few eagles, even the (previously termed) Philippine “Monkey Eating” Eagle, or the Harpy Eagle prefer monkeys. While ‘bush’ eagles have much less monkeys on their menu, ‘forest’ eagle life revolves around them. The ‘forest’ eagle is numerically the most abundant and probably the most important medium sized carnivore in these forests, devouring the most amount of meat. Given their combined numbers, prey range and physical daily nutritional needs they consume more than any single predator such as the Leopard or Golden Cat. These forests are typically devoid of canid hunters/scavengers, hyenas, or terrestrial predators. The way things work in these forests is different from what we in savannah Africa are familiar. Here in the forest the Crowned Eagle is King, whereas the ‘bush’ eagle is not.

A titivating recent hypothesis is that a distant ancestor of the forest dwelling Crowned Eagle moulded and shaped the early monkeys. The “taphonomic” implications of Crowned Eagle predation on hominid evolution makes for compulsive reading. I have little idea what “taphomology” is all about but have no doubt it adds some credibility to whether Crowned Eagles moulded slow, small, daft arboreal proto monkeys into US? Alarms voiced by those early monkeys at seeing their main predator became complex and led to communication, group cohesion and delegated roles in their community. Even their physical agility and vision could, in part, be related to those pressures placed upon its evolution by an avian predator. An active arboreal life for an animal weighing over a couple of kilos is a diurnal one, for leaping into space on distal tips of branches in darkness would lead to an early demise, as gravity, darkness and weight are a bad combination. A larger body mass would therefore make you diurnal and vulnerable. You have to be smart and small but then a much larger body mass would make you less vulnerable as well. Predation by the ancient Crowned Eagle was most likely the pressing factor that increased primate body size as a way to beat predation. It came at the great cost of loosing access to the most nutritious distal leafy parts of trees. Some of the heavier monkeys descending to the barren, least productive forest floor and this obliged them to eat invertebrates and meat and predate. This created an omnivore with a smaller gut that also allowed quick bipedal movement, more time on its hands and the essential nutritional building blocks for a larger brain. Perhaps then as is true now, terrestrial predators in forests were few, but they would still retain an ability to climb trees as we do today. Perhaps the early proto Crowned Eagle could see the writing on the wall for it seems that one did its best in squeezing the life out of the Taung australopithecine child. That the Crowned Eagle is the only confirmed ‘juvenile man eating’ eagle today makes it highly likely that it was at one time a real threat to smaller early hominids juveniles. Sadly for the eagle, it may have contributed in transforming a tree dwelling small primate into us. Predation is a persuasive reason to evolve, and when one thinks about it no other predator could have been as important to early medium sized primates. I’d like to see one of those artist representations of early man evolution with each figure looking skyward waving a stick and hollering “watch out” in lesser and lesser degrees of intensity.
If this theory had any merit then why is it that the Harpy Eagle didn’t round up those backward new world monkeys and make those into terrestrial giants with brains? The Harpy’s main food is sloths so why in heck didn’t those evolve into huge beasts that had to descend to the forest floor. Oh, hang on, maybe they did, and we bumped them off.
Sometimes after having seen a truly monumental kill made by this medium sized eagle I shudder at just how life threatening they would be if they weighed only 2 to 3kg more. A Crowned Eagle weighing 12 to 18 lbs would be well within the weight range and flight envelope of a Harpy or Steller’s Sea Eagle. But it would be terrifyingly capable of killing humans. If it weighed say 25 to 30lb (such as the Haast’s Eagle of New Zealand), it would probably specialise in humans. I suspect many such ‘hazardous to human life large eagles’ were killed off by man, and you have to wonder if somewhere in the sub fossil strata of Africa’s rain forests such an eagle remains to be found.

I learned an enormous amount about the ‘true’ ‘forest’ eagles from Dr Susanne Shultz when I was asked to go to Tai Forest in Cote d’Ivoire for the Peregrine Fund to catch some of her study birds. I learned much too from simply looking around me in an environment, though tangibly similar, wholly alien. I found those ‘forest’ eagles as different and incomprehensible as a foreigner. They just were not the same as the ones in East Africa. One species can behave differently depending upon its environment and the distance between them. I was able to handle these eagles and compare them to the Kenyan variety and I did note subtle differences. And why not, for these eagles have been as separated from each other as have the Forest from the Savannah Elephants. I found them smaller but as large footed, thuggish in build with deeper eyebrows, noisy and pugnacious in character. I’d like to call them S. c. troglodytes ! Sadly these subtleties in structure are hardly quantifiable and unlikely to galvanise the ornithological taxonomists into desk-pounding proclamations of agreement.
One important thought occurred to me as I walked out across a broad lateral branch high above a green carpet of lower canopy trees in Tai, was the three dimensional extent of these forests, compared to those used by ‘bush’ eagles. One doesn’t have to sit through the agonisingly predicable “Avatar” movie to get a hang of what I am trying to describe, but it would help. It would help too if you saw it with 3D glasses, and not a pirated version on your laptop. The ‘forest’ eagle group lives in high, multi-layered canopy wet forests. The usable foraging area must consider these forests in terms of total surface area in the vertical aspect.
These horizontal multi-storied canopies and tangles of vertical growth harbour a whole world of epiphyte fauna from large to tiny sun and flying squirrels, tree mice, Pottos, galagos, Palm Civets, hyrax, a multitude of birds, tree pangolins, dormice, lizards, reptiles, hornbills and an unequalled array of monkeys. Literally tons of animals live in the trees and seldom descend. From the top canopy you look down upon the feeding animals, themselves high up on the tops of trees. On the ground surface dwell the mixed groups of Duikers, Suni, Bushbuck, Chevrotains, Liberian Mongoose, Cusimanse, Monitors, Dwarf Crocodiles, Bush pigs, Forest Guineafowl, Congo Peacock and Mangabeys. One underappreciated habitat is the tree buttress bases, limb falls, vine tangled glades, leaf litter and the upheaval of root structures that has no resemblance to tera firma, but to mouldy cheddar cheese. The terrestrial and arboreal species move together like gigantic communes. Food, fruit, rejects, faeces and litter is dropped from above and consumed below. Just as small bird feeding parties move together so do these and in so doing they move in and out of territories of Crowned Eagle pairs. These eagles must hit these parties as they pass through the neighbourhood like kids chasing an Ice Cream van. In other words there is a time of plenty followed by paucity and there must be plenty of territory infringements and disputes. As a result Crowned Eagle behaviour must to cater for this.

Here the monkeys alone amount to a weight of meat biomass available to Crowned Eagles in access of the meat found in the migrant ungulate ecosystem of the Serengeti. Little wonder that Crowned Eagle densities can be very high at 1 pair per 6.5km2 given that prey density! That’s less than 1.5km between each nest….a veritable colony of breeding eagles! But their actual foraging range is multiplied by the surface area that the multi-tiered canopy and vertical surfaces provide. One cannot compare the number of potential victims a serial killer stalks in a 5 sq/km quadrant of sky-scrapers in Manhattan as opposed to a similar size in single storied suburbia. In other words the actual surface area available to a forest eagle may be at least 3 times the 6.5km2 (some 20km2). The amount of suitable prey available is open to conjecture, but it is much more than in any other environment.
While there is a staggering supply of prey it isn’t as one may assume (for tropical forests) a steady and guaranteed uninterrupted year-round food supply. One aspect of possibly crucial importance to Crowned Eagle biology is the need for most of their prey species to forage together and move to seasonal fruiting trees. They move in noisy close-knit groups as much for detecting food as for mutual protection from Crowned Eagles. Although eagle territories can be small in these super-productive forests they may be more fiercely defended. I’d doubt any relaxing of boundaries for intruding eagles bent on following these feeding groups within neighbouring territories is permitted. Feeding groups of prey species must wander outside of a pair’s foraging range and thus often leave pairs with little prey, while other pairs have over-abundance. When the monkeys and duikers have left an eagle’s “patch” they must either rely on reserves or be able to kill larger or smaller-than-usual prey species that are left behind. They must have strategies that keep them from going hungry. I believe that their hording or “caching” ability may be one very well developed habit not entirely perfected to the same degree by any other eagle. This caching may help them through the expected time of paucity as well as be a more efficient use of hard-gained and large food. The dissection and transport of limbs, nearly innate even in captive bred Crowned Eagles, is only practical for large prey. I am unsure if any other large eagle has this habit. It also hints at some intelligence and forethought. One macabre anecdote is that while investigating an alleged kill of a human infant (4 year old girl) I was brought to the tree where her severed limb was found. The circumstances led to no doubt that the accusation was true for no leopard could have climbed that tree, and nor did the locals know that eagles cached limbs.
One plausible survival strategy when things look bleak is to hunt prey outside the normal prey range. I once found a trained male Crowned Eagle, left out for the night on a freshly killed dove early the next morning, and I have also flown other males at spurfowl and guineafowl with some success. Small males in particular can hunt birds quite frequently, and I knew of a pair in Mweiga that frequently took Kenya Crested Guineafowl and Leslie Brown once found a fresh Marabou Stork! Apart from birds they can also kill very large prey.
The Crowned Eagle would seem to be overly well-endowed with massive killing feet. None can talk of this eagle without reference to its extraordinary power and ability that, if it so wished, can kill animals 10 times its own body weight. If in doubt, Youtube the less powerful Golden Eagles killing Wolves and you’ll get confirmation that eagles can kill very large animals if they have to. The desperate hungry young of most raptors (both wild and captive) are reckless and capable of extraordinary feats of strength. One must put to bed the oft-repeated notion that eagles cannot kill very large prey even though it does not do them any favour amongst sheep farmers! Acknowledging that they can, opens up an intriguing debate as to why they do, but do so rarely. On occasion a Crowned Eagle can step into the mega-carnivore niche and this should surely have a survival benefit for when usual prey is temporarily unavailable? Larger forest animals such as large duiker and bushbuck may have less need to eat nutritious fruiting foods and thus are more sedentary and stay within confined territories. These species can be found alone and not be dependent on sentinels. In high latitude parts of the world when food is suddenly made scarce due to hibernation, snow, inclement weather or migration, food deprivation can drive an eagle to kill much larger prey. The seldom used reserve of immense power has an easily understood survival benefit in these circumstances. It does have its dangers of course in their being injured or exhausted to collapse. But it is an important, intriguing and yet curiously neglected part of many raptors’ biology.

Crowned Eagle nest, © David Gulden

The status of ‘forest’ eagles can be made by quantifying the square kilometres of land under primary forest, and by subtracting most of those forests that have been poached out for bush meat. For an eagle it historically must have been surprisingly abundant, but few would argue that good quality forests with prey is anything other than a rarity and under severe threat. From a status point of view the ‘forest’ eagle occurs in those rapidly dwindling, formerly vast tropical rain forests of West and Central Africa. We can make fairly good guesses at their rate of loss if we know the rate of loss of these forests and their prey. Unbiased interpretation of satellite imagery should give one a good estimation.

The ‘Bush’ Eagle
‘Bush’ eagles are those that have ventured out of the wet jungles and colonised dry forests, moist central African-type isolated remnants, riparian and open highland woodlands from Ethiopia, southern Sudan, throughout Eastern Africa and down through the miombo belt to Southern Africa. In East Africa many forest patches were found clinging to the tops of isolated hills and mountains, and on inspection almost invariably had one pair of Crowned Eagles. These forests, respected by law and custom survived up until the late 1970’s when the human population seemed to tip the balance and lead to a country-wide loss of quality and extent of this eco-type. I believe it quite feasible to state that if a country has a certain human population density, some species can survive, but add on a few more million and they cannot. Those forest patches exceeded that threshold 30 years ago when we had less than half the human population.
Their day to day life, prey base, food security, hunting methods and competitors are different to the ‘forest’ eagle. I have watched soaring ‘bush’ eagles high above a thin riparian forest launch a successful attack against young warthogs feeding out in a dry desolate treeless plain. The flight, attack and location was atypical of the species, but it did not look out of place at all. These eagles hunt open area species small ‘plains game’ ungulates, carnivores, mustelids, viverids, primates, rock hyrax, hares (even Springhares) and so differ from the ‘forest’ eagles.
I was lucky to have sat with Leslie Brown looking out across the tiny forest patches of Ololua and Eagle Hill looking at his famous eagles and hear him speak of the changing menu of those pairs as forest prey species were lost and replaced by more open savanna species. Their adaptability within their own lifetime was impressive, with the Ololua pair changing its diet from diurnal Suni, duikers, monkeys and hyrax to nocturnal genets, mongoose, greater and lesser Galagos and hyrax in the 1980s. The change was forced upon them as poaching and disturbance obliterated the diurnal species. Notably they struggled to breed successfully for a decade before becoming only an occasional and non-breeding visitor. A change in diet such as this may be a pre-emptor to loss. These scrounging desperate eagles are picking the bottom of the barrel and Crowned Eagles that utilise unusual, domestic or nocturnal animals should not be thought of as successful.
These ‘bush’ eagles closest neighbours are not usually their own species, but other large eagles with some prey overlap. Aggressive encounters with their own are less likely but they must compete for space, food and sometimes nesting sites with other species such as Martial, Verreaux’s, Tawny and African Hawk Eagles and thus lose their monopoly. Having other species as immediate neighbours may help buffer encounters with other Crowned Eagle pairs who live the next street over.
The ‘bush’ Crowned Eagle’s distribution is not straight forward to predict. In Eagle Hill near Embu the famous Crowned Eagles lived in an area of some 10sq/km of forest patches interspersed with rocky out-crops and low thicket-clad hillsides. But other similar neighbouring hills, larger and as attractive did not have a pair. The wooded hillsides formerly so typical of mountains, rift escarpments and hills throughout Kenya were certainly likely to have pairs up until the mid 1970s, but it would be hard to estimate exactly how many without each being checked. Because each pair owned a forest patch and were separated from the next forest patch (10km to 40km) it was not possible to estimate density in terms of 1pair/??km2 in the same manner as those ‘forest eagles’ in contiguous forest. The Eagle Hill pair were alone throughout Leslie Brown’s 378sq/km study area during the 1970s for example, but that is not to say there is 1pr/378km2. The nearest pair I knew of was some 50km distant making the density 1pr/2500km2, or not. From a satellite photo these isolated and small locations would be tough to predict as Crowned Eagle habitat and one would be seriously led astray if one persisted in establishing a density figure for this habitat.
In contiguous forest Leslie Brown thought nests were separated in Kenya by 15km, and this may have held true in our highland forest where biomass is less abundant. I encountered 4 nests some 5 to 6km apart in the Aberdare’s Salient, but worried about being so bold as to make a density estimate. For one thing, each nest tended to be in a valley and pairs would utilise that valley in long winding corridors. In the adjacent valley, over the ridge another pair would operate 5 to 6km distant. While nests may have been close, actual territory use was linear or wedge shaped and separable by ridges. Short of radio telemetry work establishing territory size in East African fragmented forests is tough. Because of “edge effect” particularly where park boundaries meet densely populated rural farmland communities with small livestock, I suspect that nesting sites and territories require a buffer of at least 2km. But in more tolerant areas without high level of persecution they can nest within (see Ololua forest pair in ‘Urban Eagles’), some 100m of human habitation.

It could be supposed that a population that lives in drier less productive areas would have less biomass available and less density. Within these restraints ‘bush’ eagles, particularly at higher latitudes would be expected to reproduce less, mature slower, live longer and have heavier body weights. Perhaps they do.
The status of the ‘extralimital’ ‘bush’ eagle population is probably as important as the forest eagles, if not so dense, it is wide spread. However statistics on the presence or removal of suitable small forest and woodland habitat across this region is worse than that of the rain forests, as it is not seen as an eco-logical crisis worthy of investigation. Dry woodland loss is deemed less noteworthy of international concern, difficult to qualify and quantify on satellite imagery and frustratingly difficult to assert as suitable for Crowned Eagles. Leslie Brown used to wonder why it was that seemingly less suitable sites would have many eagles, yet others larger, and to us, better sites did not have nearly as much. It is therefore not very easy making accurate judgement of a forest from afar, and footwork is required.

The urban Eagle
No summary of the Crowned Eagle would be complete without reference to their ability to nest within very close proximity of sub-urban humanity. In Kenya the famous Ololua pair that nested within sight of Leslie Brown’s office window in Karen was testimony to their tenacity. That same site was known to the Bursell family back in the 1930s, and it survived regularly producing young until the late 1980s. It was one of the last pairs to go from a list of 23 known to me. Nesting activity ceased in 1994 and by 2005 Crowned Eagles were very rarely heard or observed in the area. An adjacent pair nested on a Cape Olive only 120m from the road I used to take to school. The site was within Nairobi National Park, but they must have used residential suburbia to hunt. Today that pair seems to have moved 500m to a small eucalyptus plantation, incongruously still within the park’s boundary but adjacent to a main road. Yet another adjacent pair nest in a croton in a newly formed sanctuary near a mortuary, racecourse and show ground. I recall incidences of direct persecution of these eagles, one shot by the secretary to the Elsa Trust, another shot for eating Burmese cats, another shot in Mwitu Estate for again eating cats. These individuals, despite an educated upbringing and very aware of conservation issues epitomise the NIMBY (Not In My Back Yard) sector, that is all too prevalent in Kenya.
In Durban such a pretty scene is repeated. Pairs nest in river gorges that have on either bank a suburban setting. Pairs nest elsewhere not in protected indigenous forest parks but in forests sometimes dominated by plantations of exotics.
These pairs have one thing in common seldom if ever encountered elsewhere. These territories lie within the affluent, well educated elite communities who raise Swarovski binoculars at them, not (usually) shotguns. It is absurd to assume that this pattern of occurrence is replicated anywhere else where no such veneration will excuse the eagles of their depredation of livestock or bush meat.
The forests near Nairobi have governance and protection seldom afforded any other forest (other than those protected in well managed national parks). There was for example dead timber on the forest floor, suni droppings, minimal livestock, minimal snaring and low human disturbance. Whereas other forests, far from the capital city, even in much less populous areas have as a rule a rural community to sustain with firewood, livestock grazing and other natural harvestable produce collection. Incidentally those pairs in suburban Nairobi forests are by no means secure and are probably under immense stress and should not be held as examples of the success of the species.
Previous to the aforementioned gum tree nesting pair I never knew or heard of these eagles using anything other than old mature dominate native trees within native forests. I recalled seeing gum tree leaves in a nest near Mweiga in 1978-79, and speculated then if they knew the insecticidal properties of this (then locally) tough to find exotic. Crowned Eagles will of course use eucalyptus and other exotic trees to perch in wherever these trees mingle with indigenous forests or bush. For the vast majority of plantation exotics in Kenya they are all characterised by sterility and as much biodiversity as a wheat field. These exotic forests have not had the time to stabilise and slowly allow habitation by enterprising wildlife pioneer settlers. Again these exotic forests support rural communities on their fringes and within their core who disturb the forests and probably keep such pioneer species out. I hear for example, that the Red breasted Sparrowhawk is very much at home in exotic plantations in South Africa, whereas in Kenya is has yet to be recorded in anything other than indigenous and now rare type of highland forests.

I feel privileged to introduce someone who is so dear to me. I hold him on par with my childhood

I first met Simon nearly twenty years ago when he was on the look out for a Kenyan student to train as a raptor biologist. Currently a Research Associate at the National Museums of Kenya, The Peregrine Fund had taken him under their wing to help revamp raptor studies in the East African region. “Turn up at my ranch tomorrow, ” he said, when I met him briefly at the museum offices in Nairobi. Blonde hair, blue-eyed with rugged looks, almost like a younger version of Harrison Ford, Simon sauntered away down the staircase as I watched wide-eyed. And then, almost immediately, he reappeared. “Ah, you will need directions, he said. “Go down the Mombasa Road until you get to Lukenya Hill, turn right at Daystar and go exactly seven kilometers where you will see a Martial’s nest on your right. Exactly opposite is a gate with a padlock – key under rock”. I turned up the following day to begin my adventures with Simon.
When I turned up at his place, he looked at me from top to bottom, suddenly bolted out in the garden to peer in the skies above, returned and said almost nonchantly “Cuppa tea?” Within an hour, he had introduced me to a world of raptors that I never knew existed. He exuded passion and charisma – I stood there in awe, hypnotized by his tremendous wealth of knowledge but more so, his affection and fondness for his raptors. An accomplished falconer, Simon has lived a charmed life having had his first Lanner Falcon at the age of six. He grew up spending days on end in the wilderness areas of Kenya hunting with falcons and spending time in the back of their family car whilst his father filmed Africa’s big cats. Simon’s greatest love has been his two legendary Crowned Eagles – Rosy and Girl, both of whom he looked after for over 35 years, and I am happy to add are still by his side even today. Simon’s love and knowledge about raptors stems from spending time in the field with his mentors – Grahame Dangerfield and the late Dr Leslie Brown, both legends in the field of raptors. Other people who have had tremendous influence in Simon’s life have been Peter Davey, Cunningham van Someren, David Hopcraft, Tom Cade and Leon Bennun (all incredibly talented and unique individuals). Simon has the most amazing ability to absorb information, process it and come up with his own unique ideas and hypotheses. “Why can’t we introduce Long-tailed Hawks in Kakamega Forest?” he would tell me.

Simon has imparted his knowledge and skills to tens of thousands of individuals. From children of Kenya’s rural schools to affluent Hollywood film stars, he has touched the lives of many. When Simon speaks, people listen in awe and great admiration. His energy is infectious and addictive. He has helped students selflessly – from the rainforests of Madagascar, to the thick forests of Ivory Coast, where he dangled from trees to help trap and band Crowned Eagles. His experience was critical for some of The Peregrine Fund’s projects in places like the Cape Verde Islands and in Ethiopia where he single-handedly scaled 300 m cliffs to search for Bearded Vulture chicks for a reintroduction program in Kenya. For me, the greatest moments would have to be spending time with him in the field where he was at his element. From wrestling vultures in the savannahs of the Masai Mara, to crawling through the dense fluorescent-fungi understory of Arabuko-Sokoke Forest and Ngezi Forest in search of owls, to the dense jungles in Bandhavgarh National Park, India, sitting with Simon around a crackling campfire sipping tea and listening to Simon stories would have to rate as magical.

Cats are believed to have nine lives, but Simon has at least nine hundred – which include surviving from crashing in a home built plane to having a one ton water tank fall on him. But those stories are for another day. For now, prepare to be inspired and motivated by Simon’s interview about his much-loved Crowned Eagles.

Munir Virani

Simon Thomsett with Crowned Eagle

A long while ago I was asked by Markus Jais and Munir Virani to contribute to an interview for the Africa raptor network on the Crowned Eagle. The species then pitched up for discussion in the raptor network due to a renewed request for permission to export two birds for breeding from Tanzania to UK. That incensed me and I ended up skewing this interview towards status. Then I went walkabout without internet connection and now finally have chance to revisit it.
It was an honour and a great chance to be self-opinionated and long-winded about my favourite species. Thanks! Of the species accounts I was able only to read Rob Davies excellent Verreaux’s Eagle interview and envied him his clarity, experience, humour and especially brevity. I have one point to add which will sadden Rob, of their status in Kenya. It may be best illustrated to him by casting his memory back to a line of cliffs behind the famous Ngong Hills to which he and I went trapping Lanners sometime in the mid 1980s. Those Verreaux’s Eagles died out around then, as did the Egyptian Vultures. The eagle pair written about by Karen Blixen on the Ngong Hills themselves, preceded this pair by a few years, and some adjacent pairs throughout the valley towards Suswa died out shortly thereafter. Leslie Brown’s pair on Eagle Hill Embu were lost in the early 1980s. That makes about 75% of all Verreaux’s I knew of back then lost in that decade. It is a recurrent theme as will be seen below. While there are rare exceptions only those nesting on vast, untouchable cliffs far from the usual “shamba” systems of rural and pastoral humanity stand a chance. Kenya underwent a period of dramatic wildlife loss and ecological instability and despite the Verreaux’s Eagle’s tenacity in South Africa and its predicted ability to out-survive all other of Africa’s large eagles, I would unhesitatingly up-list it (for our region).

While in his day, Leslie Brown considered the Crowned Eagle to be one of the worlds’ best known eagles it is a sad thing to note that there are simply not the resources today to state the same for contemporary Africa. Although the last 50 years has been characterised by a decline in observers, expeditions, collectors, and naturalists across most of the Crowned Eagle’s range a number of researchers such as Drs Susanne Shultz in Ivory Coast, T. Struhsaker, M. Leakey and J. Skorupa in S. West Uganda have added crucial insights to their biology from regions otherwise largely ignored. Studying the Crowned Eagle above the Tropic of Capricorn, west of ‘dry’ East Africa, they are seeing the species outside of its oft-studied and possibly peripheral distribution in East and Southern Africa. That raptor research and awareness has increased in Southern Africa over the same period may show a discrepancy of knowledge and opinion leaning towards that region. A status review should apply to the whole and not a small part within it and it should be ever more frequently evaluated given the exponential growth of problems it faces across most of its distribution.

Magu April 2005, © Simon Thomsett

I am acutely aware of the danger of summarising global status by referring to one’s own knowledge of a small part of their distribution. For example, I live in what is widely perceived as one of Africa’s most ‘successful’ countries with functioning wildlife policies; acknowledged as a rare thing across the continent. Therefore basing one’s judgment on this small area could lead to a bias towards making a too rosy a picture for the rest of Africa. But as I once knew of some 27 nests/territories in the late 1970s that plummeted to just 3 in the following decade and none in the next, I realise that Kenya may represent a confusing paradox. While the country is sold as the secure wildlife destination for tourists, those less easily duped by this national commercialism often seem seized by equally dramatising an opposing view. They believe that most large species of wildlife have declined at such high rate that the sheer kinesis of their descent will see them to extinction (locally). Exponents at each end of these extreme views may benefit financially or theatrically from their position. Others especially in administration, bumble along somewhere in the middle, enjoying a status quo and shaking their heads at extreme views. They hold court and demand substantiation, raising or lowering the bar if a matter gets awkwardly close to having to do something. If, as may be the case, Kenya as a nation is inexorably sinking gently into the Indian Ocean with one hand on the lavatory plunger and the other waving frantically for help, the world will look away. From their offices in Switzerland will come the stern reminder that the species occurs elsewhere.

In the conservation (and gargantuan humanitarian) businesses of our country it is essential to pronounce doom as well as success according to popularity ratings and funding opportunities. It may keep them in business, but it can obscure facts at a shameful scale and seriously impede wildlife conservation. Politics and corruption can interfere and thwart projects that rock the boat, identify culprits or suggest solutions; especially when it comes to forest conservation. It is in this emotionally manic and bewildering country of opposing opinions and ‘poor science’ that one, not surprisingly, finds a lack of reliable data and statistics on habitat and basic anthropomorphic factors that affects the environment. I for one have lost faith and dread to think what a hash someone could make if they honestly relied on what is printed or told “on good authority”. Predictions and future trends are notoriously divergent, so much so that the sum of it is an inability to state with confidence the status of most mega-fauna, let alone an eagle. It is wise to take all that one hears with a pinch of salt, seek alternative impartial reference and look for oneself.
It is best that one steps back, into a space ship preferably and looks down to see the continent from a holistic and wider perspective. The technology is there, for when we had one downed helicopter recently on the slopes of Mt Kenya we were able to access, by the hour, high resolution satellite images from the US military sufficient to see the wreckage, but apparently we remained unable to see, publish and act upon the vast swathes of cleared forests on that same mountain. Previously when evidence was collected the main financier was shot dead by his gate one evening in a random senseless attack, sufficient to lead to the early retirement of the chief investigator. If paranoia is allowed to creep in, one is free to imagine all sorts of intrigue and deceit regarding forest conservation in our part of the world.
Importantly for all wild fauna and flora assessments, that easiest to quantify and most important variable, the human population, is obscured. In 1991 an independent assessment by the Kenya Rangeland and Management Unit (KREMU) based on satellite imagery estimated a human population one third to twice that given by a contemporary government census. The tribal constituent and distribution of human populations is of crucial political importance. The human population must be seen to be within manageable limits otherwise World Bank and other loans will be tough to get. It takes a peculiar understanding of current affairs to see reason behind manipulating human population estimates. I am not alone in having little confidence in the human population figures published. Today when we discuss population we ask by whom it was published, and then nod or shake our heads while grunting sceptically or in acceptance. Somehow, somewhere politics and other interests do distort and censor what we know. Furthermore comes the unpopular task of shocking the citizenry that some 50% is below 15 years of age and we still have one of the highest population growths in the world, and that population still has a daily dependency on the natural things around them for food and fuel. To return to the 1970s subject of planned pregnancies and stable population is seen as an abomination of human rights these days. It is much better to ignore the whole thing and underestimate the truth and thus portray a wholesome future.
It is plausible that other countries have a similar corruption of data and I believe it to be the single-most limiting factor that discredits a science-literature-based approach to accessing species status across most of Africa. If we can’t agree on human numbers and differ as much as 25% to 50% in estimates, then we will be as inaccurate in our census of a species under review. Unfortunately for that species, that margin of error may make it either ‘Least Concern’ or Critically Endangered’.
Recent revised World Population Prospects (UN publication) predict that Kenya’s population will quadruple from 40 million to 160 million by 2100. If the current birth rate cannot be controlled it could reach 247 million. Uganda will be around 171 million and Tanzania will reach some 316 million. Given a demonstrated skew of data to lean towards an underestimate these predictions sound reasonable if not “optimistic”. Few would doubt that our current population with its land dependant lifestyle (even if it was stable), would need to annexe most protected areas, at some foreseeable point. 4 to 6 times that in less than 3 human generations would give one cause to doubt the survival for any natural resource, let alone a sensitive forest species.
Perhaps many, like myself are inhibited by answering the IUCN criteria regarding the status of African raptors. Staring incredulously with sinking heart at the myriad unanswerable questions I worry that in failing to satisfactorily oppose the most optimistic perspective will result in the species being tossed to the bottom of the heap as “least concern”. There I am sure, a number of Africa’s threatened species will remain while resources may be spent on less threatened and much better known European and North American species. If Africa gets a look in, it is often only a South African perspective that gets heard. One reason for this is understandable. There simply isn’t enough information regarding the rest of Africa and it is all questionable anyway.

Had I not had opportunity to travel widely in Africa thanks to work with the Peregrine Fund and a recent southern African trip with Laila Bahaa-el-din I would have remained insular and reserved enough to not dare pass comment on the status of a species across the whole continent.

Magu backlit, © Simon Thomsett

To try to answer status one could simplify it by examining three broad areas of concern; habitat, food, and mortality. The Crowned Eagle is a forest species with the lowest reproductive rate of all African raptors, competes with humans for “bush meat” and is persecuted over 90% of its range.
This brief and negative summary on those chief concerns should be alarming. But it is not, for a less gloomy outlook is voiced from a tiny area of its distribution. As a result of its South African status only, I believe, the Crowned Eagle is officially listed as “Least Concern”. This official choice of words is so deflating that it actively impedes work, research, funding and conservation direction as well as leaves one a little more than “vexed”. Unfortunately for a species so dismissed it takes, contrary to what you may think, a surprising amount of persuasion for it to be up-listed. Regional listings add an ambiguity that confuses the objective of the whole. While one must acknowledge that the status reviews are of good intent and a huge challenge, these status reviews are often so at odds with reality that it raises suspicion as to the accuracy of others. Despite the use of the CITES lists in designing conservation policies in , I can seldom justify using them in identifying species of concern.
What is more, I worry about those who do.
Besides, what does it matter if a species is “up listed”, or even moved up to the endangered species list? It may as well (as Neil Baker pointed out) be put “on the stock exchange”, for all that it is worth. Today advances in conservation are measured in changes in the syntax of documents, not in the field.
Expanding the argument, the Crowned Eagle’s main habitat is mostly wildlife rich, high canopy forest, the target of timber companies, agriculturists, palm oil and bio-fuel plantations, miners and slash and burn farmers. Africa has long been a drying continent with woodland and forest depletion (Sub-sahal Africa has witnessed human and livestock-induced woodland and forest loss and the advance of deserts hundreds of years before the new global warming scare). Forests have more direct methods of depletion. A charcoal-based economy outdoes minerals in Congo/Zaire, fuels wars, makes inroads deep into forests and is one of central Africa’s largest businesses with devastating effect on forests and wildlife. Closer to home charcoal taken from Kenya and Ethiopia finances the Somali warlords. This eagle’s main habitat is unquestionably in dire straights. The Red Colobus monkey, as species that typifies the optimal forest quality (and food species) for Crowned Eagles is singled out as one of the fastest declining and most endangered monkeys. Within the forest land-locked countries of Africa the bush-meat trade is the largest source of animal protein for humans. It is a multi billion dollar business with some 5 million tons (mostly small antelopes and monkeys… the Crowned Eagle’s staple diet) being killed each year. In just 500 million acres of the Congo Basin owned by 8 countries the weight equivalent to 40.7 million humans is removed each year (0r 740,000 bull elephants). That is fine if it is sustainable, but it is clearly not. The effect of this is to severely depress or remove the large, medium and small wildlife species of the forests. Crowned Eagles require some 430kg of “bush meat” a year and thus directly compete with the industry. The impact of this enterprise cannot be overstated for I have seen forests essentially devoid of wildlife in both East and West Africa. The demand drives poachers ever deeper and protected forests are by no means secure and most are not even monitored. Had I not witnessed it I could not possibly believe the impact of commercial small animal harvest and have had to change much of my thinking with respect to assuming that where there is habitat, there is wildlife.
In the bush meat trade the Crowned Eagle itself is shot and eaten whenever an opportunity presents itself and its feathers and body parts used as ornaments and/or for fletching arrows. In Cameroon for example poachers call them in by blowing on a cracked nut and then they shoot them. Direct persecution of the Crowned Eagle is not unusual and may be a major factor.
It is certainly known to compete with the bush meat hunter and not appreciated for killing small to medium sized livestock (chickens, cats, dogs, goats and sheep).
The feet of these eagles were once worn (Joy Adamson’s paintings of the 1950s) by witch doctors, and I have seen 2 pairs of feet, neatly arranged on the mantle-piece of a wealthy up-country Kenya house. I recently heard that eagle talons are sold to tourists on the beach as well as lion claws. While body parts are a curiosity it may be sufficient to mention it as a threat, but not at the same magnitude such as the parts of vultures in the Muti trade of South Africa.
Of feathers the following anecdote says much. I asked my night watchman to get some decent, more deadly arrows for his bow. He returned with some “good” ones from Kibwezi. On examination I saw they were fletched with Crowned Eagles. “Oh yes” said my night watchman of many years and one of the very few who has helped breed them, “That’s all we have left…you see there are no more vultures to fletch arrows these days. You could of course have had Marabou, but you specifically asked for “deadly” arrows. These, as you know are very potent and they are no good to us because they kill our goats!” Turned out I knew that pair of Crowned Eagles in Kibwezi, that were killed to fletch my arrows. They were the only pair for hundreds of sq/km. (NB. Nearly every rural household has security bows and arrows for the night watchmen).
It is likely that most Crowned Eagle nests and pairs within Kenya’s unprotected areas face direct persecution if a chance presents itself. Impunity for their killing goes without saying for no one has ever been charged or prosecuted for killing a raptor (except for one Bearded Vulture). Leslie Brown wrote of the difference in culture when he compared the forgiving nature of the Wambere in Embu (Kenya) with the game keeper attitude of those in England. He found it pleasant to note that while villagers would know of a particular eagle and its occasional depredations on livestock, they would leave the bird and its nest alone…whereas the western attitude (at that time) was to shoot it. I spanned that moment when this culture changed in Embu and saw the complete loss of all (but one species of 8 ) eagles within short order in the early 1980s. Gone are those days of tolerance and I blame in part new conservation policies that advertently instil the term “wildlife conflict” and create indignation (where none was previously) by offering sympathy and material reward. I copy the feeling that Leslie noted, in that increased awareness and western education removed the old customs, of tolerance and appreciation.
As the protected forest areas suffer from forest use (illegal or legal, it makes no difference) it is probable that virtually every Crowned Eagle pair faces a level of persecution that would be considered “unsustainable” within all but our most secure forested national Parks. Not all protected forests are good habitat. For example, Sokoke Forest National Park on the Kenya coast supports 1 pair of Crowned Eagles that took over a decade to locate and that tree and its neighbours were marked for illegal felling (in 2009). From what I have seen of the rest of Africa (except perhaps South Africa) the species is dependent upon conservation areas. Certainly its future outside of protected areas is unlikely unless it remains inaccessible and remote.

In Kenya we see a direct link between forest loss, human settlement schemes and untouchable businessmen/politicians benefiting from enormous land grabbing deals. It is the talk of the people, spurs armed conflict and national division and is the daily headline news of our newspapers but somewhat incredulously, still hopelessly lacking in sound statistics and prosecution. Civil disorder or war often vies for fertile forest land. E.G Rwanda’s Gishwati Forest estimated in 1986 at 100,000 hectares, and after the 1994 civil war only 600 hectares remained in 2001. A loss of 99.4% illustrates the ability of rural man to eradicate forests when forcefully or voluntarily translocated. Kenya’s civil disturbance of 2008 saw communities moved, some to forests. The Mau settlements and translocations are all manifestations of civil unrest and rapidly expanding human pressures copied through much of Africa, where fertile land is now rare. The Kenya Forest Service in response to recent national awareness regarding this forest loss aims to plant some 25 000 acres of forest per annum. But sadly these will be mostly commercial exotics an eco-type that in Kenya, has as much bio-diversity as a wheat field.

In the Cheranganis, said to be the least disturbed highland water catchment area in Kenya (and thus unrepresentative), Crowned Eagle pairs were widely persecuted during the mid 1980s when a wave of settlements occurred. Then estimated by WCMD/KWS and the local community to number in their “hundreds”, I plotted a possible 15 pairs. The area I covered was some 1/3rd of the total which is estimated at 1000sq/km2 and ‘protected’ under Dept of Forestry (I concluded therefore some 15pairs of eagles in 333km2 or 1pr/22km2). Amazingly some 605km2 of the total 1000sq/km was published to be under closed forest (2003), while I eyeballed it 18 years previously from ground and air as having not 60% forested but some 20%. Local knowledge of nests proved to be remarkably accurate and by cross referencing people around the perimeter up to 15km distant and following up on their directions I found they all converged on just 4 pairs (1pr/83km2), and concluded these to be close to the entire population within my 333sq/km transect (although I assumed the presence of at least 2 more pairs (1pr/55.5km2). Very low densities until one made the all too obvious conclusion that the forest cover estimated (E.g. by UNEP and BirdLife), was very much less and of much poorer quality than published. Cresting the edge of a hill and expecting (as had been published by UNEP from remote sensing) a vast forest ahead of me on Sodang Ridge I saw only farms, a shattered forest remnant and Erica heath. Kiptaberr forest said to be some 20,000 hectares and the largest was busily being hacked down in 1994 (the only area I have previously seen the Chestnut bellied Owlet), to a distant fragmented patchwork that today could perhaps house one or two harassed pairs of Crowned Eagles. (The emerging atoll hill and cliff also lost its Bearded Vulture pair around 1996, 0ne of only 3 pairs in the entire mountain range). The persecution level was 100%, for under every nest I was faced with outraged communities demanding compensation for livestock loses (Here, I trapped a female (called Girl) that killed a 4.5yr old girl in 1984.). I had to topple nests and translocate eagles. 4 active nests (out of 4 I climbed) had arrows sticking out of them and poisoned lambs were a known method used for killing eagles. One ingenious trap (used apparently for killing Bearded Vultures as well as vultures and eagles), was to build a small stone croft and cover the roof with poles and brush through which one tethers either a live goat kid or chicken or a dead animal. It took effort and patience to capture, by hand these eagles. There is little doubt that most if not all Crowned Eagle pairs in the “most secure water tower” in Kenya face a poor future and continue to survive in spite of the absence of tangible forest and wildlife protection.

There is one very important point with regard to this eagle’s habitat needs that is often misunderstood. I give an anecdote that greatly worried me. I was once called to task by an overseas ornithologist colleague attached to the National Museums who had just returned from a trip to the Taita Hills. He and museum staff had been mist-netting endemic birds and amongst other things had noted a nesting Crowned Eagle in a small 10 acre forest remnant surrounded by high density rural farmland. He then began to reassure me that Crowned Eagles obviously do very well in so small a plot and that my insistence that they could not was clearly emotive fabrication. There are some such instances of Crowned Eagles nesting in even smaller patches (Elgeyo Marakwet for EG), but there is an error if one happens upon a 2m wide mud pool and counts 50 cat fish, in assuming all is well. Obliged to retreat to a shrinking habitat, these eagles have to change their diet to suit what is available, and livestock is almost all they have to choose from. This is their last stand, and as surely as Custer they will not survive. I used to call eagles like these “ghosts” for they appear on our data sheets yet are not actual functioning entities. That these eagles can be that obstinate and yet still vanish illustrates the level of habitat loss and persecution needed to eradicate them. They are tough, tenuous and adaptable and they do not go easily. But they do go in the end once the land transformation is complete.

Crowned Eagle male, © Simon Thomsett

Of continent-wide generalised summary we are all familiar with reading National Geographic or international press reviews on Africa which note a general trend of environmental neglect, government corruption, a sell-out of natural resources (now China is proving to be the major concern), continent-wide growing lack of education, rampant poverty, escalating and unsustainable human population growth, hunger, civil war, desertification….etc. Significantly data from Africa regarding forest loss is the least known. But it has been stated that the Congo rainforest has had the highest rate of deforestation of any tropical region in the world. Somewhat staggeringly obvious, one new paper studying classified Landsat ETM + scene of 2001 to determine forest cover and 2000 UNEP data on human population, found ““highly significant” correlations between human population density on forest loss and degradation of natural eco systems”. This conclusion, instead of instilling vast confidence in major organisations, seems to highlight an insidious naive ineptitude in stepping up and acknowledging what we long knew.
There would appear to be a unanimous agreement that African forests seem imperilled both in extent and in quality. Harvested secondary forest quality may recover sufficiently to promote wildlife and Crowned Eagles, if left only a few decades. But this time period is seldom if ever able to pass without yet more human incursions by a burgeoning and land focussed population.

So much for Central Africa, what of East and Southern Africa?

The highlands of Ethiopia were previously cloaked in juniper forest, and its moist south western lowlands supported rainforests. The highland forests possibly extended their range to their northern most distribution. It must have been a veritable heaven for Crowned Eagles. In 3 years of field work in Ethiopia I knew of one pair near Addis Ababa at Menegishu Forest and another in a deep and rapidly deforested valley near Menz. The forest cover in Ethiopia today is mostly exotic, even within protected areas, staggeringly devoid of wildlife and very much disturbed by a vast rural population. Ethiopia is known for its eucalyptus forests that fuels the nation, tenuously holds top soil and stops the nitrogen cycle in its tracks. The prevalence of Cultural reverence to wildlife and especially birds is often quoted as a reason for high bird density. But I saw no such harmony and instead observed one of the highest levels of persecution. The road side sale of wild birds including ducks, owls and raptors was the highest I have ever seen in any country. Population growth in Ethiopia is bringing that nation to frightening levels akin to the highest densities of rural humanity found anywhere on earth. It is only the unreachable vertical walls of its myriad canyons and mountains that support its incredible raptor density. My colleague Lakew Berhanu is currently deeply concerned about the indiscriminate poisoning of raptors which we both witnessed as a routine part of a farmers life. Sadly the outlook for Ethiopian wildlife conservation is grim, with no evident government commitment. National Parks and reserves bear little resemblance to a protected area, and are all intensely utilised by a mushrooming human population. There are no private or community run conservancies. Of interest are the efforts of indigenous churches to protect the ancient forest groves around them. Foreign missionaries have been notable in instilling their brand of faith by obliterating many of these forests demonstrating their dominion orientated faith. The Crowned Eagle in Ethiopia is certainly at very low density and restricted to protected areas. It may be obliged to utilise exotics stands, but it is unlikely to ever be capable of surviving in the complete absence of indigenous (and thus prey productive) forests.
The status of Crowned Eagles in Uganda is probably as directly related to its human population density and associated forest loss. Protected South Western Ugandan forests with their central African affinities certainly have comparable densities. The work by Skorupa and Struhsaker show similar densities to West Africa, due to similar densities in monkeys. Uganda is interesting for it spans typical central and west Africa forests with the East African dry savannah forest. The biology to the species may be best known in studying both groups in this single country. Forests today are often isolated patches surrounded by Sugar Cane or Oil Palm plantations. Some of the densest rural human populations live adjacent to these forests. Edge-effect on the last stands is taking its gradual and certain toll on forest quality and plant diversity. In a recent trip to Uganda (Feb 2011) I noted forests burning for 128km, from Queen Elizebeth N.P. to Kibale, to Fort Portal to Mubende it was solid smoke and fire. There was little to note other than the absolute confinement of forest endemics to fully protected forest blocks. Anything outside is destined for use, agricultural development or removal and cannot support Crowned Eagles. It is debateable if the “half” protection offered by new “biosphere protection” concepts, will in the end work.
From within East Africa the 99.4% loss of Gishwati Forest (100,000 hectre) between 1986-2001 in Rwanda shows the human potential in the sub-region for removing protected forests with the simplest of tools for agriculture, not commercial mechanised forestry. While the 1994 genocide accelerated the destruction process due to an influx of refugees it was the familiar unsustainable practises of subsistence farming and cultivation that denuded the forests. The same inflexible processes is copied throughout sub sahal Africa with no foreseeable turnabout prior to complete habitat loss.
Although my very short experience in Ivory Coast was limited to Tai Forest (the largest remaining and best quality West African forest) and a breezy flight over the tiny Mt Peko National Park with Guy Rondeau and his wonderful ultralight, both he and Susanne Shultz acknowledged that Crowned Eagles were dependent on protected forests in that, one of western Africa’s most stable countries. It certainly looks doubtful that they could survive outside because what hasn’t been clear-felled, is trashy secondary scrub with palms and a scattering of a few majestic remnants. Road sides are interrupted with men holding struggling live wild animals for sale, and villages openly display smoked monkeys, duikers, golden cats and birds for sale. Gin traps, snares and weapons are sold overtly and the culture of wild animal hunting for food is pervasive. How can wildlife exist outside of protected areas as this demand is already far beyond the sustainable level? Nearby Liberia would seem to hold great promise in that it has vast primary forests due almost solely to past civil instability. With stability will come mechanised forest removal of an unprecedented kind for each timber block is already purchased.
While Tanzania has the largest extent of intact natural environment in East Africa, similar patterns of degradation are in process. Forest conservation in Tanzania faces great challenges, not the least of which is fragmentation. Forest patches scatter main forest blocks and are interspaced with rural farmlands. Eagles may hop from patch to patch picking a living off whatever medium sized wild mammal can cope with the restraints of isolation.
Resources to effectively protect forests are insufficient. The smuggling of some hardwoods and Scandal wood by Tanzanians operating in Kenya might indicate an overharvest of these trees within country. In recognition of the fate facing forests the government has recently established reserves and national parks in some unique forests with high endemism.
Visiting forests is not a casual business in Tanzania as it is elsewhere (unless war torn) for it requires extensive paper work, permits, hiring of officials and unaffordable entry and research fees. The combined effect surely restricts those that have made the major contribution to African ornithology, the non-professional naturalist. It certainly means that little is known about Crowned Eagle numbers.
In comparison with Kenya the numbers of raptors in Tanzania seem poor (from recent unpublished data from J.M. Thiollay and myself) and unlike Kenya the prevalence of large wildlife species outside of protected areas appears much less. Private and community conservancies, the saving grace of Kenyan wildlife is largely inapplicable and of course one must question the ecological impact of legalised hunting and live bird export trade. Outside of national parks, Tanzania has a far smaller percentage of wildlife than Kenya, so despite its potential it falls short of expectation.
Human population growth remains one of the highest and proportional natural resource depletion is a certainty. The general population depend upon indigenous tree charcoal/firewood for cooking and are a land based culture taking what they need directly from that around them. Given its overall higher human holding capacity, intensive land use is possible over a much greater part of the nation than within the arid desert lands of Kenya or Ethiopia. Tanzania has long had a propensity for massive agricultural schemes and projects which may have far reaching effects. The Bio-fuel plantations planned will certainly divide some forests if not consume them and Carbon credit payments have been incongruously made for planting exotics in indigenous landscapes! With regard to its natural environment Tanzania has a considerably better head start and will enjoy a longer life span but ultimately I believe it faces an identical outcome. As Leslie Brown once noted, Africa has repeatedly demonstrated its capability to outgrow the ability of the land to sustain its human population. And Tanzania is growing at a tremendous rate and cannot justify the export of Crowned Eagles. (see Bird Trade and export below).
Entering the miombo woodland of southern Tanzania and Zambia the wildlife holding capacity plummets, spreading browsers and grazers out over larger foraging areas. I had heard of the cheering sight of enormous swathes of low canopy forests and the relative low density of human habitation…a seeming contradiction in our part of the world. But when one stops to look and listen the forests are subdued and it is apparently not entirely the result of the hand of man. Crowned Eagles do live here, in the drainage lines where trees are taller, but they must do so at lower density. But these woodlands are today the target of professional woodcutters and charcoal burners, transporting fuel across borders. The international trade of fuel wood is now extremely serious and will certainly grow as fast as the human population. The drainage lines in miombo woodlands offer scant water resources and are prime areas for human passage and settlement. It is doubtful if Crowned Eagles prosper outside of national parks in this environment where the bush meat trade greatly suppresses the wildlife holding capacity.

Prey delivery, © Simon Thomsett

Malawi was one country I hastened through I fast as I could as we saw just one Fish Eagle and a few Eurasian Hobbies. The informal development of the country, the obviously burgeoning human population, the denuded forest ridges and scant opportunity for wildlife, let alone a major avian carnivore is all too obvious. I was reminded that a drive by summary was a harsh and inaccurate way to assess a country. I remained persuaded, by what I saw from afar and an eye witness account by a Malawian that Crowned Eagles still do occur in the lush and beautiful steep wooded hills. But today they must be at low density, and one guaranteed to get much less very soon.
South of Lusaka in Zambia the infrastructural nature of Africa takes a distinct twist, felt by every overlander and not difficult to articulate. There is an order, cleanliness, and neat organisation manifested by comparatively immaculate roads, neat roadside picnic tables and the monotonous wire fence-lines that follow you relentlessly to the Cape. Human populations are more centralised to villages and not so spread out across vast rural areas. Driving is not a hectic obstacle course of myriads of vehicles, bicycles, pedestrians and livestock. Harsh subsistence farming, obvious natural resource dependency, vast impoverished landscapes and abject poverty lifts like a foreboding cloud. That is not to say that there are not similar problems, but it does warn one equating east and southern Africa from an economic and environmental point of view. Here the rules change, and from the Zambezi south it is not hard to imagine an order and preciseness to natural resource and wildlife management with regard to where it is allowed to live and where it is not.
Zimbabwe has of course seen a dismal decade of land changes for the worse, but that staunch Zimbabwean Ron Hartley did sagaciously note that from a raptorial point of view the disruption of mechanised farming and collapse of order may have inadvertently promoted the conservation of some species of raptors. But Crowned Eagles probably did not fare so well under these land change circumstances. Ron showed me some photographs of nesting sites of Crowned Eagles in Zimbabwe that surprised me. These birds nested in baobabs on the side of hills in dry almost nyika terrain. Other pairs in the Matopo Hills also nest in drier and denuded terrain than expected. But these sites do have a varied and convoluted terrain, with nooks and crannies, valleys, overhangs and hideaways that allow a Crowned Eagle to exercise some of its particular skills. In Kenya, similar fractured landscapes can also be utilised by Crowned Eagles, such as the black gigantic volcanic rubble fields of Tsavo West, lower Chulu Hills, Kibwezi and Soy Sambu. These are jungles of boulders covered with low growth interspersed (in the past) with high trees. Just what is the density of these eagles is open to question. Given the dry baobab nesting Crowned Eagles it begs that we not overlook similar habitats in the rest of Africa for these eagles.
In general of course, the Crowned Eagle remains a forest species, and Zimbabwe is not a forested nation and looks to seeing less of it in the future. Nevertheless Zimbabwe, despite its recent history is now widely seen as a place for investment and recovery, as it still has an infrastructure envied by most of Africa, and less than half the amount of people per unit of land than Kenya and without its reckless population growth. Their parks, ravaged as they have been remain surprisingly intact with undoubtedly better management and less livestock density than much of stable East African parks. It is not surprising therefore to hear that Crowned Eagles within parks appear to have remained stable, but those outside them have declined.
Unfortunately Botswana and Namibia as promising as they are from a wildlife conservation aspect are by nature poorly endowed with forests. One wonders what the heart of Angola and Mozambique hold, for vast areas look to be having near sustainable numbers of people and to be much forested. South Africa is much drier than I ever suspected with only the low moist east holding much promise.
In South Africa the species is known to live in very close proximity to humans (famously in Durban), to utilise forests planted with exotics and to nest in Eucalyptus. I would not have thought it possible had I not visited South Africa in 2009, and despite not having seen a single bird, am prepared to believe it. South Africa is at such variance with the rest of Africa that it stands alone. Allowing land owners rights over wildlife would seem, (not without some justification in our country) tantamount to endorsing their immediate eradication, and yet here wildlife prospers. Charcoal is a thing bought in supermarket bags made of exotic brush and used to prepare their delicious outdoor meat feasts. I believe much of the security of their Crowned Eagles is because of the sanctity of their forests, lack of fuel wood and charcoal dependence for everyday cooking and the absence of the bush meat industry. The existence of glossy bird magazines, a massive domestic tourism market and the successes of conservation programmes aimed at raptors are all responsible for the occurrence and continuance of these eagles in human environments. I understand that this affable relationship with raptors was not always the case and that improved education has seen a recovery of many species of previously persecuted raptors. While they can say the Crowned Eagle is stable I wonder how much more there were previously. How much of South Africa was historically indigenous forest and how much has it lost? The question might be overlooked in accepting that South Africa changed so long ago from its ‘pristine’ post western influenced state. Yet it is of interest for if one can argue a decline of 25% to 50% from some historical record in the 1800s then one has a debatable view if one says the species is doing well today. In Eastern Africa, South African wildlife conservation methods is seen as either an example of excellence to be promoted or a dismal failure to be avoided. So little of its land is under national parks (almost half that of most east and southern African Counties) and game farming and private hunting reserves may arguably not compare in their ecological integrity to much of what we accept as even impoverished landscapes in Eastern Africa. True, Eastern Africa must learn an enormous amount when it comes to having to fence and manage areas for wildlife, as it will have to. But for now most nations opt not to follow their example and aim to maintain intact unfenced eco-systems (despite there being a long overdue and obvious need to fence for many areas). Confusion exists therefore in comparing South African conservation with other nations. While it may have succeeded in maintaining a stable and well tolerated population of Crowned Eagles, it does not mean that this situation applies across the continent.
The core of the species must be deep within the West and Central tropical and rain forests. The forest of Liberia, Ivory Coast, Ghana, Nigeria, Cameroon, Gabon and the Congos are complex entities to understand given their vastness, overall destruction and their incredible ability to regenerate and recover.

Part 2 of Simon’s writing about the Crowned Eagle can be found here:
http://www.africanraptors.org/simon-thomsett-on-the-african-crowned-eagle-part-2/

André Botha

It is a pleasure to write an introduction for an interview with André Botha.

André is a life-long birder with a special passion for raptors who loves the bush. He has travelled widely in southern Africa (and other parts of the world) and is at home in the lowveld, Kalahari, Zambezi delta, watching the Black Eagles of Johannesburg and many other places. I have travelled in the bush with him on numerous occasions and I have always enjoyed his calm, measured approach – except for odd occasions with tuskless cow elephants!

As a partial Luddite, my affection for modern technology is strained at best, but André utilises it at every opportunity to achieve his goals – particularly with photographing and recording birds. I enjoy watching how André logs the location of virtually every bird he sees whilst travelling and never ceases to share these data with the rest of the birding community in southern Africa.

Apart from his personal aims and activities, probably the thing that is most obvious to me about André is his ready willingness to work and collaborate with anyone whose aims are similar – that is, the conservation of raptors. It is this inclusiveness that has been a major part of the successful transition from the previously separate Raptor Conservation and Vulture Study Groups into the Birds of Prey Programme of South Africa’s Endangered Wildlife Trust.

Throughout his travels and experiences before joining the Endangered Wildlife Trust, André established an effective network of contacts with people who have a like-minded goals – the conservation of nature, landscapes and, of course, raptors. This network is now a large part of his work with the Birds of Prey Programme and it is growing all the time.

I look forward to working with André well into the future and in the meantime enjoying his easy going company. No doubt his thoughts on raptor conservation in South Africa will be of interest to many readers.

Campbell Murn – The Hawk Conservancy Trust

African White-backed Vulture 1st Year Juvenile Phabeni Rhino Carcass KNP, © André Botha

1)How many diurnal raptor species do currently breed in South Africa?
Due to the fact that we prefer to focus on the entire southern African region, I will answer this question in this context. There are 54 species of diurnal raptors known to breed in southern Africa.

2) Are there species of which all or large parts of the world population breed in South Africa?
Five raptor species are considered endemic or near-endemic to the region, namely the Cape Griffon Gyps coprotheres, Forest Buzzard Buteo trizonatus, Jackal Buzzard Buteo rufofuscus, Black Harrier Circus maurus and Southern Pale Chanting Goshawk Melierax canorus.

3) What is the conservation status of those species?
Two of these are listed in the Red Data Book of Birds of South Africa, Lesotho and Swaziland (Barnes, 2000), namely the Cape Griffon and Black Harrier.

Amur Falcon Adult Male Devon district Gauteng © André Botha

4) How is the overall situation for raptors in South Africa? How many species are endangered?
23 Species of raptors and owls are currently listed in the above publication, approximately 25% of the country’s raptor diversity.

5) In many parts of the world electrocution is a serious problem to large raptors. How is the situation in South Africa and what is done to reduce the number of victims?
Sadly, the situation is not much different in South Africa and we have been working with Eskom, our major supplier of electricity in the country for many years to attempt to address the impact of electrocutions and collisions with lines by birds. We are in a fortunate position as Eskom acknowledges the fact that their infrastructure impacts on raptor and other bird populations and attempts to reduce this where possible. South Africa’s electricity infrastructure is expected to double over the next 20 years due to the increasing demand for this resource. It is vital that we work with the engineers who will be responsible for this to ensure that raptors and their habitats are affected as little as possible. Alternative methods of electricity generation are also finding their way here and we are aware of many applications for the establishment of wind-farms, especially in the arid western parts of the country. We have the opportunity to comment on and influence the siting of these to hopefully minimize the impact thereof and Jon Smallie and his team from the EWT’s Wildlife Energy Programme is to ensure that this is done.

6) How important are large predators like Lions, Leopards or Cheetahs for raptors, for example as a provider of carrion or other ecological effects they have on the habitat where those large carnivores live?
With the exception of large conservation areas such, as the Kruger National Park and adjacent reserves, large mammalian predators do not play a significant role as providers of food for avian scavengers. In fact, the presence of such animals on land outside of conservation areas could indirectly have a negative impact on raptors as they often become the victims of secondary poisoning due to baits placed out by livestock owners to try and control predators.

Bateleur Malilangwe Zimbabwe © André Botha

7) What is the current status of the African Crowned Eagle in South Africa? What threats does the species face, how has the population developed during the last decades and are there any conservation projects for the species?
It is currently listed as Near-Threatened (Barnes (2000) and has a limited and fragmented distribution due the degradation of its indigenous forest habitat in the country. The Crowned Eagle Action Group currently monitors about 28 known and historical nesting sites of the species in the forestry areas of the Mpumalanga province and is actively working with foresters to ensure that active nest sites are not affected by their activities. A few pairs of Crowned Eagles have actually adapted to the introduction of alien species and now nest in exotic plantations rather than indigenous forest.

8 ) How is the situation for Martial Eagles?
The species is listed as Vulnerable in South Africa (Barnes, 2000) and the distribution of this species was severely reduced due to factors such as habitat loss, persecution and poisoning. As with several other large raptors, the bulk of the South African population now occur in large conservation areas.

9) How do you see the future of Martial Eagles and African Crowned Eagles in South Africa?
With growing human populations and the accompanying demand for resources, the habitats that these species depend on faces continued pressure. It is imperative that we encourage land-owners and communities to strive to manage such habitats in such a way that these birds are able to exist without the threats that historically and currently affects them. This can and has been done to good effect, e.g. in the southern Kalahari, and examples such as these should be used to encourage us to continue and expand on the successes achieved in the past.

10) Do vultures suffer from illegal poisoning in South Africa?
Yes, poisoning continues to be a major threat to vulture populations in the country. A major current concern is the fact that birds are harvested for the muthi-trade in certain areas and poisoning is one of the easiest methods that poachers use to acquire birds.

Immature Bearded Vulture Giants Castle © André Botha

11) Is overhunting of ungulates and other mammals a problem for vultures and other carrion eating birds like the Bateleur or Tawny Eagles?
Over-hunting per se is not really a problem at present, although this has certainly had an effect historically when most of the large herds of game on the plains of southern Africa were extirpated by settlers resulting in the reduction of available food for raptors and vultures. Popular opinion is that the establishment of the game farming industry in South Africa since the 1970’s has benefitted raptors and vultures. This is a statement that is not necessarily based on fact and is something that needs to be investigated.

12) Is there a difference in the population development of raptors inside and outside of protected areas?
Yes, there certainly is a significant difference and certain small protected areas are simply not large enough to sustain viable populations of raptors in their current state. Unless we address this as a matter of urgency, raptors may in due course only occur in protected areas.

13) How is the attitude towards raptors among the people living in South Africa?
Attitudes towards raptors vary, often from individual to individual and land-owner to land-owner. We have found that most land-owners are generally pleased to have raptors on their property, but that this attitude may change in times of drought or other difficulty when conflict may arise and some land-owners may have the same approach to raptors than they do to predators such as jackal and caracal.

14) Are raptors still illegally persecuted?
Sadly, yes. All raptors are protected by legislation, but this does not seem to deter individuals intent on the persecution of raptors or any other wildlife.

15) Some raptors may adopt well to urban areas, even large eagles like the Verreaux’s Eagle. The EWT has an Urban Raptor Conservation Project. What is it all about?
The Project aims to create greater awareness of large raptors and the issues that affect them with the general public that often feel themselves removed from the natural environment. Bo van der Lecq and his team of volunteers monitor a range of nests in the Gauteng-region and work with local authorities and other interest groups to safeguard remaining sites and foraging areas for these birds. He was also instrumental in the erection of a free-standing artificial nesting platform for a pair of Verraux’s Eagles Aquila verrauxii in southern Johannesburg after their nest on an electricity pylon was destroyed in 2008. The pair successfully raised a chick during the last breeding season.

16) What other conservation projects does the EWT currently have for raptors?
Due to the range of species, scope of threats and substantial geographic scope, the challenge in this regard is vast. The Birds of Prey Programme currently manages a range of projects focused on a variety of habitats and species. We work with a range of other organizations, partners, associates and individuals to achieve our objectives as this challenge is certainly too great for a single NGO to address. The well-known Vulture Study Group lives on in our work focused on vultures through the Cape Vulture-, Bearded Vulture- and Traditional Medicine Task Forces as well as the Sasol Vulture Monitoring Project that focuses on a range of sites throughout South Africa and beyond. A number of fieldworkers are currently active in areas such as the Kalahari, Karoo, Maloti-Drakensberg and the Lowveld/Kruger National Park working on the full spectrum of species and issues relevant to these sites. Our African Grass Owl Task Force looks at this species in particular and we assist in the work of the Taita Falcon Survey and Crowned Eagle Action group on a continuous basis. As is often the case, limited resources are often a significant factor in restricting our ability to address the many issues out there.

17) How can people help the EWT to protect raptors in South Africa?
We actually have a pamphlet as part of our range of awareness materials in this regard and people are encouraged to keep an eye out and report any nesting or roosting activity, threats, impacts, deaths or injuries to raptors that they are aware of in their area. Our rather large base of volunteers consists of individuals who often started out by doing this and developed their interest into a range of activities to benefit raptors in their vicinity.

18) What do you think are the most important steps that have to be taken in the future to secure ecologically significant and stable or rising raptor populations in South Africa?
The biggest challenge we face in conservation in general is to make humanity realize that our natural resources are finite and that just about everything we do affects the environment and the species that we share the planet with. We currently seem to carry on as if there is no tomorrow and short-term gains are often our only motivation. Unless we arrest the continued destruction, fragmentation and degradation of the habitats that raptors and their prey need to exist, we will not be able to achieve conditions suitable for the stabilization and even increase of raptor populations anywhere. Although it is important to be focused in the area or range of species that we focus on, we must also strive to see the bigger picture and work together to the benefit of raptors from a continental and global perspective to achieve significant change. As always, appropriate research and long-term monitoring, supported by effective and focused conservation action will make a significant towards achieving this.

19) What was your most amazing experience with raptors?
After more than 20 years in Africa, there are far too many to mention! Examples that come to mind include an immature Bearded Vulture “learning the ropes” of using an ossuary in the northern Drakensberg, a wild Lanner swooping low over my head to snatch a Longclaw that I flushed from the grass in the same area, watching a Martial Eagle tussle with a large Water Monitor for more than an hour in Kruger and spending a morning at Lake Naivasha, Kenya with its many African Fish Eagles with Munir Virani. A visit to any of the large roosts of migratory falcons in the late summer in South Africa is a spectacle in itself! I would still like to witness the masses of raptors on migration in the Mediterranean or Panama one day…

20) André, many thanks for answering our questions

Further information about the EWT’s Birds of Prey Program can be found here:

BIRDS OF PREY PROGRAMME

A Seychelles Kestrel on a nest. Photo by Jeff Watson

Katiti in Creole, crashed to approximately eight individuals since the 1940s before the population recovered, apparently unassisted, a genetics study published in the October 2009 Biological Conservation Journal has revealed. This crash, it is thought, approached the severity of the genetic bottleneck of the Mauritius Kestrel whose numbers reduced to only four known individuals in the wild in the early 1970s. Intriguing however, is that the Seychelles Kestrel seems to have recovered undetected and without intensive intervention. Methods to measure levels of genetic diversity in ancestors have improved to allow pinpointing of major changes in a population’s history. Using genetic data from 100-150 year-old museum specimen, and comparing this with data from current populations, the study established that at one point the population crashed. And then with very little conservation effort it recovered. Nirmal Shah, Chief Executive of Nature Seychelles, was part of the study led by Kent and Sheffield Universities in the UK. A clear understanding of the recent population history of a species is important because it helps managers to anticipate problems associated with a dip in population. Island endemic bird populations generally have lower levels of genetic diversity than species with a continental distribution. This increases inbreeding and its associated risks of extinction. Inbreeding causes problems such as lowered reproductive fitness and vulnerability to disease. Preservation of genetic diversity is thus the basis of many conservation efforts because diversity is vital for evolutionary adaptation, and adaptation is key to the long-term survival of any species. Therefore, interventions on behalf of endangered birds on islands usually involve boosting population sizes in order to vary the genetic material. This has been true for species action for most of Seychelles endemics including the Seychelles Magpie robin Copsychus sechellarum (Pi Santez in Kreol) and Seychelles warbler Acrocephalus sechellensis (Timerl Dezil). In the past, conservation efforts relied on historical accounts and some anecdotal data. Historical records have variously described the Seychelles Kestrel as “tolerably common” in the 1860s, “frequently seen in all islands” in the 1930s, both “well distributed” and “rare” in the 1950s, “Critically Endangered and close to extinction” by 1966, with “probably less than 30 birds” confined to Mahe in 1969.

Seychelles Kestrel Chick. Photo by Jeff Watson

Surveys in 1973 located 49 pairs and estimated a population of 150-300 birds and by 1981, there was an estimated carrying capacity of 370 pairs. In 1985, the Katiti was described as being “far more numerous than previously thought”. Surveys in 2000-2001 suggest that the population remained stable in the previous 25 years. Although genetic data can help show changes, it does not explain why the changes occurred. Habitat loss, development and fires as well as predation and competition by introduced species is thought to have caused the decline of the Katiti. Kestrels were also killed because they stole chickens and were thought to be a bad omen. The Seychelles Kestrel recovery from a severe population bottleneck relatively unaided by intensive conservation efforts is extremely rare. Many seemingly comparable ‘unmanaged’ species recoveries can often be explained by indirect intervention, such as broad-scale ecosystem management. But the study bears a note of caution. “Given the current pressure on global conservation resources, this recovery may appear encouraging. However, outcomes such as this are likely to be the exception rather than the rule for other endangered island endemics.” Source: Natureseychelles/Zwazo – Seychelles Conservation Magazine Number 21 2. Katiti: Myths unfurl Professor Massimo Pandolfi and Dr. Michele Barilari from Urbino University –Italy which has an MOU with Nature Seychelles have for the last couple of years been conducting research on Seychelles Kestrel (Katiti). Here they give a sneak preview of their stirring findings exploring the diverse myths on this inimitable bird of prey. The Seychelles Kestrel (Katiti in Creole) is endemic to the granitic Seychelles and little is known about its ecology and behaviour. Its ancestors came from Africa and Madagascar and the life in small and isolated islands, principally covered by a wide and deep tropical forest, made it a tiny raptor (no more than 90 g, the smallest kestrel in the world) with wide wings and long tail like Sparrow hawks. The life on the Seychelles forest changed not only its aspect, but transformed deeply its behaviour from a grassland hunter into a small raptor able to move and hunt inside dense forests. The low detectability of the Katiti, due to the nature of its habitat and behaviour, makes difficult the observation and the study of this bird, but the high conservation value of the species (classified as Threatened by IUCN) and its importance in the Seychelles ecology motivated us to spend long hours searching for this enigmatic bird in the forests of Seychelles. The Katiti today has a world population of only 350 pairs and the distribution of the species is not uniform in the archipelago: the largest part of the population (near 300 pairs) is confined to Mahè and Satellite islands, 40-50 pairs on Silhouette, only a few pairs in North and Praslin. At the beginning of the century the Seychelles Kestrel was extinct on Praslin till the reintroduction of 13 birds in 1977. During the following years the population reached 10 pairs (Watson, 1989), but recent studies (2003), carried out by Nature Seychelles, demonstrate that the reintroduction was not a complete success because on the island were present only 6 pairs and most of them were not attempting to nest or failed in the first phase of the breeding season. An island of the size of Praslin could be expected to hold more than 90 pairs, based on observation of the Mahè population done by Dr. J. Watson in 1980. We can wonder now if some ecological aspects of Praslin could be a limiting factor for the local population or if the reduction of the population is the result of a normal dynamic (statistical fluctuations) of a small and (almost) isolated population. A study group of the Urbino University directed by the ornithologist M. Pandolfi began to follow the Katiti with a first survey on Silhouette in 2004 where, with the help of Justin Gerlach, some observations on the species were done and blood samples for the genetic evaluation collected. Later, in 2006-2007, another survey was done in Mahè analyzing the distribution and the ecological preferences of the Katiti population in two different, forest and urban, areas.

Seychelles Kestrel with prey. Photo by Johan van der Watt

In 2008, with the collaboration of Dr. Nirmal Shah and Nature Seychelles, a group of us, Massimo Pandolfi and Michele Barilari, with three Master thesis students of the Urbino University, Diego Tarini, Carlotta Di Biase and Emily Pasquini, began a study on the critical Katiti population of Praslin with the aim to characterize which causes determine the different dynamics of the population between Mahè and Praslin. In the study we are trying to evaluate which ecological parameters might be limiting factors in the Praslin population. The distribution and breeding success of the pairs and some ecological parameters (and potential limiting) factor as predation, inter-specific competition, prey and nest site availability are being analyzed. In order to evaluate the predation pressure on the island, we placed “eggs models” in artificial cavities. Eggs models were made by moulding plasticine that retains impression of the bill or teeth of the predator aiding the identification. Plasticine eggs have been located in different habitat: forest, urban and sub-urban. Predation index was calculated as number of artificial cavities predated/days of exposure. Relative abundance of the main katiti preys, Green Day Gecko (Phelsuma sppl.) and Skinks (Mabuya secellensis), was evaluated with a Phelsuma index (scanning with binoculars 100 trees in each territory at a distance of 30m). The height from the ground of the single geckoes on the trees had been evaluated too. Skinks abundance was evaluated with transects of 500m x 3m in different habitat. We evaluated the local density of a nest site competitor and potential nest predator too, the Indian Mynah (Acridotheres tristis). Plots (300m radius) with a 10 minutes of observation had been realized. Once we characterize the distribution of the population and the limiting factor/s on Praslin we will underline a conservation program to increase the critically endangered population of Praslin.

This article has been reproduced by kind permission of Liz Wambui and Nature Seychelles.

Source: Nature Seychelles/Zwazo – Seychelles Conservation Magazine Number 19