African Raptors

The online home of African Raptor interests

African Raptors header image 1

Interview with Robbie Whytock about African Crowned Eagles and other raptors in the Ebo Forest

September 12th, 2015 · Interviews

I met Robbie by chance in 2005 during his first visit to Cameroon. At the time I was based in Limbe, where the Ebo Forest Research Project offices are based, and Robbie was introduced to me by a mutual friend who shared his interest in birds. Robbie had arrived in Cameroon to work with another local conservation NGO with an interest in raptor conservation, but things seemed to be at a standstill. Robbie persisted, and during his time in Limbe he soon became known for his avian expertise. robbie_small

Most conservationists in Cameroon are focused on mammal conservation, and it was a breath of fresh air to meet someone with wider interests.

In 2008, we invited Robbie to work with us in the Ebo forest, initially as a volunteer and later as a research associate with the EFRP. Robbie had no formal scientific training at the time, but his knowledge of Cameroon’s forest birds and drive to master ecological research methods have resulted in three peer-reviewed publications in recent years. After two years of working with us, Robbie returned to the UK where he began an undergraduate degree in Ecology at Stirling University, graduating with first class honours in 2014. During that time he continued to return to Cameroon on a regular basis, and successfully secured funding to research the impact of bushmeat hunting on birds in the Ebo forest. These achievements led to him securing a funded PhD position at Stirling University in 2014.

Robbie’s enthusiasm for tropical forest biology, and ability to work effectively with local people, has made him a pleasure to work with. I expect he will make many more worthy contributions to bird conservation research in future, and I am delighted to be able to introduce him.

Bethan Morgan

 

 

Can you give us a quick overview about the ecology of the Ebo Forest (landscape, habitat, etc)?

The proposed Ebo National Park covers 1,100 km2 and is dominated by secondary lowland and sub-montane rainforest. There are also large areas of raphia swamp and marantacea forest and, where soil is thin on hill tops, small areas of savannah-like habitat. Much of the forest was inhabited until Cameroon’s independence in the 1950s and 60s, when civil war forced the population to abandon remote villages and move to the forest edge. The remains of abandoned villages can still be seen throughout the forest, with their locations marked by upturned iron pots and ageing stands of oil-palms. The terrain is challenging, with seemingly endless river valleys that undulate steeply between 250 m and 1100 m above sea level. The forest is particularly important for its primate community, with one of the largest known populations of drills, an endangered cousin of the better-known mandrill, as well as high densities of the endangered Nigeria-Cameroon Chimpanzee and a small population of Lowland Gorillas. There are two main seasons, distinguished by rainfall, with the wet season beginning in April, peaking in August and ending in October. Temperatures in the dry season peak at around 33oC, with lows of around 24 oC. Even in the dry season it is extremely humid, rarely dropping below 80%. The Ebo Forest Research Project operates a permanent conservation-research program in the forest, with two permanent research camps, one of which has been manned permanently since 2005.

 

 Tail feathers from a white-thighed hornbill (Bycanistes albotibialis) discarded in a hunting camp

Tail feathers from a white-thighed hornbill (Bycanistes albotibialis) discarded in a hunting camp

 

What raptor species are present?

We’ve so far recorded sixteen diurnal raptors inside the forest and at the forest edge. Yellow-billed Kite, Palmnut Vulture and African Harrier-hawk are the most abundant. Yellow-billed Kites scavenge for discarded food in villages, breeding in isolated trees above agricultural plantations. Palmnut Vultures and African Harrier-hawks are widespread throughout the forest edge and interior. Both species are generalists, and Palmnut Vultures in particular feed on a wide range of prey, ranging from palmnuts, giant African land snails, freshwater crabs and carrion discarded by hunters.

Other common species found at the forest edge include Black Sparrowhawks, which regularly take chickens in villages, as well as African Goshawks and Lizard Buzzards. Forest specialists, which are less well-known, include Crowned Eagle, Cassin’s Hawk-eagle and Congo Serpent-eagle, as well as Long-tailed Hawk, Red-thighed Sparrowhawk and Chestnut-flanked Sparrowhawk.

Red-necked Buzzards are occasionally seen at the forest edge, and I’ve once seen an African Fish-eagle. The most recent addition to the list was a European Honey-buzzard found with a broken wing near Bekob camp, a research station run by the Ebo Forest Research Project. I’ve also seen the occasional Common Kestrel, but these are normally quite far from the forest edge near larger villages and towns.

Owls are generally under-recorded in Ebo, but we’ve seen African Wood-owl, Barn Owl and Sandy Scops-owl. Others have also recorded Red-chested Owlet and Shelley’s Eagle-owl.

What are the challenges when studying raptors in the Ebo Forest?

There are two main challenges; the first is negotiating access to the forest with local people. It’s important that those who rely on the forest for economic and cultural reasons are involved in research and conservation activities, but sometimes they can feel that their livelihoods or cultural practices are under threat. It’s the responsibility of external researchers to work in co-operation with local people, and make the objectives of any research activities clear. This can be a long and slow process, involving lots of consultation with local chiefs and elders, often in several villages. Discussions can sometimes go on for several hours or even days.

The second problem is the forest itself, with endless mountains and dense vegetation it can be difficult just walking from a to b, never mind trying to actually see or hear a raptor!

 

Palm nut vulture (Gypohierax angolensis) feathers discarded in a hunting camp

Palm nut vulture (Gypohierax angolensis) feathers discarded in a hunting camp

What raptors are hunted for bushmeat or other purposes?

We’ve so far recorded Cassin’s Hawk-eagle, Crowned Eagle, African Harrier-hawk, African Goshawk, Palmnut Vulture and remains of other unidentified raptors as bushmeat. Owls, such as African Wood-owl, are also killed due to superstition.

How is the Palmut Vulture affected?

Our 2014 study (published in the journal Oryx) found that Palmnut Vultures were the most commonly hunted raptor in the Ebo forest. This could be because they are the most common raptor in general, and therefore readily available to hunters, or because hunters target them specifically. We are currently conducting a study (funded by a Rufford Small Grant) to try and establish why people hunt and eat raptors, and to assess the sustainability of hunting pressure. At present we don’t know the impact that hunting is having on palm nut vulture populations, but it’s likely to be negative given the species’ low reproductive rate.

What is the status of the African Crowned Eagle in the Ebo forest?

When I first travelled to Ebo I hoped to find crowned eagles at similar densities to the Tai National Park, Ivory Coast (~ one pair per 6.5 km2). Instead it took months for us to hear our first bird, and it was more than a year before I saw one. I haven’t yet had the chance to systematically assess the status of the Crowned Eagle population, but I expect densities to be much lower than those found in Tai National Park.

 

African wood owl (Strix woodfordii) killed in a village

African wood owl (Strix woodfordii) killed in a village

 

What is the main prey of the Crowned Eagle and how are the prey species affected by hunting?

In central African forests, Crowned Eagles will take a variety of prey ranging from duiker, colobus monkeys, guenons, other mammals and occasionally birds such as hornbills. All of these are heavily exploited for bushmeat throughout Central and West Africa, and many species are in decline as a result. Where hunting pressure is very high, colobus monkeys are among the most vulnerable species. These large monkeys feed on leaves, and once gorged with food they quickly lose their agility, have little stamina and are easy to hunt. In Ebo, Black and White Colobus have almost disappeared, and the endangered Preuss’ Red Colobus is hanging on in small numbers.

Although there is no firm evidence to suggest that bushmeat hunting has had either a direct or indirect impact on Crowned Eagles, it’s obvious that lower prey densities will at some point have an impact on predator populations. For example, research from Gabon suggests that Leopards are in direct competition with humans for prey (much like Crowned Eagles), and where hunting pressure is high, Leopard populations decline as an indirect consequence of hunting activity.

What is known about the ecology and status of the Cassin’s Hawk-Eagle in the Ebo Forest?

We know very little about Cassin’s Hawk-eagles. Like Crowned Eagles, we haven’t systematically estimated population densities in Ebo, but they are much more common than Crowned Eagles. I know of at least four territories in Ebo that occupy a total area of approximately 25 km2. This is four times higher than densities reported elsewhere (~ one pair / 100 km2). Pairs are often vocal, and display high above the forest canopy during midday. Territories always seem to be focused on steep-sided hills. On several occasions I’ve seen individuals soar high above a hilltop, then fly up to 1 km away from the hill before quickly descending into the canopy. The bird then disappears for some time, before reappearing out of the forest canopy at the same point on the original hill. This is repeated time after time. I expect this is a hunting strategy, with the birds flying away from the centre of the territory, high above the forest canopy to avoid being detected, and then hunting under the canopy as they return.

 

Cassin’s hawk eagle (Aquila africana) in the Ebo forest

Cassin’s hawk eagle (Aquila africana) in the Ebo forest

 

What needs to be done to reduce bushmeat hunting?

Despite some significant effort from international conservation NGOs and scientists over the past 25 years or so, there is no clear solution to the problem. People hunt and consume bushmeat for a variety of social and economic reasons, and these can differ greatly between communities. In Ebo, commercial hunters earn a living from hunting species that can be sold for cash in rural and urban markets, and this is the most damaging type of hunting. Subsistence hunters will shoot and trap close to farms and villages, and generally only target smaller species like squirrels or the occasional monkey. These are usually consumed by the hunter’s family or sold opportunistically.

Commercial hunting operates on a supply and demand basis, and unless we can cut the demand for bushmeat then it’s always going to be difficult to stop hunting. However, projects like the Ebo Forest Research Project can also have a positive impact, and hunting pressure in the vicinity of the project’s permanent research stations is greatly reduced, as hunters avoid the area fearing they could be caught.

There is a proposed National Park in the Ebo Forest. What is necessary so that the park can help raptor conservation?

It’s essential that the Ebo Forest is given full National Park status. Forests across Cameroon and Central Africa are being removed at an unsustainable rate to make space for agricultural industries and mining. Forest specialists, such as Cassin’s Hawk-eagle, cannot exist without intact forest, and the conservation outlook for these species is poor if we cannot preserve large, intact areas of lowland forest.

 

Bekob field station in the Ebo forest

Bekob field station in the Ebo forest

 

Is the area of the park large enough for a viable and long-term Crowned Eagle and Cassin’s Hawk-Eagle population?

The proposed park boundaries cover a large area (1,100 km2), and could certainly support a viable population of crowned eagles and Cassin’s hawk eagles. However, in the long term, populations are unlikely to persist in Ebo if the forest becomes isolated from other forest patches. Because of this we need to maintain a network of functional forest patches across the entire landscape.

How is the Crowned Eagle and other raptors affected by hunting in other parts of West Africa?

Very little is known about the status of forest raptors in West Africa. I spent two months in the Gola Rainforest National Park in Sierra Leone in 2013, and hunting pressure in general appears to be much lower there than in Ebo. Crowned Eagles were certainly far more common than in Ebo.

If tourists and bird watchers see illegally hunted raptors during their trips? What can they do?

Raptors are occasionally sold in markets or at roadsides in Cameroon, often alive. However, in these circumstances it’s important not to buy the bird, as this only encourages more hunting. There’s not an awful lot that can be done, but the Limbe Wildlife Centre in Southwest Cameroon has rehabilitated a number of raptors, including African Harrier-hawk, Palmnut Vulture, Black Kite and Fraser’s Eagle-owl, as well as thousands of parrots, so they would be worth contacting.

 

Typical hunting camp in the Ebo forest

Typical hunting camp in the Ebo forest

 

How do you see the future of the Crowned Eagle and the Cassin’s Hawk-Eagle  in West Africa?

Both species might eventually end up being confined to a small number of isolated forest parks in West Africa. The story in Central Africa is different though, where there are still very large areas of contiguous forest with relatively low human population densities. These areas will likely become the last strongholds for many of Central and West Africa’s forest dependent species.

What future research is necessary to learn more about the ecology and conservation of African Crowned Eagles, Cassin’s Hawk-Eagles and other raptors in West Africa?

We know that both forest and savannah raptors in West and Central Africa are becomingly increasingly threatened by habitat loss, hunting, poisoning and the trade in body parts for traditional medicine. However, the biggest problem is the lack of basic population and demographic data for most species. It’s impossible to determine how big an impact that potential threats might have on raptor populations without this baseline data. In many parts of West Africa raptors are legally protected from persecution, but there is little or no enforcement of the legislation. Therefore, we need to understand where to focus our efforts, should it be on the bushmeat trade, or the trade in body parts for traditional medicine, or elsewhere? If we have baseline population data we can identify the most pressing issues, and begin to target conservation efforts at specific threats. In the long term, this kind of data is best collected by local ecologists, and I think that supporting local researchers will be the key to future conservation success in the region.

What tips would you give young researchers who want to get started with raptor research (or other bird species) in West Africa?

In Cameroon, the Department of Animal Biology at the University of Dschang is fast becoming a centre for ornithological research. Projects like the Ebo Forest Research Project and others run by organisations like the Wildlife Conservation Society also support local and international students. BirdLife International partners can also be a good place to begin making contacts, and they have a presence in many West African countries. The A. P. Leventis Ornithological Research Institute in Jos, Nigeria, provides specialist ornithological training as part of the University of Jos.

 

View of the Ebo forest above the canopy

View of the Ebo forest above the canopy

 

What was your most amazing experience with raptors in the Ebo Forest?

From a hilltop vantage point, I once watched a female Cassin’s Hawk-eagle soar high above the forest canopy, almost out of sight, before disappearing into the trees behind me. Then, 10 minutes later, I was shocked as she appeared just meters above my head, landing silently in a dead tree stood next to where I was sitting. She spent five minutes or so preening before moving off silently. I then decided to call it a day, and as I was packing up, a male Crowned Eagle appeared out of nowhere above the canopy and began displaying across the valley, giving the best views I’ve ever had of Crowned Eagles in Ebo! I didn’t even bother trying to take a picture or raise my binoculars, just enjoyed the scene.

 

Robbie, many thanks for the interview!

→ No CommentsTags:

New interview with Shane McPherson about the urban ecology of the African Crowned Eagle

September 15th, 2014 · Interviews

I am very happy to be able to publish another interview about the African Crowned Eagle. In South Africa Shane McPherson is doing research on African Crowned Eagles that have adapted to an urban environment. This interview provides fascinating insights into the ecology of this  top predator in an urban habitat in South Africa.

Markus Jais

 

Introduction by Rowen van Eeden

Shane is a passionate biologist whose interests range a broad spectrum of our natural world, however he was perhaps always destined to undertake a study on African Crowned Eagles. His fascination began while assisting with rehabilitation and research of raptors mentored by Simon Thomsett in Kenya. With some mighty big boots to fill in the form of the legendary Leslie Brown, who has written numerous accounts of African Crowned Eagle biology, Shane was quick to identify gaps in our knowledge of Crowned Eagles especially regarding the urban eagle phenomenon. And it was from here that Shane set out to understand the habitat requirements, threats to, and the diet of these birds in the cities of KwaZulu-Natal, South Africa. Two years of research has been proudly submitted as an MSc for assessment in mid 2014. What makes Shane’s research so important is that with recent huge leaps and bounds in technology he has been able to collect data on; prey provisioning using cameras that can record data on a scale that would have been impossible in Leslie Browns era, and GPS tracking which has provided an intimate insight into the movements of urban Crowned Eagles. This data has raised awareness in the public and conservation circles with respect to the ecology and human interactions of Crowned Eagles, and distill some fears and misconceptions often associated with these immense predators.

Rowen van Eeden
Doctoral candidate
Percy FitzPatrick Institute of African Ornithology

 

Thank you for the opportunity to chat about my research. I am a Kiwi and have always been attracted to Africa, from my earliest days entranced by those BBC Attenborough documentaries. I feel so fortunate to have this incredible opportunity to live in South Africa and conduct this research. Simon Thomsett, who had a fantastic Crowned Eagle interview on ARN some years back, was to introduce me to this magnificent species in Kenya back in 2006, where I was flying and exercising a captive bred juvenile from his pair Rosey and Girl. This young eagle was subsequently released into the rift valley system later that year.

Currently, I have just endured months of thesis writing and submitted the Masters of Science manuscript for examination, so this is a timely opportunity to discuss the project. As long as I am working on the project regular updates can be found at facebook.com/CrownedEagleResearch

What is the scope and focus of your project?

This is currently an MSc project with the running title ‘Urban Ecology of the Crowned Eagle’. I am at the University of KwaZulu-Natal, Pietermaritzburg campus, with supervisor Professor Colleen Downs and co-supervisor Dr. Mark Brown. Broadly, I am surveying and researching around the southern KZN province of South Africa, including the Midlands, Pietermaritzburg, Durban, and the northern and southern coastal highways. The focus is on urban ecology of a population within the Durban Metropolitan Open Space System (D’MOSS). These urban eagles face particular challenges and interesting interactions with the urban wildlife and human population.

How many territories are you monitoring?

I have just prepared the spreadsheet for the upcoming field season and am shocked to see there are 119 ‘sites’ on this spreadsheet. While many of these are areas to concentrate more survey effort (‘nestless’ territories and distribution gaps), from this list there are 57 nests that I will monitor on a regular basis this year. Of particular interest are no less than 20 active pairs within a 500 km2 area of D’MOSS-urban mosaic. There are perhaps 2-7 undiscovered nests in this focal area which I hope to clear up this summer.

What is the main habitat for Crowned Eagles in your study area?

The Crowned Eagle is a forest species. Their paddle shaped wings and long tail are typical accpitirine adaptations for agility in tight spaces, while the dappled plumage allows them to melt into the moving shadows of the subcanopy, waiting in ambush above a game trail. Within the study area they are typically found in or on the edge of zonal forests; montane, scarp, and Indian Ocean coastal belt. Though, I would love to experience these eagles in the central African jungles – an environment which they are most perfectly suited, and also more threatened.

Locally the most extreme cases of occupancy are those pairs which can raise chicks within fairly small fragments of natural forest within the urban mosaic of Durban and Pietermaritzburg. Several nests are less than 50 meters from the door or veranda of a house! I am aware of other urban eagles further south in East London, Port Elizabeth and George, as well as a very well-known nest studied by Leslie Brown in the suburb of Karen, Nairobi.

 

 Crowned Eagle visits a gum tree nes

A Crowned Eagle visits a gum tree nest site adjacent to the industrial area of Pietermaritzburg. Photo by Shane McPherson, July 2012

 

Couple of African Crowned Eagles

A new-couple-of-the-year mating in a gum tree in Kloof. Photo by Mark Williams, July 2014

 

What is the preferred nesting tree?

Locally, the exotic Blue Gum Eucalyptus saligna is the most frequently used nesting tree. A greater variety of indigenous trees are used. I cannot say which species are selected as this requires quantifying the proportions of available suitable trees available – hindered by a swathe of analytical assumptions. The Blue Gum has traits which may be preferred; they grow rapidly to tall heights, the open radial branching pattern provides many good locations for a solid nest platform, and the powdery smooth bark is pretty difficult for monkeys to climb. Monkeys and baboons harassing eagles at the nest site is probably their most important natural threat. The use of Blue Gums by Crowned Eagles, Black Sparrowhawks, Harrier-hawks and Fish-eagles (all observed in my study area), complicates the issues regarding the management of exotic tress. The government organisation Working for Water and other local action groups clear a lot of invasive vegetation, and it irks me when a nest tree of a protected raptor is felled or ring-barked.

How big are the Crowned Eagle territories?

Five territorial adults have been fitted with backpack mounted GPS devices to specifically look at home range and preferred hunting habitats. The data collection is still ongoing for three of these birds so there is plenty of scope to extend the research. So far it appears that the home range primarily depends on the available area of indigenous forest. One of the female eagles used small fragmented forests across a range of 35 km2 of sugarcane land. Another female within the city has thus far used 5.8 km2 of mostly D’MOSS urban forest reserve. The home range of pairs in Tai National Park, Ivory Coast were 6.5 km2 (Shultz 2002) so it is surprising to suspect that similar small home range sizes can be maintained in this highly modified urban landscape. Perhaps contrary to common belief, the food resources in the urban environment are high and appear to suit the eagles quite well.

What is the preferred wild prey, and do the Crowned Eagles take pets like dogs or house cats??

The very essence of this research was to address this human-wildlife conflict. In recent years we have followed popular media and a general perception among the public of Durban that Crowned Eagles are targeting pets. Indeed there are almost annual cases of cats and small dog breeds being attacked, which often get sensationalized in the newspapers. So it was crucial to provide a balanced view on this topic. We have had a huge success in the use of nest cameras, possibly the first extensive study of this type for Crowned Eagles. In the last two years, cameras at 11 nests covering 1,600 days of monitoring provided a dataset of over 800 prey animals, 85% were identified to species.

What has been surprising is that the vast majority of prey (93%) is urban wildlife. Generally urban ecosystems provide abundant opportunities for a very small range of urban exploiting animals – think pigeons – but indigenous biodiversity is usually negatively affected. The D’MOSS system has protected a wide range of grasslands and forests and the diversity in Durban is possibly an exceptional global example for integrating wildlife into an urban ecosystem. Some of the favourite Crowned Eagle prey have adapted to urban resources; Rock Hyrax, Hadeda Ibis, Vervet Monkeys, Blue Duiker, and a variety of small carnivores (mongooses, genets).

Cats comprise 0.7% of the prey from these urban nests, they were not separated into domestic or feral individuals. No dogs at all were observed from camera studies. From this data it is clear that pets are not at great risk by adult eagles during the breeding season, however it is during the period where the juvenile eagle is preparing for independence that pet encounters become more frequent. This provides an avenue for effective education and management options.

African  Crowned Eagle male and chick at nest

The adult male T8 at Tanglewood Private Nature Reserve in Westmead, Durban. T8 has arrived at the nest with the back legs of a Blue Duiker, and is fitted with a GPS/VHF telemetry device from South African company Wireless Wildlife. Photo by Shane McPherson (nest camera).

How do Crowned Eagles hunt? Do males and females select different prey?

The Crowned Eagle has muscular legs, thick tarsi, short toes and huge talons. The pressure delivered to the talon tip is immense – and necessary when considering its prey options. The ability for Crowned Eagles to quickly incapacitate large prey is an adaptation shared by other ‘monkey-eating’ eagles. I have been told accounts by several people who have seen an amazing and probably widespread strategy for Crowned Eagles. This typically starts with the female soaring boldly over the canopy which incites the troop of monkeys to rush to the top of the trees, watch closely and bark at this threat… Suddenly the male eagle bursts upwards from below the troop, plucking a monkey on his way through. He, smaller and more agile, has taken a route below the canopy at high speed, arriving on the scene completely undetected. He needs to grip the monkey on the head to incapacitate it – a poorly aimed strike could result in a life-threatening tumble through the canopy, and the whole troop rushing to protect the struggling victim. I suppose you must be extremely lucky to see such a thing! Typically though the Crowned Eagle is an ambush predator and will sit in a hidden vantage point over some well used game trail or rockery, ready to swoop down onto a duiker or hyrax that moves into a vulnerable position. Typical prey are less than 5 kg in size, fitting neatly into a crowned eagles clutches; hyrax, young duiker, mongooses etc. Larger prey cannot be carried whole and the Crowned Eagle expertly guts then dismembers large prey – taking portions to the nest in successive trips.

It seems that the success rates between independent versus cooperative hunting strategies merits a lot more research, and I’d be very interested to know whether the adult pair goes out hunting together once the chick is getting older and ready to fledge. Trouble is – the thick forest is an extremely difficult place to observe the eagle and its prey, without being noticed.

How long to the young stay in the nest and after fledging, how long are they dependent on their parents?

The common held belief, which is confirmed from the tropical regions, is that the crowned eagle breeds biennially – one chick every two years. The juvenile eagle has a lot to learn about hunting large prey and intelligent species such as monkeys. Again a surprising difference with the urban eagles is numerous cases of annual breeding. We are finding that in a few cases the adults forcibly evict the juvenile from the nest area in order to breed every year. The breeding productivity and post-fledging dependency period are topics I hope to address while extending this research.

What is known about the dispersal of young Crowned Eagles?

This is an excellent question and as far as I am aware, very little is known about juvenile and sub-adult movements. Such an important aspect of the biology and data for population demographics remains unanswered. We have a few indications from ringed eagles which have been recovered dead, but I hope that all of the ringing taking place will set up an excellent population study for a student in the year 2020! Crowned eagles take 4 to 6 years to reach breeding age, and over the last two seasons I have ringed 39 Crowned Eagles. The use of solar-CCT or other such long-life telemetry would be of great value for the project however this is particularly limited by the expense of the units and funding availability.

Did you find any interaction or competition with other raptors?

Yes other raptors, particularly Black Sparrowhawks and Fish Eagles (both also successful urban adapters in Durban) have been known to use Crowned Eagle nests, and vice versa. Most surprising is the nuisance that Egyptian Geese proved to be. It is quite well known now that ‘Gyppo’s’ are able to usurp Black Sparrowhawk nest – but it was surprising to see them holding ground against Crowned Eagles! Just days after the juvenile at Zimbali fledged, the geese moved in! The geese held their ground, and while the adult eagles continued to deliver food to the nest, the geese immediately dumped that meat to the ground and the young eagle had to settle with sweeping it off the floor. 40 days later the 7 ducklings hatched and soon jumped to the ground and moved off to the nearest pond.

 Egyptian Geese protesting at an unseen eagle

The pair of Egyptian Geese protesting at an unseen eagle to the left. Photo by Shane McPherson (nest camera).

 

What are the main natural mortality causes for Crowned Eagles in the study area?

Unfortunately I haven’t discovered any mortalities that have been of natural causes. The mortality so far includes electrocutions and gunshot. One adult male while apparently chasing monkeys in the suburbs, flew into the wall of a house at 4am and broke his neck! Others eagles have been rehabilitated after poisoning, and collisions with vehicles. All of these mortalities are effected by human causes in some way.

How is the population doing in your study area?

This requires more work. Hopefully with all the ringing and future resightings we might learn something about the population structure. A couple of cases lead me to suggest that the population is limited by available nest sites in this urban landscape and that there are non-breeding drifters in the population. In particular, the above case of the adult male colliding with a wall at 4 am last March – by June the female there has already attracted a new male. They promptly started building a new nest and I observed them mating last week.


What do you see as the main threats for Crowned Eagles in your study area and the rest of South Africa?

I suspect that the urban landscape is quite stable at this stage. The DMOSS areas are protected from further housing development as they provide many important ecosystem services. It is important to provide balanced data when the public and press get hold of dramatic pet-attack stories. The continued availability of urban wildlife like hyrax, ibis, duiker and monkeys are also important locally. Further afield in South Africa there are plenty of well management forests, reserves, and game farms where crowned eagle populations appear quite secure. In contrast, from what I have read and heard from Africa north of the Capricorn line, the majority of the Crowned Eagles range is under severe threat on a large scale.

Where should future research look at in South Africa and across the whole continent?

Crowned Eagle studies are well represented in South Africa, a peripheral part of their range. I worry most for the huge areas of congo basin, west African and east African parts of the Crowned Eagle range being decimated by mining, deforestation, bushmeat industry, and direct persecution and conflict. The Crowned Eagle is one amongst many iconic species that can ‘speak for the trees’.

 

Shane McPherson climbing to an eagles nest

Shane McPherson climbing to an eagles nest with full protective gear. Photo by Burkhard Schlosser, October 2012

 

An x-ray image of the juvenile eagle from the 2011 Roberts Road nest site

An x-ray image of the juvenile eagle from the 2011 Roberts Road nest site. The bright mark is a 0.177 air rifle slug embedded between the skull and c1 vertebrae. Photo by Shane McPherson.

How do you study the birds?

Often it seems like I spend much more time sitting in Durban traffic than watching the birds! There are just so many nest sites to get around and survey every fortnight, and access to most nests requires very little trekking. For example I can check three nests while driving the highway towards the city centre, and a number of other nests from certain parking spots without opening the car door. On a long summers day I could survey 9 nests. At other nests I have the opportunity to explore the depths of the urban reserves on foot and thoroughly enjoy the diversity and richness that can be found within the city.

The other major part of my study activities was the successful use of camera traps to record breeding behaviours and prey. 11 nests were monitored with cameras using time lapse photography. By the end of the study I had collected over 800,000 images and recorded 1,200 days of dawn-to-dusk time-lapse recordings! These cameras were all placed within about 3 meters of the nest and I have used fixed-rope climbing to get to the nests (between 10 and 35 meters up). Fortunately because of the rope in the way, and the eyes in the back of my helmet, I did not get hit by any of the female eagles, despite their reputation to defend their nest vigorously.

What was your most amazing experience with Crowned Eagles?

I am finding it very difficult to identify one particular moment. The most wanted experience is to observe a successful hunt. Currently though I am thrilled with the project as a whole and especially enjoy being close to the birds in three ways:
1. At several urbanised sites the eagles have become very accustomed to normal activity around their nest. For instance dozens of people stand at the balcony of the Fairmont lodge restaurant at Zimbali Coastal Resort. There you can observe the eagles, their nest and any chick tending activities at eye-level just 30 meters away.
2. Although invasive, climbing the nest trees to service cameras and ring nestlings has also provided a different experience of closeness. Crowned Eagles are notoriously known for their nest defence strategies and I have had the adrenaline pumping pleasure of looking face to face with a monstrous female eagle as she fixes her gaze and approaches on a steep glide towards me. In the very last instance I duck my head and expose the painted ‘eyes’ on the top of my riot helmet and feel the rush of air push down on me as she pulls up and over.
3. As scientist we are supposed to observe objectively. However I cannot help but get attached to many of these young eagles reared in my study area. Some more than others, especially if they have been under the extreme scrutiny of a nest camera study. Almost all juveniles have been colour-ringed as nestlings or fledglings and they are seen for months around their nest site, post-fledging. It is amazing for me to feel so thrilled every time I resight one of the ID tagged eagles. Equally passionately felt are the losses, and there have been tears over eagles recovered shot or electrocuted.

Juvenile African  Crowned Eagle

The origin of that Voortrekkers expression “jy kyk my skeef”? Jacques Sellschop is a talented photographer with exceptional patience. Having spent endless hours over the last three years at the San Lameer nest site Jacques has got to know the birds rather personally and has a special talent of capturing the character of the subject in every image. Photo by Jacques Sellschop, March 2014.

 

 

Shane, Many thanks for answering our questions.

 

Interview by Markus Jais.

→ 1 CommentTags:

New interview with Johann Knobel about the eagles in Africa

January 13th, 2014 · Interviews

Johann Knobel
I met Johann Knobel on our last day during a 3 week Africa raptor trip in January 2012. He was our guide on the last day and helped us find a Little Sparrowhawk and an Ovambo Sparrowhawk and a very unusually marked Booted Eagle. Later we drove to the Johannesburg Botanical Garden to watch African Black Eagles.
It was clear from the beginning that Johann is very passionate about raptors and has a vast knowledge, particularly about eagles. I was very happy to learn that he was working on a book about African Eagles at that time and I immediately asked him to do an interview about the book and African eagles once the book is finished. The book is now out (see the book’s website at: Eagles of Africa) and it is a wonderful mixture of stunning pictures and a very informative text covering all African Eagles including rare guests like the Spanish Imperial Eagle.
Read this interview to learn more about the book, the work behind it and to learn more about eagles in Africa. Many thanks to Johann for agreeing to do the interview.

Markus Jais, Germany, January 2014.

 

 

What is your book all about?

It deals with the 26 eagle species occurring on the African mainland. I try to show just how beautiful and impressive they are, and to tell the story of how utterly fascinating their lives are. Each species is introduced in its own essay with photographs showing various plumages and age groups, and including many action pictures. The species accounts are followed by essays on the hunt, the breeding cycle, the eagle’s day and the eagle’s world. I have tried to combine photographs and text in a way that would make the eagles of Africa accessible and interesting to any reader, from confirmed eagle-watchers right through to people who have not yet seen an eagle in the wild.

How did you get interested in eagles?

When I was a child, many family holidays were spent in the Kruger National Park, which is an eagle paradise. But the single most life-altering influence in this regard was the publication of Peter Steyn’s wonderful book Eagle Days in 1973, when I was eleven years old.

What are the challenges when photographing eagles?

Approaching them sufficiently closely to get a useful picture is often difficult. And to me, it is important to obtain images of their behaviour as well, to show how they live, in addition to producing pleasing portraits of static birds. Flying eagles can be tricky to photograph, and hunting eagles can be particularly elusive. If one is building a collection of photographs for a book on eagles, all the sky backgrounds become repetitive, and it becomes a challenge to photograph at least some eagles against more varied backgrounds.

In Europe most eagles are shy. Are African eagles more approachable?

This varies between species, and often also between individual members of a species. In the parts of Africa with which I am most familiar, one should also differentiate between protected areas and unprotected areas. In national parks and reserves, many eagles are habituated to vehicles, and provided one stays inside the vehicle and behaves with common sense, one can frequently approach these birds very closely. This is fantastic for viewing and photography, and for this reason much eagle photography in Africa is vehicle-based. In some well-known tourist areas such as the Okavango Delta in Botswana and the Rift Valley lakes in Kenya, African Fish Eagles are accustomed to be fed by tourist guides, again providing great opportunities for close views and photography, typically from a boat. Outside protected areas, eagles are generally much shyer, although I have known many exceptions to this rule. For instance, on the east coast of South Africa, two African Crowned Eagles have been nesting very close to the entrance gate of a popular golf and holiday estate for several years. The nest tree is right next to the main access road, and every day, countless motor cars and pedestrians pass the nest at close range. Lawnmowers, weed-cutters and maintenance equipment often raise noise levels far beyond what I find bearable, and yet the eagles are quite habituated to all of this.

What was the most difficult picture to get that’s in the book?

I think I should split the answer up into three parts:

First, the species that was the most elusive: the Ayres’s Hawk-Eagle, or Ayres’ Eagle. I had to wait and wish many years for an opportunity to take decent photographs of it. In an ironic but happy twist of fate, I obtained my best shots of the Ayres’ in Pretoria, where I have lived all my life, at the eleventh hour as the production of the book was drawing to a close.

Second, I also had to wait very long to get pictures of certain kinds of eagle behaviour. Mating comes to mind as a particularly difficult activity to photograph. In the end I obtained reasonable shots of Black-chested Snake-Eagles mating, but within three months of Eagles of Africa reaching the book shops, I took better pictures of African Hawk-Eagles mating. Getting a photograph of an eagle bathing also eluded me for an incredibly long time. Eventually I got lucky with an African Fish Eagle bathing in the Letaba River in the Kruger National Park.

Third, the photographs for which I suffered the most: a comparatively common species, the Wahlberg’s Eagle, at its nest. Through the generosity of the well-known South African ornithologist Warwick Tarboton, and our mutual friend Mich Veldman, I could use a hide on an eight-metre high aluminium tower to photograph a very photogenic Wahlberg’s Eagle nest. This particular pair was special because the male was a dark morph bird and the female was a pale morph one. The only problem was my fear of heights. Sitting in the apex of that wobbly structure, with Eurasian Bee-eaters catching flying insects far below me, scared the living daylights out of me. I have the greatest admiration for bird photographers who do that kind of thing as a matter of routine.

What are the main threats to eagle conservation in Africa?

The most serious threats are similar to those faced by eagles in many other parts of the world: habitat destruction; depletion of the prey base; direct persecution; and indirect poisoning (where poisoned bait is left for other species such as jackals, caracals, feral dogs or leopards). Electrocution and collision with electricity structures are also factors in some areas. South Africa will see the introduction of many wind farms in the near future, and these will inevitably claim some eagles. Ornithologists have been involved in planning and impact studies from an early stage, and we hope that this will mitigate the impact on birds. A massive wind energy project is planned for Lesotho, and our main concern here is for highly threatened Bearded Vultures and Cape Vultures, but some eagles may also be at risk.

In South Africa, three eagle species have, in particular, suffered alarming range reductions and/or reductions in numbers: Bateleurs, Tawny Eagles and Martial Eagles. Carrion is an important food source for Bateleurs and Tawny Eagles, and the decline of these two species is probably mainly related to their finding and eating poisoned bait illegally put out for mammalian predators. Martial Eagles have traditionally been suspected as lamb catchers, and their decline is probably mainly related to direct persecution. Of the African resident species, the Southern Banded Snake Eagle has the smallest distribution range. It is basically restricted to a thin strip of tropical bush on the African east coast, and is therefore very vulnerable to habitat destruction. The Sahel savanna habitat of the Beaudouin’s Snake Eagle is also under pressure, and this species is listed as Vulnerable in the IUCN Red List, which makes it the resident African eagle species with the gravest Red List status. The other species I have mentioned here are all classed as Near-threatened, except for the Tawny Eagle, which is still of Least Concern on a continental and global scale.

A threat to vultures, in particular, is targeted killing by lacing carcasses with poison, either to obtain vulture body parts for use in traditional medicine, or to mask the activities of ivory poachers, who worry that the presence of vultures in the skies will reveal the whereabouts of their illegal activities. Scavenging eagles also succumb to such vulture-targeted poisonings.

What is the most endangered eagle species in Africa?

Of the species breeding in Africa, I would think that the Beaudouin’s Snake Eagle and the Southern Banded Snake Eagle are the most vulnerable. However, we should keep a close watch on all five eagle species mentioned in the previous answer, and just recently the African Crowned Eagle has also been up-listed to Near-threatened by BirdLife and the IUCN. Big savanna parks and wilderness areas still hold appreciable numbers of Bateleur, Tawny Eagle and Martial Eagle, but some evidence is emerging that populations in protected areas may not be quite as secure as we may have hoped for. Very little information is available on the Congo Serpent Eagle and the Cassin’s Hawk-Eagle, but they are not suspected to be in trouble in the shorter term. As you well know, there are concerns about some of the migrant eagles that visit Africa from Europe and Asia, with the Eastern Imperial Eagle and the Greater Spotted Eagle immediately coming to mind. The rarest of all the eagles on the African list is certainly the Spanish Imperial Eagle. Although it was historically a breeding resident in Morocco, it is to the best of our knowledge only a rare non-breeding vagrant to Africa at the moment. One can only hope that Spanish conservation efforts will eventually prove so successful that more Spanish Imperial Eagles will once again venture into Africa.

What do you think should be done to secure the future of the eagles in Africa?

In an Africanraptors.org interview with Alan Kemp about the conservation of the Martial Eagle, Alan said that the most important step is to maintain as many large pristine or near-natural areas as possible, and I agree whole-heartedly with this. In Africa we are blessed to have some magnificent parks and wildernesses, and most of them are well-populated by eagles. However, much of Africa is densely populated by humans, and setting aside protected land can only be part of the answer. We also need to mitigate threats to eagles where they range outside protected areas, to address aspects such as direct persecution, poisoning, and habitat destruction. Migratory species pose special problems, and the Memorandum of Understanding on Migratory Birds of Prey in Africa and Eurasia, established in the wake of the Bonn Convention on the Conservation of Migratory Species of Wild Animals, is aimed at addressing these problems. The law can play an important part in the conservation of raptors, and I have embarked on research on how the law can be used more effectively to protect raptors in Africa, with the emphasis on eagles. Many people tend to think that the most important role of the law in nature conservation is to punish people for transgressions, but the law can also provide for positive actions that can benefit eagles and other wildlife, such as creating protected areas, and mandating and facilitating environmental impact studies and biodiversity management plans. Environmental laws can also help to inculcate a culture of respect for, and national pride in, the natural heritage of a nation. The most inspiring example for all of us is probably a European one, namely the holistic and creative use of European Union laws and Spanish laws to initiate and facilitate the conservation of the Spanish Imperial Eagle. On the other hand, over-regulation is also a danger that must be guarded against. In South Africa, a very positive conservation initiative is the cooperation between the national electricity supplier and the Endangered Wildlife Trust to mitigate bird mortalities on electricity structures, and this was entered into voluntarily with no legal coercion. The Endangered Wildlife Trust also does wonderful work to promote favourable attitudes towards eagles in farming communities. More important than achieving compliance with the law, is changing the hearts of people, of winning human friends for the eagles of Africa.

Most news about wildlife conservation in Africa is currently about Elephants, Rhinos and Lions. This is of course important, but do you think that eagles don’t get enough press?

I would agree with that, but I should also openly declare my bias as an eagle fanatic. Rhinoceros poaching is really a national crisis in South Africa at the moment, and it is understandably taking the limelight. Of all the raptor groups, the greatest concern is for the vultures. The outlook for them is bleak, as they are highly mobile, and poisoned carcasses can kill large numbers of them even though they may, for instance, breed inside large national parks. Conservation NGOs like the Endangered Wildlife Trust are doing great work to inform the public about the plight of vultures. Eagles tend to play second fiddle to some extent, and I can understand this very well, but I would like to see them getting more publicity.

How can eagle photography help protect the birds?

Great question! If people love eagles, they want them to be protected. Many people seldom, if ever, see an eagle really well, and how can they love something that they do not know? Eagle photographs have the potential to bring eagles closer to such people. Just the other day, someone who paged through my book remarked that she had never known that eagles were so beautiful. Eagles really need human friends today. I hope that eagle photographs, eagle books and films, and websites such as this one and the Global Raptor Information Network and the europeanraptors.org site, would be able to win more human friends for the eagles and other raptors.

How should a responsible bird photographer behave in the field in order to not disturb or harm the eagles?

If the photographer loves the birds more than photography, he or she will usually intuitively do the right things. It is important that one’s desire to obtain a certain photograph does not overshadow one’s sensitivity for the well-being of the eagle. Photography at a nest brings with it a special responsibility. I am not aware of any African laws prohibiting photography of birds of prey at their nests, unlike the position, for instance, in some European jurisdictions. The photographer’s conscience must therefore be the guide to proper conduct. If an eagle pair does not accept the presence of a photographer or a hide/blind near the nest, the photographer must abandon the attempt at photography and leave the birds in peace. Also, one should never erect a hide/blind in a spot where it is likely to attract the attention of humans who may intentionally or inadvertently disturb the breeding birds. Away from the nest, the stakes are not quite so high, but one would do well not to chase an eagle off its hard-won prey, or to disturb it in its night-time roost. In Africa, the larger national parks and game reserves give the photographer the opportunity to photograph many eagle species, and provided the photographer heeds the rules applicable in the park, and uses common sense, the potential of serious disturbance to the eagles is small.

Do you have some tips for bird watchers and nature photographers who want to take stunning images of eagles?

This ties in nicely with the previous question. I think the best advice is to love your subjects, the eagles, more than your equipment and the photographic process. I believe that that kind of dedication will shine through the photographs in the end. All the usual nature photography tips about good light, composition and backgrounds are relevant to eagle photography, although eagles often make things difficult by exhibiting the most interesting behaviour in the hottest part of the day when the light can be very harsh in many parts of Africa. One thing that many photographers overlook when photographing perched raptors, is the pose of the bird. An eagle just standing there, although it is a magnificent creature, can make a rather boring photograph. Wait for it to be alert on sighting prey, or before taking flight, because then it will often stand in a bolder and more photogenic stance. An insider tip already known to many bird photographers, is that an eagle will often defecate before taking flight, and this can be the photographer’s cue to be ready for a burst of action photographs.

A very personal thing: I do not like the look of many photographs of eagles where electronic ‘fill-flash’ was used to supplement natural light. The flash tends to eliminate the small shadow under the heavy ‘eye-brow’ of the eagle, and this often results in the eagle looking startled instead of fierce. To me this robs the photograph of its soul. l prefer to use natural light only, and to lighten the shadows somewhat in post-processing.

People are always interested in other photographer’s equipment. What do you currently use?

I am a somewhat conservative equipment buyer, and I ‘upgrade’ my eagle experiences far more often than my equipment. I estimate that roughly a third of the photographs in Eagles of Africa were taken with film cameras, but these days I use digital cameras only. I use two DSLR camera bodies, and both are so-called ‘crop-frame’ rather than ‘full-frame’ cameras. The full-frame bodies are known to produce superior image quality, especially in low-light situations. However, I usually find my subjects in bright light, and my main challenge is usually the ‘reach’ of my lenses. In such situations, the crop-frame bodies seem to work very well. For flying eagles, I usually use a 300 mm lens, more often than not in conjunction with a 1.4x converter, and I prefer to hand-hold the camera to follow the movement of the target. When working from a vehicle, I often prefer a fast 300 f2.8 lens, but I also use a much smaller 300 f4 lens if portability is a priority. I use an old 600 mm lens for perched birds, birds on nests, and birds that are taking off or alighting. The 600 mm lens is also often used with a 1.4x converter, and is always supported on a bean bag or a tripod.
.

Do you have a favourite place to photograph eagles?

Yes, the Kruger National Park. I have loved it since my childhood holidays, and it remains the only place where I have managed to see 10 different species of eagle in a single day. However, the Kgalagadi Transfrontier Park is stiff competition from a photographic point of view, as it has the advantages of a greater percentage of sunny days and more open terrain, making action photography easier. Neither the Kruger nor the Kgalagadi is good for photography of some of the most spectacular eagle species, for instance the (African) Crowned Eagle, and Verreaux’s (African Black) Eagle, so there is always a need to visit other special places too.

Do you have a favourite eagle species?

Yes, my favourite eagle species is the one I am looking at through my binoculars or camera at any given moment.

What photography plans do you have for the future?

After completing Eagles of Africa, I told my wife that I really looked forward to be less obsessed with eagles and to enjoy photographing other birds and wildlife again. We went to the Kgalagadi soon thereafter, and guess what? As soon as we began to find eagles, all other species paled into insignificance. So I guess my photography plans are to photograph as many eagles as possible without the pressure of trying to fill the pages of a book.

How do you see the future of eagles in Africa?

As Alan Kemp said in his interview, the real challenge is how to conserve raptor and raptor habitat in view of the needs and aspirations of the growing human population of Africa. This is indeed a daunting task, but we shall not be able to make a difference for the eagles of Africa if we are paralysed by pessimism. Certainly there is a lot to feel gloomy about, but Africa is still a great continent for eagles. We must be neither despondent, nor complacent. We must be vigilant, and we must be positive that we can make a difference for the magnificent winged predators of Africa. Ultimately, I believe, the children of the African people will also be happier if the African skies are still graced by soaring eagles.

What was your most amazing experience with eagles?

Watching the tiny bill of a Verreaux’s (African Black) Eagle chick breaking through a tiny hole in an egg was a highlight. I like to think of that experience as having witnessed the birth of an eagle. Watching the breath-taking aerobatics of displaying Booted Eagles and hunting Ayres’ Eagles has also been exhilarating. A thousand Lesser Spotted Eagles congregating at a nesting colony of Red-billed Queleas in the Kruger National Park was a fantastic spectacle. But the best experience was probably finding an exceptionally confiding juvenile Martial Eagle. I could approach it so closely in my vehicle that, every time I took a picture, the eagle turned its head from side to side on hearing the camera shutter. For a change, the eagle appeared to be just as interested in me as I was interested in it! The story is told in the last chapter of Eagles of Africa.

I must add that the people who assisted me in various ways while I was working on Eagles of Africa, were also truly amazing. Many special friends and landowners were astoundingly helpful and hospitable. Many of the well-known ‘eagle people’, from Africa and abroad, also helped me: Alan Kemp (mentor and scientific adviser), Peter Steyn (inspiration, mentor and writer of the Foreword), Bill Clark, Rob Davies, Dick Forsman, Rob Martin, Rick Watson, and many others. To have shared in their knowledge and experience so freely, was also an amazing experience. Finally, I would like to say thank you, Markus, for helping me with advice on where to find the Spanish Imperial Eagle while I was still working on my book, and for this opportunity to talk about the eagles of Africa on your website.

Thank you Johann for answering all the questions!

To learn more about the book, see here:
Eagles of Africa

→ No CommentsTags:

Interview with Chris Bowden and André Botha about vultures in Asia and Africa and the IUCN Vulture specialist group

September 13th, 2013 · Interviews

1) Where do you work and what do you do with vultures?

Chris: I am based at RSPB Headquarters in Sandy, England, although shifting later this year to live in Bangalore, India, but still working for RSPB with the same remit. My role is channelling RSPB support and wider coordination of efforts to conserve the critically endangered Gyps vulture species in South Asia, primarily in India but also in Nepal and the region.
Andre: I work for the Endangered Wildlife Trust in OSuth Africa as the Manager of the Birds of Prey Programme and am the Co-chair of the IUCN SSC Vulture Specialist Group.

2) You are co-chair of the IUCN vulture specialist group. What exactly is the Vulture SG and what does it do?

Chris: This is a newly established umbrella and I share responsibility with my co-chair Andre Botha who is in South Africa. Between us the main priority is to ensure there is a meaningful network and ownership of the real threats that vultures are facing globally, but with a strong emphasis on Asia and Africa where the threats are currently most apparent. Because of the recently established SAVE (Saving Asia’s Vultures from Extinction) consortium www.save-vultures.org (do have a look at what we are doing) for Asia, the VSG has a greater role to play for Africa where no such network exists, but where threats are also increasing. An early issue to tackle is ensuring that the threats are sufficiently clearly identified before putting full force behind implementing the activities required to address those threats. At least in Asia, the main threat is very clear, ie diclofenac, and most of my time is spent directly or indirectly addressing the actions needed to counter this threat. The Vulture SG does also have a wider and global remit in reviewing the red data book status of all 23 vulture species, and may also have a greater role to play in future outside Africa and Asia as it develops. Meanwhile it is a network and a framework that communicates with its members every few months, but we plan to develop a web presence and a stronger presence more widely in future.

3) You have been involved in raptor conservation in India after the dramatic decline of several gyps vultures there. How is the current situation in India and neighbouring countries?

André Botha with a Lapped-faced Vulture

André Botha with a Lapped-faced Vulture

Chris: Having been so close to the issue now for over nine years, it was just last year that I feel we really turned a corner for these species. Having at least halved the diclofenac use by vets, the real sign of progress was the 2011 surveys (India and Nepal) which showed that the declines for all 3 Critical Gyps species have significantly slowed. Similar figures also came through from Pakistan at the same time. The ongoing problems are that despite the legislation, human diclofenac is still being (illegally) used by vets, and the packaging is too convenient. I’m determined that we can stop this. The other issue is other NSAIDs coming on to the market as replacement drugs which may also be unsafe (and we know some are!).

4) Is diclofenac also a problem for non gyps species?

Chris: There has been testing of Turkey vultures (obviously a distant relative) and this proved not to be susceptible. Meanwhile we dont have evidence either way for several other key species so we simply don’t know the answer. This is some more information on this which should be published very soon I hope which unfortunately does suggest that some non-Gyps species may be susceptible… and we have confirmation that five of the Gyps species definitely are highly susceptible and worryingly that other NSAIDs that may replace diclofenac eg ketoprofen are also dangerous to them..

5) Are there alternatives for diclofenac available?

Chris: There are several alternatives, but only one so far that we know to be safe for the vultures – ie meloxicam. Others coming into the market are at least in some cases also unsafe so this is a major worry which we are also working to address.

6) What are the ecological consequences of the dramatic vulture decline and how does this affect humans?

Chris: There are multiple consequences, as we all know the role of vultures in disposing of rotting carcasses. A conservative estimate is 10,000 tonnes/year of meat is no longer consumed by the vultures that have already gone!  Feral dog populations have certainly increased significantly as one consequence, and are the main vector for rabies. Anthrax has almost certainly also increased, but the main consequence is the issues surrounding having more rotting meat and the environmental pollution of water sources, the smell and other hygiene-related issues. There have been some studies of the economic impact and there are plans to do more on this, but unfortunately it has so far proved very difficult to get a full clear picture of the impacts that is fully scientifically robust, but that certainly doesn’t mean that these impacts are anything other than enormous.

8) Can something like in India also happen in Africa?
Chris: Diclofenac has appeared in the veterinary market in Africa which is very worrying and something that needs constant vigilance in all African countries to prevent it taking off on a wider scale. Having said this, it may not have quite the same scale of impact due to the lower dependence of African vultures on domestic livestock, but we can’t be complacent on this since even in countries where meat is widely consumed compared to India, the declines of vultures due to diclofenac use have been dramatically quick (I’m thinking particularly of Pakistan).

9) What is the overall situation of vultures in Africa? Which species are the most threatened and are the species that are doing well?

André: The situation in Africa is rather dire and there are some conservationists that consider the rate of decline in vulture populations in some parts of Africa comparable to that of Asia in the last decade. Three species, the African White-backed- and Hooded Vulture as well as the Rüppell’s Griffon were up-listed to “Endangered” on the IUCN Red List of Threatened Species in 2011 and 2012. The only species that is believed to be doing better in Africa is the Palm-nut Vulture.

10) From an ecological point of view how important are large predators like Tigers, Leopards or Dholes in India and Lions, Leopards, Cheetahs or Wild Dogs as providers of carrion in Africa for vultures?

André: In Africa, large predators still play an important role in the provision of carcasses for vultures to feed on, but due to the fact that most of these large predators are restricted to protected areas, the role that they are playing have diminished and has also led to a decline in available food for vultures over time.

11) How does the decline and persecution of these large predators affect vultures?

André: It has certainly reduced the availability of food for vultures to the extent that supplementary feeding sites were introduced in southern Africa to provide safe and reliable food for the birds to feed on. There is little doubt that there sites have made a significant contribution to sustain vultures in areas where large predators have disappeared.

12) Do vultures suffer from a decline in large mammals like deer, antelopes, elephants and others that provide carrion?

André: See above.

Chris: In Asia vultures have adapted to exploit the increases in domestic livestock which have largely coincided with the declines of wild ungulates and predators. But they do depend on those livestock being available to feed upon, so such declines make the vultures more sensitive to human-livestock practices.

13) How important is traditional livestock farming for vultures and are there conflicts with farmers?

André: There are recorded incidents of conflict with small livestock farmers in particular where species have been known to attack ewes weakened after giving birth and lambs also being taken shortly after birth. Some farmers have also complained about vultures “taking over” drinking troughs for bathing and socializing whereby stock and game can be deterred from using a particular drinking site. These incidents are however few and often linked to extreme conditions such as droughts, etc. There are many parts in Africa where vultures feed almost exclusively on livestock carcasses and it can be argued that some populations are entirely dependent on stock farming for food.

14) What other threats do exist for vultures in Africa?

André: Apart from the obvious danger of poisoning in its various forms, energy infrastructure such as power-lines and pylons have had a substantial impact on vultures populations and the planned development of large-scale wind-energy projects in various parts of Africa has raised concerns that vultures in Africa will be severely affected by these if these and other large soaring birds are not considered when decisions are made on the siting thereof. A major concerns which also impacts on African vultures is the use of vultures in the muthi/jiju trade, live trade and even as a source of food in certain parts of West Africa. It is believed that declines in many parts of West Africa can be ascribed to this and there are also concerns that populations in certain parts of southern Africa may become locally extinct due to the harvest of birds for these purposes.

15) Are vultures doing better in large protected areas?

André: Large protected areas in Africa do seem to provide a safe-haven for many vultures, especially in terms of breeding and due to the availability of food in the form of carcasses provided by large predators. These birds do however regularly venture outside of protected areas when foraging and are still at risk to the range of threats discussed earlier.

16) What is needed for the long term survival for vultures in Africa, Asia and other parts of the world?

André: As with most conservation initiatives, it is imperative to create awareness and garner support from people at all levels of society who may impact on vultures through their activities. In an African context, a Pan-African Vulture Strategy has been published following the Pan-African Vulture Summit in Kenya in April 2012 which provides a framework for appropriate conservation action to ensure the continued survival of vultures in Africa. This largely depends on the cooperation of a range of stakeholders and is dependent on the support of decision-makers at government-level across the continent. Without the support of the majority of stakeholders, it will be difficult to stop the current decline in vultures on the continent.

17) What gaps in our knowledge about vultures do still exist and where should research focus on in the coming years?
Chris: Asian vultures are not well studied, and better documenting home-range and feeding ecology is needed for all of the species. But the most immediate concern is (assuming diclofenac is removed comprehensively) checking that other veterinary drugs coming into the market are safe for the vultures, and dont threaten to exacerbate the already critical situation.

André: The same applies to Africa where we also have substantial gaps in terms of knowledge of vulture population status and threats facing birds at present. There is a lot of work that needs to be done in similar areas to those mentioned by Chris.

18) Some people give up on conservation because of so many negative news for so many species.
What keeps you optimistic and why do you keep fighting for the conservation of vultures?

Chris: I have to concede that this issue has been a tough one, and even some of the conservation community particularly some from within the region have been quite hard to bring onside. But along with that challenge it has been very rewarding when more people have joined the efforts to address the main issues, and especially over the past two years it has become much easier to see that progress is being made. The staff and teams on the ground at BNHS and BCN in particular, as well as RSPB and SAVE colleagues have pulled together and kept going regardless and I think we all draw inspiration (I know I do) from that.

19) What was your most amazing experience with vultures?

Chris: I think that seeing the first ever small chicks of oriental white-backed vultures at Pinjore, Haryana to be artificially incubated and hand-reared and again seeing them fledging was very rewarding, knowing that we can breed them and improve productivity which all adds up to a viable programme for reintroduction to the wild. Watching the downy chicks taking the meat offered to them and start to feed themselves was really something.

 

→ No CommentsTags:

Interview with Ralph Buij about the Grasshopper Buzzard

April 28th, 2013 · Interviews

Ralph Buij (1976) is a Dutch biologist who obtained his MSc at the University of Utrecht in 2000.  His thesis subject was the behavioural ecology of the Sumatran orangutan. Following further wildlife studies and work in South Africa and Gabon, Ralph took over the coordination of the University of Leiden’s research programme at the Centre for Environmental and Development Studies in far northern Cameroon.  While in that position from 2006-2010, he carried out the field work for his PhD thesis, which led to the successful defence in January 2013 of ‘Raptors in changing West African Savannas.  The impact of anthropogenic land transformation on populations of Palearctic and Afrotropical raptors in northern Cameroon’.   One very commendable aspect of the thesis is that both Afro-tropical and Palearctic raptor species were studied.  Key species reported on include Pallid Harrier, Grasshopper Buzzard, African Swallow-tailed Kite and Dark Chanting Goshawk.”  Ralph’s wife Barbara Croes is co-author on four of the chapters.

Joost Brouwer

Ralph Buij with Grasshopper Buzzard nestling

Ralph Buij with Grasshopper Buzzard nestling

 

1) What is known about the current status of the Grasshopper Buzzard in Africa?

The Grasshopper Buzzard is found in a savanna belt south of the Sahara, between Senegal and Ethiopia. Some parts of the breeding range are as narrow as 400 km wide, and Grasshopper Buzzards venture south of the equator only in east Africa and during the non-breeding season. Little is known about the abundance of this raptor in countries that cover extensive areas within the range (Sudan, Nigeria, Mali, Chad), but the Grasshopper Buzzard is among the most common raptors in the well-studied areas of the distribution range. In our study area in northern Cameroon, which encompassed the breeding and non-breeding range, circa 1 out of every 10 raptors recorded along road transects was a Grasshopper Buzzard. We counted averagely 30 individuals/100 km in the low-lying grasslands of the Lake Chad Basin, where productive and partly flooded grasslands produce an abundance of prey. Sclerocarya birrea woodlands on higher ground support high breeding densities. Only Black Kite (“Yellow-billed Kite”) and Hooded Vulture were more commonly encountered in northern Cameroon.

Adult and immature foraging on alate termites

Adult and immature foraging on alate termites

 

2) How has the population developed during the last decades?
Populations appear to have decreased the past forty years in both western and east Africa. The savannas in large part of the distribution range are under pressure from some of the highest human population densities on the continent. In the cultivated areas of central West Africa, J-M Thiollay counted fewer than half the numbers along transects in 2003 compared to 1969. But population trends are tricky to evaluate in such a mobile species and numbers may vary quite considerably in any area within periods of weeks or even days. It would be very useful to have longer-term monitoring programs in place, with regular surveys, to evaluate current population trends of this and other raptors that depend on the arid sub-Saharan savannas.

 

Adult with snake alighting at nest

Adult with snake alighting at nest

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

It all depends on the extent of land clearance for cultivation, because breeding density decreases with extensive tree clearance and expanding cultivation. Population declines appear to have been less severe inside protected areas. We found that breeding Grasshopper Buzzard adapted quite well to moderately cultivated landscapes in northern Cameroon. For example, we found no significant difference in reproductive output between pairs breeding in protected and non-protected areas. Grasshopper Buzzards breeding in agricultural habitat experienced lower predation rates and some accepted heavily pruned trees for breeding as shown on the photo. Some prey animals, such as reptiles, are more easily accessible in transformed habitats which may compensate for a decrease in the abundance of other prey populations.

 

4) What is the preferred habitat of the Grasshopper Buzzard?

This depends on the time of the year. They use open woodlands in Sudano-Sahelian savannas for breeding at the transition of the dry and wet seasons and migrate northwards into Sahelian grasslands and thornbush after breeding. They subsequently move southwards again into denser Guinea savanna woodlands in western Africa. Grasshopper Buzzards can be quite common in cultivated habitats even when breeding and when they exploit alate termites and ants after rains.

 

Flying adult

Flying adult

5) What is known about movements of adult and immature birds?

Both vacate the breeding area soon after breeding- when rains stimulate grass growth and rapidly reduce prey accessibility – and move north to exploit a flush of insects with the rains. There is a shift in the start of the rainy season in western Africa, with rains starting later at higher latitudes, so Grasshopper Buzzards sort of ride a wave of rains and an abundance of insects to northern latitudes. The entire population that moved northwards in July-August, gradually returns southwards into the Sudano-Guinea savannas when the rains have stopped, following increasing prey availability as a result of fires and grazing. The timing and extent of these movements have been well described by Jean-Marc Thiollay, as has their relationship with insect availability. In a way Grasshopper Buzzards and African Swallow-tailed Kite replicate movements by Palearctic migratory raptors, but at a smaller scale. Grasshopper Buzzard populations largely remain south of the main winter range of the Palearctic migrants, which also shifts southward over the course of the dry season. When Grasshopper Buzzards move north to breed in the Sudano-Sahelian woodlands, most Palearctic migrants have already departed to breeding grounds north of the Sahara.

Immature hunting near a fire

Immature hunting near a fire

 

6) What is the preferred prey of Grasshopper Buzzards?

Grasshopper buzzards are primarily grasshopper specialists during the non-breeding season. They consume a range of insects, mostly grasshoppers and beetles, also scorpions and sunspiders when breeding, but their breeding season diet is dominated by reptiles in terms of biomass. Other vertebrates such as frogs, rodents, and birds are also regularly taken during this time.

 

Immature Grasshopper Buzzard and Abyssinian Roller on the lookout for grasshoppers fleeing a fire

7) What is known about the conservation status of the Grasshopper Buzzards prey species?

Although small vertebrates and invertebrates that feature on the breeding season diet decline with severe grazing and land transformation, Grasshopper Buzzards are opportunists and may switch to other prey to accommodate such changes. In general, their dependence on small prey makes Grasshopper Buzzards much less vulnerable to prey depletion compared to the larger raptors, which compete with humans for preferred “bushmeat” prey (gamebirds, squirrels, hedgehogs, monitor lizards, etc).

 

8 ) What is known about the size of the required territory and home range for a pair of Grasshopper Buzzards?

We found that densities were generally high with up to 3.3 nests per square km and inter-nest distances < 100 m in high-quality habitat. Home ranges greatly overlap and birds regularly pass over neighboring territories on foraging flights. It would be nice to tag a few to get better information on range size and movements, also from different areas in the distribution range.

 

Immature in November

Immature in November

9) Is there competition with other raptors for nesting places or for food?

They breed alongside a number of other small to medium-sized raptors such as African Swallow-tailed Kites, Yellow-billed Kites, Gabar Goshawks, Dark-chanting Goshawk, etc. and most importantly in terms of numbers, other Grasshopper Buzzards. Frequent intraspecific interactions in high-density areas may lower reproductive output, but competition for food is probably limited during the rains when small prey is abundant. Apart from competitive interaction with similarly-sized raptors, direct predation of adults or their offspring by larger raptors may take a heavy toll during the breeding season. Our studies showed that the canopy cover above the nest was positively related to nest success and the number of fledglings, suggesting that concealment of nests lowers predation rates by other raptors. Over the course of the breeding season, Grasshopper Buzzards experience an influx of migratory raptors (Red-necked Buzzard, Wahlberg’ Eagle) capable of killing adults and nestlings. Pairs will fiercely attack passing large raptors and crows, and pairs may join to form a strike force. I once saw a juvenile African Hawk-Eagle tailed by three loudly alarming Grasshopper Buzzard pairs as it flew over their territories. Apart from raptors, nocturnal carnivores also take a toll on nestlings and breeding adults. When mammalian predators are sighted during the day they are also vigorously attacked – we once saw a Serval being attacked by a pair of Grasshopper Buzzards who took turns dive-bombing the cat. In the end the Serval made a run for it.

 

Juvenile in August

Juvenile in August

10) How many eggs do Grasshopper Buzzards lay?

The clutch size is 1-3, with averagely 2 eggs laid in Cameroon.

 

11) What is known about the breeding success and survival rates of Grasshopper Buzzards?

Not much for such a common raptor in its breeding range. Nest success in Cameroon was around 40%, twice as high as in African Swallow-tailed Kites, another intra-African migrant that breeds in the same habitat during the same time. So far, no work has been done on fledgling survival rates and this will be an important next step. We do have evidence that fledgling condition is compromised in human-transformed vs. natural habitat, and it would be interesting to know whether this affects their survival. Reproductive success may be comparable in natural and transformed habitats but if fledglings have a lower survival rate due to depressed body condition at fledgling, long-term breeding output may still be lower in man-modified habitat. Given the positive relationship between rainfall, food supply, and reproductive output, much may depend on the duration and extent of rains. Some (not all) climate models show that the Sahel is likely to experience a drought period and rains will become more local and erratic. Survival and long-term reproductive output may drop considerably under drought condition and this needs more study.

 

Grasshopper Buzzard nest in a Sclerocarya birrea tree

Grasshopper Buzzard nest in a Sclerocarya birrea tree

12) What gaps in the knowledge about the Grasshopper Buzzard do exist and where should research focus in the future?

I mentioned a few gaps above. It would be very interesting to further examine the relationship between climate conditions and survival rates and reproductive output. We need to assess what factors determine clutch abandonment, whether birds have the ability to re-nest after nest failure, possibly at higher latitudes, and how this influences reproductive output. Also, very little is known about breeding densities outside of Cameroon, mostly because much of the breeding range is in areas little visited by ornithologists. There have been apparent reductions in the number of non-breeding visitors to Kenya and Tanzania, which might be linked to declines further north. The timing and extent of seasonal movements is insufficiently known, particularly in the eastern parts of the distribution range. Finally, locust control operations have the potential to depress this important resource in the Sahel and more studies are needed to investigate and mitigate its impact on these and other insectivorous migratory raptors.

 

13) What are the main threats for the species in Africa?

Like other wildlife, it is most affected by increasingly extensive land-use change by rapidly growing human populations, notably conversion of woodlands into cultivated areas with few trees, and heavy grazing pressure. People may also directly impact breeding populations by harvesting nestlings. We worked in an area where the vast majority of the Muslim population would not eat raptors because of religious conviction, but found that some people with animist and Christian beliefs regularly consumed raptor nestlings.

 

Farmers are terrified of any snake and happy when they see Grasshopper Buzzards catching them in their fields

14) What can and must be done to secure the survival of the Grasshopper Buzzard?

Any measure to minimize the effects of human population growth on the landscape would benefit raptors in western Africa. In most areas, the lack of financial means for investments to improve agricultural yields (e.g. fertilizer) results in rapid soil denudation and loss of natural habitat from destructive slash-and-burn activities. Investments in improved agricultural techniques would benefit people and wildlife. As long as such developments remain localized and few, agro-bushlands are becoming increasingly impoverished and over-utilized. This will affect raptors as well as people depending on the bush for wood, thatch, food, grazing, etc. Grasshopper Buzzards use native trees in croplands for breeding, but many trees are logged or their large side-branches cut, among others to prevent Red-billed Quelea from establishing breeding colonies in them. Queleas can be an important agricultural pest species in this region, and people have limited means of stopping them, apart from using handheld ropes when a flock lands in their fields. In some areas reforestation projects have been initiated but these often use exotic tree species, such as Neem, which are rarely used as nest trees by Grasshopper Buzzards. These trees are valued be local populations because of the medicinal properties of various parts of the trees, but they are ecologically of little value.

Recently fledged individual with a beetle

Recently fledged individual with a beetle

15) Are there any conservation projects for the Grasshopper Buzzard?

None that I know of. Any project focusing on proper agricultural intensification practices with patches of bushland protected from heavy exploitation would also be beneficial to Grasshopper Buzzards.

16) How do you see the future of the Grasshopper Buzzard?

Let’s be optimistic and say that populations may remain stable in the short term in some areas, but the long-term outlook is bleak. Despite still being among the commonest raptors in the region, it is endemic to a region that has seen a crash of raptor populations in only 40 years. Given the predictions of human population growth, and irrespective of the potentially negative effect of climate change, breeding densities and reproductive output will decline further with expansion of agriculture and vegetation clearance. True, other raptors such as larger eagles and vultures are likely to vanish from the region before Grasshopper Buzzards do. Some have already disappeared from vast areas of their former range; Secretary Bird, Martial and Long-crested Eagles, while the large vultures are on the brink of disappearing from many countries in western Africa, if they have not already been “functionally extirpated”. Similar trends in the region have been noted in other apex predators, such as lions, cheetahs, wild dogs. Relationships between park size, human populations and wildlife extinctions inside parks are telling and predict that only very few parks in the region are probably large enough to sustain intact predator populations. In the absence of substantial investments in national park management capacity, western Africa will be the first region where high-profile wildlife species including raptors disappear, even from national park strongholds. In contrast to the larger raptors, Grasshopper Buzzards are less sensitive the human exploitation and likely to persist in parks and agro-ecosystems, but developments in agriculture will determine at what level of their former population size.

 

Nest (circled) in a heavily trimmed Sclerocarya birrea tree

Nest (circled) in a heavily trimmed Sclerocarya birrea tree

17) What was your most amazing experience with the Grasshopper Buzzard?

This is not a fierce hunter, like some of the large eagles or accipiters portrayed here. Still, it has all features of an opportunistic hunter of agile prey, catching grasshoppers in the air and even birds. I recall one situation when I as standing at the edge of a sorghum field, planning to check a nest in an isolated marula tree. While scanning the surroundings for potential nest predators I spotted a Grasshopper Buzzard in the top of another tree 60 m from me. I continued on my way towards the nest but after having walked several meters, I suddenly heard a hard whooshing sound as if something had been thrown at high speed into the foliage of a nearby tree. I looked up and saw the Grasshopper Buzzard hanging upside down in the tree, only 4 meters from where I was standing, clasping a 60-cm snake in its talons. The bird must have seen the snake move as I approached the tree. A struggle followed and I could see the tenacious battle, the buzzard not wanting to let go of such a prize even with the snake coiled around its body and the branches. The bird appeared to be unaffected by my presence, focusing all its attention on the snake. Eventually the snake gave way and the Grasshopper Buzzard flew off with its prey toward the nests, where she started feeding the nestlings. A memorable experience, I was thrilled to see the birds’ determination at such close range, somehow testimony to the resilience of these raptors in an increasingly humanized landscape.

 

 

→ 3 CommentsTags:

Interview with Eric Ole Reson about Maasai attitudes towards vultures

February 6th, 2013 · Interviews

Eric Ole Reson hails from Narok county and recently completed a Masters degree in Wildlife Biology from Clemson University in the USA. He also holds a BSc. In Wildlife Management from Moi University, Eldoret. In this interview, Eric interprets the results of his field research on assessing Maasai attitudes towards vultures in trying to find solutions towards preventing poisoning of this highly threatened group of birds. His field research was funded by The Peregrine Fund and he acknowledges Dr William Bowerman of the University of Maryland for supporting his studies.

Munir Virani, Kenya

1) What is your project about?

My project looked intensively at how the Maasai people near the Masai Mara perceive vultures.

2) What is the past relationship of Maasai towards vultures and other raptors and has it changed recently?

The Maasai are one the few communities in the world that have a strong attachment towards nature, through their culture, medicinal values and aesthetic importance. These attachments are well demonstrated in their relationship and interactions not only with raptors but all birds. Specific to raptors, species were stratified based on gender with some raptors associated with women for example Hooded Vulture and Marabou Stork. Others are seen as charismatic, brave and strong, for example Lappet-faced Vulture (ormotonyi loormuran- meaning the vulture of the warriors), African White-backed Vuture and the Ruppell’s Vulture were associated with men, especially warriors, for their feathers and naming purpose (In the Maasai community, warriors or people of the same age group are not allowed to refer to each other by name. This was a form of respect and dignity. Therefore, warriors refer to each other by creature for example a lion, a vulture, an ostrich etc depending on which one the warrior has killed for his entitlement or recognition. The Augur Buzzard has a profound cultural significance to the Maasai people. It is important in such cultural ceremonies as Olng’esher, a ceremony to legally transform warriors to junior elders. In this ritual, a white substance (maa. enturoto) is smeared to all the graduates from their neck to their legs, representing the whiteness in the front of an Augur Buzzard, signifying its importance to the Maasai community. The Augur Buzzard is also used to predict the outcomes of various situations. For instance, when warriors are going for a raid, the position of the Augur Buzzard is fundamental. In the event that one spots an Augur Buzzard showing the white belly, the Maasai believed that the raid will be in their favour. However, if the Augur Buzzard has it’s back towards the warring party, the outcome is believed to be a loss. In other occurrences when the Augur Buzzard is in motion, flying the opposite direction, this will mean that the opponents will likely retreat along with their cattle and vice versa.

3) Are vultures important in the religious beliefs of the Maasai?

Not much is reported regarding the Maasai religion in relation to vultures.

4) Vultures often take the remains of animals killed by lions, leopards, cheetahs or hyenas. What is the attitude of the Maasai towards those carnivores?

My study showed that they had mixed attitudes with a greater percentage (above 60%) having poor attitudes towards carnivores. When asked to rank these carnivores from the most problematic to least, most respondents ranked hyena as the most problematic. They often referred to a hyena as a witch that kills more than it can consume. Lions were cherished in most instances and were often referred to as a gentleman who only kills when hungry. I found that the poor attitudes towards the carnivores were attributed to the poor relationship that most respondents had with the wildlife authorities and conservancies which invariably resulted from livestock depredation and lack of benefit accrued from tourism in the area.

5) Do Maasai use poison to kill those carnivores and how does this affect vultures and other raptors like Bateleur or Tawny Eagle?

The Maasai respondents I interviewed have adapted the use of poison as a retaliatory attack to carnivores that kill their livestock. They are well aware of the environmental risks associated with the use of this poison. However, because of their strong attachment to livestock as the sole livelihood source, they have resolved to use poison baits to eliminate carnivores. This has adverse effects to both mammalian and avian scavengers with vultures baring the greatest risk of this situation. More than 100 birds have been reported poisoned at one laced carcass.

6) What are the difficulties for the Maasai people to live with carnivores? Do they suffer from economic losses or even lose their lives to some carnivores like lions?

The biggest challenge is how to stop carnivores coming into contact with livestock. Research has shown that livestock is an easy prey and therefore carnivores will always kill either at night in the manyattas or during the day. Livestock depredation frequency increases during periods of prolonged rain. Initially, the Maasai coexisted with carnivores until the introduction of new policies that advocated benefits (economic) and compensation of property damaged. As a result, people have turned to killing these carnivores because of the government failure to honor and implement the policy requirements. In addition, the issue of ownership of wildlife is a big problem in the country with most rural communities especially the Maasai viewing them belonging to government and have nothing to do with them and therefore should be confined to protected areas or else killed when found prowling settlement areas.

7) What can be done to help Maasai to coexist with carnivores?

One is compensation; two is education and awareness on the importance of these wildlife and lastly benefit sharing which should be on an equitable manner.

8 ) How do you explain to Maasai the importance of vultures and raptors?
I have been approaching this from an awareness angle. Because the community is diversifying, and most of the cultural attachments or values to raptors are declining, the younger generation should be taught the cultural importance of raptors. In addition, educating the Maasai on the environmental and ecological importance of raptors is very important. This has been done through outreach programmes carried out by the Raptor Working Group and The Peregrine Fund amongst other organizations through elementary school programmes and community outreach and we are seeing some encouraging results.

9) What can we learn from Maasai about living and coexisting with carnivores and raptors?

That there is much more than the economic gains from wildlife. The Maasai are known to be the healthiest community in the world. This can be attributed to their healthy environment, which is presumably because of their respect for the environment and therefore less disturbance of ecological processes.

10) How should society and the government help the Maasai to live their lives and coexist with carnivores and raptors?

I think if wildlife is managed in a way that fully embraces the local peoples’ needs and aspirations, it would be easier to address the problems of wildlife declines, but if the trend continues where wildlife is managed by a military-like form of management, then the communities will eventually view wildlife not belonging to them and therefore will not support conservation interventions. The government should fully acknowledge the local people in the management of wildlife and natural resources. This can be done by recognising the Maasai ways of livelihood — for example pastoralism — and compensation programmes should be established to help address the problem of retaliatory attacks to carnivores due to livestock loss.

11) How do you see the future of the Maasai and their coexistence with carnivores and raptors in Kenya?

If the trend continues, the future of wildlife in the country is at risk. I foresee a situation where wildlife will only be found in big fenced ranches like in Laikipia area and raptors will also be found in these areas alone. This will form zoos in the country. There is a worrying trend however in that in my study, I found that the younger, more tech-savvy generation of Maasai is losing their connection with nature. Also I found a strong inverse correlation between educated Maasai and their ability to relate to the wilderness.

12) What was your most amazing experience during your project?
The incredible knowledge that the maasai have on raptors.

→ 1 CommentTags:

Interview with Ann Koeslag about the Black Sparrowhawk of the Cape Peninsula in South Africa

November 20th, 2012 · Interviews

 When you travel to southern Africa to look for raptors it is easy to focus mostly on either the large and spectacular like the Martial Eagle, the endemics like the  Black Harrier or the really rare ones like the Taita Falcon. But that would be a mistake as the more common birds are equally fascinating – and not necessarily easier to find in the case of the Accipiters. We were hoping to see a Black Sparrowhawk and thanks to Ann Koeslog we got amazing views of this fascinating raptor (and also the Rufuos-chested Sparrowhawk). Ann has a research project going on about the  Black Sparrowhawk and it was immediately obvious that she is very passionate about those birds. This is what research and conservation needs today – passionate people who really care about their work the the animals they study. We we were happy to have had the chance to spend a day in the field with Ann and I want to thank here very much for answering this interview questions.

Markus Jais, Germany.

 

 

1) What is the “Black Sparrowhawk of the Cape Peninsula” project about?

Black Sparrowhawks come in two different forms (morphs). A white chested form/morph and a black chested/morph.

Black Sparrowhawks come in two different forms (morphs). A white chested form/morph and a black chested/morph.


 

 

Until 2000 the Black Sparrowhawks were being studied in a piecemeal manner, but then a project was started on the Cape Peninsula to look at them more comprehensively. Subsequently, a student has started a Masters’ project at the University of KwaZulu-Natal in 2011 to look at these birds in that province. We are quite excited about what will be found, because the two areas (the Cape Peninsula and KwaZulu-Natal) have quite different habitats and different climate conditions.

The climate on the Cape Peninsula, which is the little crooked finger of land that sticks out into the Atlantic Ocean on the south-western tip of Africa, is very dry and windy in summer and cold and wet in winter. Because of this, the indigenous flora consists of low growing plants with only a few species of trees, which tend to be restricted to the occasional ravine, where there is a constant source of moisture.

Map of the  Cape Peninsula and it's place in South Africa

Map of the Cape Peninsula and it’s place in South Africa

Like most of nature’s opportunists Black Sparrowhawks probably arrived once the plantations of pine and eucalyptus, which were planted on the Peninsula’s mountainsides during the mid-1900s, were tall enough to support their nests. They prefer the pines, but will use eucalyptus, poplar and black wattle (Acacia mearnsii), all of which are alien to South Africa, in preference to the indigenous trees.

They do nest in indigenous trees in areas of South Africa where there are large indigenous forests, but I get the impression that, mostly, they prefer pine trees.

Black Sparrowhawks are extremely adaptable and will live in practically any clump of trees, as long as the trees have suitable branches for their nests, and they deem the humans in the vicinity not to pose a threat. This is fortunate for them in a country where water is in short supply, and where natural forests are not common.

To give you some idea of the variability of nests, our highest is at 56 metres and the lowest at 3½ metres. The latter could be reached using the small ladder from my home when we went to ring the chicks. That tree was unfortunately cut down a little later by the owner of the property.

 

Mark climbing to a nest about 56 m from the ground. He is in the circle at the bottom and had already been climbing for 20 minutes. The nest is in the circle at the top.

Mark climbing to a nest about 56 m from the ground. He is in the circle at the bottom and had already been climbing for 20 minutes. The nest is in the circle at the top.

 

The lowest tree that we have had a nest in.

The lowest tree that we have had a nest in.

One of the first things we noticed about the Black Sparrowhawks on the Peninsula was the prevalence of so called “black morphs” in the population (see picture above). In the rest of Africa the birds are white from under their chins right down to their underpants, termed “white morphs” (See picture above). But on the Peninsula about 66% of the birds are black morphs. They can be totally black or have white throats, sometimes with white flecks on their chests and bellies. On looking into the matter it seems that the black morphs are fairly common up the east coast of South Africa, but very rare elsewhere.

2) What is the most common hunting method of Black Sparrowhawks?

They do not seem to hunt in the forests, but out in the fields, vineyards and urban gardens where they find their preferred prey. The female can take birds as big as Francolin and Guinea Fowl, but their commonest prey is pigeons and doves and a soupçon of smaller birds like starlings.

When hunting they tend to sit quietly in a tree waiting for birds to gather, and then to swoop down on them. Another strategy is to fly quite low over the ground in the hope of flushing a bird. They also sometimes attempt to catch pigeons or doves on the wing, but pigeons and doves are amazing long distance flyers and can generally out-fly and out-distance the Black Sparrowhawks; so why they attempt this form of hunting is a mystery. The Black Sparrowhawk is, we believe, at its best when swooping down on prey that is taking off from the ground or from a low perch.

3) What is known about the population trend and conservation status of the Black Sparrowhawk in South Africa?

The Black Sparrowhawk is considered not to be an endangered species, but, because their prey base includes chickens and pigeons, this regularly brings them into conflict with humans. So they are regularly persecuted, both in rural areas and towns. Although all raptors are protected in South Africa, policing their persecution is not taken seriously, probably because of a lack of resources.

Another problem facing these birds at the moment stems from their predilection to nesting in alien trees (especially pines), which are systematically being removed from conservation areas such as the Table Mountain National Park.

South Africa is at present in the throes of atlasing all the bird populations of the country. What it has shown for the Black Sparrowhawk is that their population appears to have grown, and that there has been a south-westward movement which is intriguing. Territories have been lost in the north-east of the country (e.g. Mpumalanga) but their range has expanded in the south-west (e.g. the South Western Cape). Between the first atlasing project (SABAP1 1987) and this one (SABAP 2), there is the same number of territories, but 50% of them have been lost in the north-east but gained in the south-west.

4) Do they also live in cities?

I am slowly coming to the conclusion that, although they do live in the wild, they are more numerous when living near human settlements. Their prey base of mostly pigeons and doves is most numerous near human settlements, which means that being close to people, the Black Sparrowhawks rarely have to search far for a meal. We have two breeding pairs which live right on the edge of central business district of Cape Town. The one nest is in a park, about 50 m from some very busy tennis courts and where every man and his dog wander around.

5) What are the difficulties when studying Black Sparrowhawks?

On the Cape Peninsula finding nests and monitoring them is reasonably easy. Luckily the birds are noisy during the breeding period, so in many instances we find them by their calls. About half the territories are found in the Table Mountain National Park and the rest in municipal greenbelts, golf courses, small holdings and private estates. Some of the territories occur in high crime areas and then personal safety (for the monitors) becomes a real issue. Luckily we have an enthusiastic group of volunteers who are always willing to band together for safety.

The other problem is that the birds are tree-nesting raptors. To place rings on chicks we therefore require the services of an experienced tree-climber who also knows how to handle the chicks. Mark Cowen is such a person, and has been one of the king-pins of this project. He is very inventive, safety conscious, and gentle when handling chicks.

6) What is the relationship with the Egyptian Goose and Pied Crows?

The Egyptian Goose population has increased enormously, both in numbers and in range. It came as quite a surprise to us that these traditionally ground-nesting water birds could wreak such havoc on a tree-nesting raptor.

Egyptian Geese are remarkably good parents and have long ago worked out the advantages of taking their eggs out of the reach of ground predators. Normally a flattened bed of reeds or grass lined with down from their breasts would be where they generally lay their eggs, but now they constantly try to evict raptors from their nests, to use them for their own eggs. A female Black Sparrowhawk has a mass of ~1000 g and a male of ~560 g. A female Egyptian Goose has a mass of ~1900 g and a male of ~2300 g. We have had a camera up at a nest recently and the fights between the hawks and geese have been vicious. The geese will fly full-tilt into the nesting raptor, to knock it right off the nest. The Sparrowhawk will then do the same to the goose, often with her talons out-stretched, which may or may not be successful. The camera has revealed that the geese will return several times a day to renew the attack, so that it is a wonder that the female Sparrowhawk can properly incubate her eggs, or that the eggs are not broken during the violence of the attacks. However, this camera was at only one nest where the female Sparrowhawk was eventually successful at hatching her eggs. We suspect that success of this sort is not very common.

A Black Sparrowhawk nest with goose in it.

A Black Sparrowhawk nest with goose in it.

The other problem that all the birds face is the burgeoning Pied Crow population. In some areas the Black Sparrowhawks can have 40 – 60 of these birds constantly harrying them to steal eggs, chicks or incoming food parcels.

7) What is the breeding success of the pairs in your study area and the main influence of breeding success?

Over 10 years we averaged 1.5 chicks fledged per active nest per year. The Black Sparrowhawks in our area never have more than three chicks in a nest. Nests that are invaded by Egyptian Geese average 0.8 chicks per nest. The Black Sparrowhawks have developed various strategies to counteract the pirating of their nest by the geese. The most common strategy is to build alternate nests that they can to move to if they lose the one they are attempting to breed in.

 

Black Sparrowhawk chick in a nest.

Black Sparrowhawk chick in a nest.

 

8) Is there competition with other raptors for nesting habitat?

We have found African Goshawks, Yellow-billed Kites, Buzzards (Buteo spp.), and Black Sparrowhawks all nesting in the one small stand of trees. No nest was further than 100 m from the other. This posed the problem for the adults having to remain constantly close to the nest during the nestling stage, to prevent predation of their off-spring.

9) Are Black Sparrowhawks sometimes eaten by other raptors, e.g. large owls or eagles?

We have never seen a case of an adult Black Sparrowhawk being predated by another raptor. On the other hand they are quite capable of taking out smaller raptors. Some of the prey remains we have found under the Black Sparrowhawk nests have been: Black-shouldered Kites, Rufous-chested Sparrowhawks, African Goshawk and Wood Owl.

10) What is known about the movements (migration, dispersal) of the species?

Our Black Sparrowhawks don’t migrate and they can sometimes be found in their nesting territories outside the breeding season. They are quite capable of hunting ~6 km from the nest even when they have chicks to feed. Finding them outside the breeding season is a problem because they are then generally silent, and usually not in the immediate vicinity of their nests. That they do not migrate is evidenced, however, by them being spotted hunting in suburban gardens, in much the same areas where they hunt during the nesting period.

They do however disperse to new territories, especially the juveniles who are seeking their own places to nest. The furthest we know of a ringed bird going is 64 km, but we would not be surprised to find them even further away.

11) What was your most amazing experience with Black Sparrowhawks?

In 2009 we were called out to a small holding one night because the resident nesting female had been rescued from a large concrete water storage container and seemed to be in poor condition. On examination we couldn’t find anything the matter with her except that she was cold and wet. After drying her out, she was stored in a cardboard box overnight. Mark, our climber was on hand, and he climbed to the nest and removed the two, two-and-a-half week old chicks for safety. They too were stored in a separate container to wait for morning.

I must mention that both parents are remarkably calm birds with a nest about 40 metres from the chicken run on this small holding. The owners of the property love having them there so do not interfere with them in any way. As a result the birds are not too particularly worried by us monitoring them.

The next morning we restored the chicks to the nest and released the female from her box. Both chicks, which we ringed that morning, subsequently fledged.

 

Female chick, ringed purple over purple on left leg.

Female chick, ringed purple over purple on left leg.

This year one of those chicks turned up at a territory (AT) 15 km from where she had fledged. She had turned into a black morph and was paired with a mature white morph male who, although not colour ringed, we recognise from his behaviour. Later on that morning we found her at another territory (CHF) about 800 m from the AT territory, also with an unringed white morph male in attendance. This male was very young judging by his eye colour. Just to make sure that we were not hallucinating we stationed one team at the AT territory and another at the CHF territory and within an hour established that she was moving between the two nests and had a male in residence at both.

 

Purple over purple on left leg chick as an adult.

Purple over purple on left leg chick as an adult.

 

Mature white morph male at AT nest.

Mature white morph male at AT nest.


She eventually decided in favour of the younger male at the CHF territory and laid her eggs and settled in to incubate. At this point it was decided to install a camera at that nest. This particular nest is an anomaly, because instead of being on the main trunk of the tree it is a long way out on a limb. This makes it a particularly difficult climb for Mark because he cannot put any of his weight on the branch for fear of destroying the integrity of the nest. Using a series of higher branches he can get right next to the nest without disturbing it.

When he got up there, the female flared slightly but refused to leave her eggs. This is the first time this has ever happened in our experience. So for 50 minutes Mark worked around the nest and even spent some time sitting about 60 cm from the bird, who stayed put. At one point he moved his hand near her and all she did was show him her talons and as soon as he removed his hand she relaxed again.

 

Mark sitting next to the female on the CHF nest.

Mark sitting next to the female on the CHF nest.

This is the bird that we have photographs of resisting constant takeover bids by Egyptian Geese during the course of one day, so she is not placid about protecting her nest.

A few days ago we went back to the nest to ring the chicks. I think the whole team were worried by the sort of reception the climber would encounter if the bird refused to leave her chicks. Mark got to the nest and was once again greeted by a bird which steadfastly refused to budge. She flared in protection of her chicks and struck Mark once in the face as a warning, but, as usual he took things very slowly and carefully, and after a few minutes managed to remove a chick from the nest. We decided to send one chick down at a time so as not to leave her with an empty nest. This worked well and both chicks were quickly ringed.

 

Female on the CHF nest with her chicks at the time of ringing

Female on the CHF nest with her chicks at the time of ringing

We have also taken note of the fact that she is still visiting the AT territory, and suspect that she is keeping any other females from using it. The story continues ………

We are constantly amazed at how each bird has its own personality. When we are ringing chicks some parent birds just go off and sit quietly in a tree nearby and keep an eye on what we are doing. Others get so furious that Mark occasionally is attacked by them. I don’t think that anyone can actively follow a creature’s life, recording its parents’ and grandparents’ lives without becoming totally besotted with them. This year we are monitoring ~45 nests so life is full of interest.

→ 7 CommentsTags:

Interview with Garth Batchelor about the African Crowned Eagle in South Africa

April 21st, 2012 · Interviews

Garth Batchelor

Garth Batchelor

 In January 2012 I was on a raptor and wildlife watching trip in South Africa with Bill Clark, Sergio  Seipke and raptor enthusiasts from The Netherlands, United States and Germany. We spend more than 3 weeks visiting many great places and meeting many great people like André Botha, Peter Steyn, Rob Martin, Jessie Walton, Malcom Wilson and Ann Koeslag. We had many highlights incl. 5 species of cats, Martial Eagles, Taita Falcons, Black Harriers and much more. My personal highlight was the African Crowned Eagle. Bill managed to organize for us to meet Garth Batchelor, one of South Africa’s leading experts on the Crowned Eagle. When we met Garth on our last day in Kruger Nationalpark we already had two short and not very good glimpses of Crowned Eagles but we were hoping to get a much better view. The next day Garth took us too a beautiful place and showed us not only an almost fully fledged juvenile (see picture below) but the adult pair also appeared flying above us and we had a fantastic morning there. Garth is not only a really nice guy but he answered all my questions – and I asked a lot – with lots of fantastic information about this beautiful and powerful eagle. I am very happy that Garth agreed to do this interview and share his knowledge about the ecology and conservation of the Crowned Eagle in South Africa. The situation in  South Africa gives reason for hope and with dedicated people like Garth working for the conservation of African Crowned Eagles I am optimistic for the future of Africa’s most spectacular and fascinating bird of prey.

Markus Jais, Germany

 

1) What is the current status of the African Crowned Eagle in South Africa?

The African Crowned Eagle is currently classified as near threatened in South Africa. This means that its population should be monitored.

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

It is my perception that the population of this eagle have probably remained fairly constant over the past decade or more. This is due to the fact that they live in remote usually fairly densely forested, mountainous habitats. These areas are often largely inaccessible. They are also secretive birds being difficult to see during most of the year. The often sit quietly on favorite perches often in deep shade for hours waiting for prey to pass by.

Female African Crowned Eagle

Female African Crowned Eagle, © Garth Batchelor

3) How does habitat destruction affect the African Crowned Eagles?

Fortunately the patches of temperate forest along the mountain ranges in South Africa are all protected. These forest patches are the favoured habitat for these large eagles and provide habitat for small antelope such as Blue and Grey Duiker as well as Bushbuck and Vervet and Samango Monkeys. In the Eastern Cape they live in thick succulent vegetation which is very thorny with many euphorbias.

4) Does illegal and maybe legal bird trade threaten the African Crowned Eagle in South Africa?

There is little recorded trade in African Crowned Eagles. Only a limited number of these eagles are kept by falconers under license. The collection of wild birds is strictly controlled by the conservation agencies.

African Crowned Eagle with chick.

African Crowned Eagle with chick. Note the impala leg! Quite a large meal for such a small bird. This impala was probably a year old and would have weighed about 20Kg or more. © Garth Batchelor

5) Are many birds shot or poisoned?

This is difficult to answer. It is probable that immature birds are shot or trapped if they hunt in urban areas or rural villages. An incident was reported to a forester by a labourer of a big bird catching and killing his small pigs. Fortunately the culprit eagle was not killed even though the nest with a chick in was less than 200 meters from the homestead. There are other reports of “urban“ eagles taking pet dogs and cats. They are definitely opportunists and will take live prey what is available that they can overpower.

6) What other threats affect the African Crowned Eagle?

Being a predator they will always come in conflict with small stock farmers. Goats are easy prey and in the Eastern cape where goats and sheep are farmed extensively farmers will shoot these eagles. In the area around Nelspruit there are a number of conservancies where antelope are farmed for hunting. The African Crowned Eagles will take the young of many antelope species including Bushbuck , Grey Rhebok and Impala. This can be difficult for the farmer to tolerate but generally they are sympathetic to the eagles.

7) What is known about the diet and food requirements of the African Crowned Eagle in South Africa?

As mentioned African Crowned Eagles are opportunists. They will take prey that is available in their territory that they can overpower. In a study on the prey items around Nelspruit in antelope formed over 70% of the diet with Vervet Monkeys also featuring highly.Other prey items included Genet Cats, mongoose, and a small porcupine. Porcupines are normally nocturnal so this is a mystery. In other areas of South Africa Rock and Tree Hyrax are selected. Birds such as Guinea Fowl and even Hadedah Ibis have been recorded as prey. The bones of prey once they have been pecked clean of muscle and sinews are dropped over the edge of the nests and these are recycled by Bush Pig and also by Porcupines.

Juvenile African Crowned Eagle

Juvenile African Crowned Eagle, © Markus Jais

8 ) What habitat do they need? Can they live in habitat altered by humans?

African Crowned Eagles require forest with large trees. The nest tree is usually one of the tallest in the forest and can be up to 30m high. They also seem to select areas which are mountainous. This could be because they perform intense aerial displays before mating and use updrafts often associated with cliff edges to rise up quickly from where they can perform their displays. They appear to have adapted well to areas where extensive plantation so f exotic trees have been planted for timber. These trees may provide nest sites in the larger trees that have become wild in some of the drainage lines reached 30 or more metres i9n height. Pine plantations also support healthy populations of Grey Duiker which are a preferred prey item. Sub Tropical fruits are grown around Nelspruit which can attract Vervet Monkeys. As African Crowned Eagles also readily hunt Vervet Monkeys they are actually welcomed by fruit growers.

9) How large are the typical home ranges of an established pair?

Around the Nelspruit out of a sample of 40 nests, we have calculated the average territory to be about 30 square kilometers. This is small for an eagle of their size compared to a Martial eagle which has a territory size of about 250 square kilometers.

Watching Crowned Eagles

Watching Crowned Eagles in South Africa. Garth Batchelor (center), Exon Twala (right) and the interviewer Markus Jais (left), © Markus Jais

10) What is known about the dispersal and movement of juvenile and immature birds?

This is one of the big questions that we would love to answer. The fate of the juvenile birds after leaving their home territories is not known.

11) How often do African Crowned Eagles breed? How long does it take for them to raise a chick?

African Crowned Eagles have one of the longest breeding cycles of any eagle. In this respect they are similar to the Harpy Eagles of the Amazon. The nest building starts in the middle of winter, in July or early August. Egg laying can be at the end of August but is usually in September and sometimes even October. Incubation is about 51 days while the chick will take up to 110 days to fledge. I have recorded the fledged chick still being in the vicinity of the nest 9 months after fledging and still being tolerated by the adults. The long period required for the chick to become independent is presumably the reason why these eagles breed every second year. Pairs have been recorded to breed annually but we suspect that when this occurs it is because something has happened to the chick.

12) What is the average breeding success? Are there any cases with two chicks successfully fledging?

We have recorded that remote secure territories continually raise a chick every second year whereas nests close to urbanization more frequently attempt to breed annually. Without actually marking the chicks it is not possible to say definitively what is a happening to the fledged chicks but suspect there is a higher mortality of chicks closer to human settlements. We have not recorded two chicks surviving even though two eggs are usually laid .

African Crowned Eagle: Prey remains

African Crowned Eagle: Prey remains, © Markus Jais

13) What is known about the relationship with other eagles like Martial Eagles or other raptor species? How are they ecologically separated?

 

There has been no research on this subject but suspect that African Crowned Eagles are better adapted to a forest habitat. They are like giant Goshawks with round wings and long tail making them very maneuverable in thickets. They spend most of the time sitting unobtrusively waiting for prey. Martial Eagles are master gliders spending most of the day in the air at high altitudes. They are in my view more suited to open savanna where as the Crowned Eagle is a forest specialist. This is born out by the large territories of the Martial Eagle.

14) Do Crowned Eagle benefit from private Game Farms?

They can benefit from game farms unless the owner of the farm considers them a threat to his livelihood. Most game farmers however welcome the eagles on their farms .

15) What gaps in our knowledge of this large eagle do still exists?

The biggest gap in our knowledge is knowing what happens to the immature birds after fledging. Together with this is whether some pairs or populations actually do breed annually as suggested by some researchers.

16) Where should research focus during the next years?

In trying to provide answers for the above two questions. The fitting of satellite transmitters could provide answers to these questions.

The number of nests being monitored should be expanded with ideally working groups starting up throughout their range.

17) What can and must be done to secure the survival of the African Crowned Eagle in South Africa?

Instill a greater awareness and appreciation of these birds amongst landowners who have them nesting or using their properties

18) What is the Crowned Eagle working group and what are it’s tasks and projects?

The Crowned Eagle Working Group (CEWG) consists of a few members of the local Lowveld Bird Club which is a branch of Birdlife South Africa. All landowners with African Crowned Eagle Nests on their properties are automatically members. A core group of members attempt to monitor the breeding success of each nest annually. When possible, prey remains below the nests are recorded and identified. It was realized that after starting to locate nests in the vicinity of Nelspruit that there is strong population of these eagles around the town. We are now monitoring the breeding success of 40 pairs within a radius of 70km from Nelspruit. The CEWG is working closely with all the forestry companies along the Drakensberg escarpment as well as with game farm owners advising them on the conservation of the CE.

The CEWG supported a student from the UK in 2009 to undertake a master degree on the ecology of the Crowned Eagles and would support further research initiatives.

19) How do you see the future of the African Crowned Eagle in South Africa and beyond?

With the growing awareness on these eagles by landowners and the positive support the CEWG has received over the past few years I am confident that the African Crowned Eagles around Nelspruit are in good hands. From communication we are receiving from other Provinces it would appear that this eagle is managing to maintain its populations and is even surviving in developed urban environments.

20) What was your most amazing experience with the African Crowned Eagle?

Standing on the edge of a massive cliff on the Drakensberg Escarpment at Kaapschehoop 30 km west of Nelspruit in early July 2009 I witnessed one of the most thrilling aerial displays that one could wish for. From down in the valley below a pair of African Crowned Eagles soared up in spirals until they were almost out of sight in the clouds. They then started to display calling loudly all the time. They approached closer and closer towards my wife and I till they were only meters away rolling, looping and diving through the sky.

The two following photos were taken by myself on this occasion.

African Crowned Eagle displaying

African Crowned Eagle displaying, © Garth Batchelor

 

African Crowned Eagle displaying

African Crowned Eagle displaying, © Garth Batchelor

 

 

→ 8 CommentsTags:

Interview with Sonja Krueger about the Bearded Vulture

March 17th, 2012 · Interviews

Sonja Krueger with Bearded Vulture

Sonja Krueger with Bearded Vulture

I have had the privilege of working with Sonja Krüger and observe her
dedication and drive to conserve the Bearded Vulture in southern Africa
since 2004.  Working as an Ecologist with KZN Wildlife and as the
coordinator of the Bearded Vulture Task Force of the EWT’s Birds of Prey
Programme, Sonja has been able to successfully implement and adapt our
approaches to the conservation of the species in our region across its
entire range and involving stakeholders from a range of international,
national as well as provincial institutions and NGO’s while involving
land-owners and other communities in this initiative. Sonja’s dedication is
expressed in so many ways, but conducting monitoring in the
Maloti-Drakensberg in mid-winter, often on foot, and spending hours in a
variety of cramped hides waiting to capture birds for tracking purposes are
two examples thereof. The scope of work and advances made in conservation
action focused on Bearded Vultures in the region are further testament to
Sonja’s hard work in ensuring that these birds will remain the flagship
species associated with the Maloti-Drakensberg and resulted in Sonja being
awarded the Vulture Conservationist of the Year Award in 2007. She is
cuurently completing her PhD focused on this species with the university of
Cape Town.

André Botha, South Africa

 

1) What is known about the current status of the Bearded Vulture in Africa?

The isolated population in southern Africa has about 100 breeding pairs in the Maluti-Drakensberg mountains with a total population of between 300 and 350 individuals. Ethiopia is still believed to be the stronghold of the species in Africa although no recent estimates exist. Only a few pairs are left in Kenya, Uganda and Tanzania.

 

2) Has the population changed during the last decades?

Detailed research was done on the species in southern Africa in the 1980s. At the time the population was estimated at 200 breeding pairs. Many nest sites in peripheral areas have been abandoned and the breeding range has reduced in size. It is assumed that this is as a result of increased human disturbance at these sites, either infrastructural developments or increased population density and intensity of farming activities.

Adult Bearded Vulture

Adult Bearded Vulture, © Stephanie Walters

3) What is known about the genetic difference between the birds in southern and eastern Africa and those outside of Africa?

The population south of the Tropic of Cancer (Gypaetus barbatus meridionalis) is thought to be genetically distinct from that north of the Tropic of Cancer in Africa, Europe and Asia (G. barbatus barbatus). Godoy et al. (2004) on the other hand suggest that the global Bearded Vulture population could be treated as a single population since there is no significant difference in life history traits, morphology, habitat or behaviour. However, their assessment was based on only three samples from sub-Saharan Africa. Samples from southern Africa are currently being analysed to increase the sample size to substantiate the finding of Godoy et al. (2004). The results of these findings have implications on the future management of the population

 

4) What is the preferred habitat of the species?

The birds prefer mountainous terrainand escarpments where they nest in potholes on cliff faces at altitudes above 1800m and on average at 2800m. They forage over lowland areas, over open terrain where they can spot carcasses at a distance.

 

5) Is there competition with other raptors about food and nesting places?

Since the Bearded Vulture’s diet consists almost exclusively of bone (which is swallowed), there is no competition at feeding stations. They are famous for carrying bones to heights from which they drop them to break them into smaller pieces that can be swallowed with ease. Adults do require meat in the breeding season to feed the chicks. Corvids have been seen harassing Bearded Vultures at established feeding stations where small bone fragments and pieces of meat are placed out for the birds. These morsels appeal to most of the large raptors and the Beardeds tends to steer clear of a lot of scavenging activity.

Bearded Vultures are often found nesting close to Cape Vultures. The habitat preference and choice of nesting sites of Verreaux Eagles is similar to that of the Bearded Vulture and altercations between these two species occur frequently.

 

Adult Bearded Vulture flying

Adult Bearded Vulture flying, © Sonja Krueger

 

6) What is the main food for the Bearded Vulture? Is the Bearded Vulture dependent on Livestock?

Ideally the birds feed on the carcasses of small to medium sized mammals, although bones of larger animals can be broken into smaller pieces. A large part of the species’ range is open grassland where livestock (sheep, goats, cattle) are abundant in summer. In winter, the birds are more reliant on supplementary feeding at feeding stations. In protected areas they feed on wildlife carcasses/afterbirths, particularly when these are plentiful in summer during the lambing/calving season.

 

7) How important is the presence of large carnivores like lions or leopards as a provider of carrion for the Bearded Vulture?

Large carnivores are scarce throughout the range of the species, therefore these are not important providers of carrion. Bearded Vultures inhabit harsh environments where many animals succumb to the affects of adverse weather and accidental deaths in steep, hostile and inaccessible terrain. Land use change over the past few decades has resulted in large scale transformation of their habitat making supplementary feeding a necessary conservation management action.

 

8 ) Are Bearded Vultures affected by poisoning?

Poisoning is one of the primary causes of mortality. To date three out of 14 birds fitted with satellite tracking devices have been killed by poison. Bearded Vultures are often accidentally poisoned when feeding on poisoned bait meant for jackal. Since all vulture species are particularly sought after in the traditional medicine trade, the Bearded Vulture is not spared from deliberate poisoning, although they may be more difficult to target. Many herdsman still believe that the birds prey on lambs and deliberately shoot or poison them.

 

9) In Europe, Bearded Vultures are threatened by lead poisoning (by ingesting lead ammunition). How is the situation in Africa?

Conservation agencies in southern Africa are well aware of the lead threat and are making every effort to inform the public and hunting fraternity of this threat as well as changing the type of ammunition used, the method of culling and disposal of carcasses. Wild caught birds that have been tested for lead levels have not shown unusually high levels of lead. Limited hunting takes places within the range of the species.

Bearded Vulture nest

Bearded Vulture nest, © Sonja Krueger

10) What other threats for the species do exist?

Collisions with energy structures such as powerlines and wind farms remain the next biggest threat to the species. Additional threats include habitat loss and food shortage as a result of land use change and improved animal husbandry. Human persecution and nest disturbance, are minor threats in Africa but the impacts of mountain climbing on nesting success still needs to be investigated. New threats to the species include their potential vulnerability to climate change and requires further investigation.

 

11) What is known about breeding success and the annual survival of Bearded Vultures?

The breeding success of the species within their core range is high and similar to that found in the 1980s (about 85%). However breeding success at peripheral sites is much lower with many of these sites having been abandoned over the past few decades.

 

There is limited recent information on the survival rate of the species. A marking programme has been initiated to provide more information on this and research is being done to determine the number of individuals that survive to the next age class. The average annual adult survival has been estimated at 95% and other age classes have a average survival rate of 11% . Longeivity is estimated at about 20 years in the wild.

 

12) What gaps in our knowledge about the Bearded Vulture do exist and where should research focus in the next years?

Research should focus on i) which environmental variables account for the abandonment of breeding territories, ii) whether there are age specific differences in the spatial and temporal use of home range that places the birds at risk, iii) whether the population has enough genetic variation and is genetically similar to other populations in sub-Saharan Africa, iv) what the primary factors affecting survival and breeding success of the population are, and v) what the future growth rate of the population is likely to be and vi) what the conservation interventions are that can effectively influence this trend.

 

13) What needs to be done to secure the future of the Bearded Vulture in Africa?

There is an urgent need to address the threats to the species in particular the threat of poisoning and ever increasing threat of land use changes and associated infrastructural developments (e.g. powerlines). Education and Awareness of the great public on the importance of the species and its role in the environmental is essential. Captive breeding for supplementation of the wild population must be considered but will only be implemented once the threats to the species have been adequately addressed.

 

14) Are there any conservation projects or research projects for the Bearded Vulture?

A Biodiversity management Plan is in preparation for the species which details the conservation objectives for the species and lists the operational goals required to address these. The gaps in our knowledge are currently being addressed through a research programme which aims to address the points listed in 12 above.

Immature Bearded Vulture

Immature Bearded Vulture, © Sonja Krueger

15) How can people help to protect the Bearded Vulture?

People can dispel the myths that these birds are predators and catch lambs, report sightings of marked birds, report the location of any known nest sites and encourage the use of alternate methods of predator control and alternate options f energy provision.

 

16) What was your most amazing experience with Bearded Vultures?

Over the past few years, I have had many amazing experiences with the birds. After a long days hike to a nest in the mountains, it is always rewarding to see the birds at the nest- even if you can’t see inside. Watching birds landing and feeding at close proximity is always special. I’ve had the privileged of handling a number of these birds and am always captivated by how large and majestic they are. But the most amazing experience must be sitting camouflaged in the grassland listening to the wind whistling in their wings as the circle a few meters above your head.

 

 

 

→ 1 CommentTags:

Interview with Craig Whittington-Jones about the African Grass Owl

February 16th, 2012 · Interviews

Craig Whittington-Jones

Craig Whittington-Jones, © R. Deysel

Craig was born and raised Cape Town. He was an undergrad and PhD student (Zoology) at Rhodes University in Grahamstown.
Since 2000 he has been employed as ornithologist (and herpetologist of-and-on) by Gauteng Nature Conservation.

Although not primarily a raptor biologist, he has however worked quite extensively with the EWT’s Bird of Prey Programme/
Project (and before that with the EWT’s Raptor Conservation Group and Vulture Study Group) on various initiatives including the African Grass-Owl Force which he co-chairs with Geoff Lockwood.

Craig is also involved with monitoring Cape Vulture breeding colonies and assisting with an assessment of the status of Verreauxs’ Eagles along the Magaliesberg ridge in RSA.

He coordinates province-wide large terrestrial bird counts in Gauteng (as part of the Animal Demography Unit’s Coordinated Avifaunal Roadcount Project (CAR) which include Secretarybirds as one of the key target species) and he will will also be involved with the grassland component of BirdLife South Africa’s Secretarybird tracking project.

His current preoccupations are the various initiatives of the Grass-Owl Task Force, a reassessment of the red list status of the African Grass-Owl, and the South African Bird Atlas Project (SABAP2).


1) How large is the range of the African Grass Owl?

In South Africa the range of the species is less than 14 000 km2, where it is largely confined to the eastern half of the country and is most commonly reported for the provinces of KwaZulu-Natal, Mpumalanga and Gauteng. Elsewhere in southern Africa there are surprisingly few records for Mozambique and Botswana, but it was widespread in Zimbabwe (though reportedly not commonly encountered these days) and it has been recently reported for the Caprivi though other older Namibian records have proven erroneous. I have little knowledge of the species further north in Africa, though I am aware of old records including museum specimens from Zambia, Malawi, Rwanda and the Democratic Republic of Congo and the literature indicates that the range extends east through Tanzania, Uganda and Kenya with at least one record for Ethiopia and a few from as far west as Cameroon.

African Grass Owl chicks

African Grass Owl chicks, © R. van der Westhuizen

2) What are the closest relatives and how do they differ in behaviour and ecology?
The Eastern Grass-Owl Tyto longimembris, which occurs from India through China and south-east Asia to Australia, is considered by some authors to be conspecific with the African Grass-Owl, but in South Africa the Grass-Owl is most closely related to the Barn Owl Tyto alba. While there is some overlap in the habitat and prey (both feed primarily on rodents) of the two species, the Barn Owl is a high adaptable generalist able to exploit a diversity of natural and man-made environments including areas of intensive agriculture and urban sprawl provided that adequate prey and shelter are available. In sharp contrast, although populations of Grass-Owls may occasionally persist on the peri-urban fringe in areas where wetland roost habitat is protected from excessive burning, trampling and general disturbance, this species is far more dependant on natural landscapes than the Barn Owl. Both species hunt mainly at night using a low quartering flight and perches (the latter more so in the case of the Barn Owl probably because of relative availability of perches in their chosen habitats), but whereas Barn Owls may roost in a diversity of natural hollows, caves and crevices as well as in man-made structures during the day, Grass-Owls appear to roost almost exclusively in hollows in rank grass. While few who have visited an active Barn Owl territory at night can fail to have heard its characteristic drawn-out screech, the Grass-Owl appears to be considerably less vocal.

3) What is known about the current population of the African Grass Owl and how has the population changed over the last decades?
This is an area of research that urgently requires considerably more attention. Current population estimates for South Africa are at best little more than an educated guess and there appears to be even less information for the rest of their range. Good population data are only available from a handful of sites in South Africa and all surveys except for those in the Settlers area in Limpopo Province (surveyed in the late1970s) and Suikerbosrand Nature Reserve in Gauteng (surveyed annually since 2009) covered only relatively small areas.

Data from Suikerbosrand NR suggests that population fluctuations between years may be quite dramatic, something that should be expected in an ecosystem where rainfall, fire and grazing pressure can significantly affect cover and prey availability in the course of a single season. Of more immediate concern is the bird atlas data for South Africa (SABAP1 and SABAP2) which indicates an alarming decline in the Grass-Owl’s area of occupancy and reporting rates over the past 30 years or so over much of the species’ range. Data collected from various unpublished sources for the period between the two atlas projects gives some hope that the situation is not as dire as it might appear at first glance, but there can be little doubt that widespread land transformation and inappropriate management of large areas of remaining otherwise potentially suitable habitat have resulted in a population decline over the last few decades.

African Grass Owl habitat in SE Gauteng

African Grass Owl habitat in SE Gauteng, © Graig Whittington-Jones

4) What is the main habitat of the African Grass Owl?
In the grassland biome the species typically roosts and breeds in tall rank grass or sedges in or adjacent to seasonal wetlands and along drainage lines foraging more widely over surrounding grasslands and agricultural fields. Elsewhere the species has been reported to utilize a diversity of vegetation types including open savanna with long grass, thorny bushveld, scrub, fynbos, renosterveld, bracken and even karroid vegetation though in most cases the chosen habitat was associated with a wetland of some sort.

5) What is the owl’s main food?
Rodents are the primary prey throughout their range, but shrews, bats, birds, frogs and invertebrates may feature in their diet to a lesser extent. I have yet to find frog or bat remains, but opening pellets can be surprisingly addictive so there is still a chance.

6) Does the African Grass Owl compete with other owl and raptors species for food and breeding places?
In the grassland biome, the breeding and foraging habitat of the more common Marsh Owl Asio capensis overlaps most closely with that of the Grass-Owl. Despite reports of aggressive interactions between the two species, they generally appear quite tolerant of each other and may nest/roost in relatively close proximity in the same wetland. While both species prey primarily on rodents, Marsh Owl pellets frequently include a much greater invertebrate component and when combined with their typically more diurnal activity pattern, foraging competition between the two species may be reduced to some extent. This is nevertheless and interesting topic for further research and Geoff Lockwood has begun looking into it.

The foraging habitat and prey of the African Marsh-Harrier Circus ranivorus also overlap with that of the Grass-Owl, and while the Marsh-Harrier has become rare in Gauteng, there is potential for competition elsewhere within their shared range.

African Grass Owl roost

African Grass Owl roost, © Craig Whittington-Jones

7) What are the natural enemies of the African Grass Owl?
As a ground-nesting species there is no shortage of potential predators during the breeding season. While nest failure due to predation appears relatively common (possibly as a result of a human observer creating a convenient path or scent trail to the nest site), the only recorded incidents of predation that I have encountered are by an African Marsh-Harrier on a juvenile/immature Grass-Owl at a roost and the killing of a female and her chicks by what appears to have been a Serval.

8 ) How does habitat destruction and a more intensive agriculture affect the African Grass Owl?
This is a very broad topic especially as the main drivers of habitat destruction vary across the range of the species. My experience lies mostly in the peri-urban environment where it appears that Grass-Owl populations may persist, at least over the short term, within a transformed landscape provided that adequate foraging and nesting/roost habitat remains available. Unfortunately we don’t yet have a good idea of the spatial requirements of the species and even where new urban developments attempt to plan for the inclusion of Grass-Owl habitat in an open space network, the area set aside often proves too small or is impossible to manage appropriately (e.g. fire is an essential tool for removing moribund material and preventing bush encroachment, but is a hazard in a built environment). In a fragmented landscape corridors to other suitable habitat patches are essential for population resilience, but these are designed in the absence of a good understanding of the owl’s dispersal requirements and are likely to become increasingly degraded and fragmented over time.

Mineral extraction is another major driver of habitat destruction since the global appetite for carbon fuels appears inexhaustible and short term economic gains invariably outweigh even the long-term strategic importance of wetland conservation let alone the conservation of owls. While South African legislation compels companies in the mining sector to rehabilitate areas affected by their operations, restoration of natural habitat and ecologically processes is more complex than simply re-vegetating the mine footprint.

Grazing and trampling of wetlands by livestock may be problematic for Grass-Owls where stocking densities are high, but if appropriate rotational grazing schemes are devised the loss of breeding and roosting habitat for owls need not be permanent. This should be an important focal area for agricultural extension officers. In some areas agricultural intensification effectively amounts to habitat destruction e.g. where range-land is converted into large-scale livestock rearing facilities (i.e. feedlots). While such changes may benefit the Barn Owl, Grass-Owls are likely to loose foraging habitat.

Grass-Owls may occur at relatively high densities in areas of intensive crop production provided that breeding and roosting habitat is protected from ploughing, but even where this is the case the wetlands are rarely adequately buffered and degradation as a result of increased nutrient run-off and invasion by weeds seems inevitable. Intensive subsistence agriculture in wetland areas appears to be an increasing problem in-and-around major urban centres in southern Africa where little alternative open land may remain and Grass-Owls are inevitably displaced as a result.

Owl survey

Owl survey, © Craig Whittington-Jones

9) Is electrocution a problem for the owls?
I know of one incident of a Grass-Owl colliding with a powerline, but no electrocution incidents have been reported to me.

10) What other threats do exist for the species?
Roadkills and entanglement on barbed wire fences appear to be the biggest threats after habitat loss and degradation.

11) What gaps in the knowledge about the African Grass Owls do still exist and where should research focus on in the coming years?
The rarity and nocturnal nature of Grass-Owls means that they are relatively challenging to study and as a result we are lacking information on some very fundamental aspects of their biology for example we don’t know what their spatial requirements are, we don’t know why they are present in an area in one year and not the next despite no obvious change in the habitat quality, we don’t know much about their dispersal abilities either in natural or fragmented lanscapes or how readily they re-colonize areas after a disturbance (e.g. fire).

Establishing the foraging requirements of the Grass-Owl is critical for effective conservation planning in areas that are threatened by habitat destruction whether caused by urbanization, mining or some other factor. However, since most Grass-Owls occur in rural areas we also need to determine the appropriate use of fire and grazing as habitat management tools in each biome and develop practical extension tools for use by commercial and subsistence farmers. Further research is also required into road design and maintenance in order to reduce roadkills.

Owl survey

Owl survey, © O. Katumba

12) Are there any conservation programs for the species?
In the 2009 the then Bird of Prey Working Group of the Endangered Wildlife Trust established the African Grass-Owl Task Force. This task force comprises Grass-Owl enthusiasts from a diversity of fields and draws on their expertise to conduct research, gather information and create awareness in order to further conservation of the species. Examples of such initiatives include ongoing research into the spatial requirements of the Grass-Owl, targeted surveys and gathering of historical data in order to map Grass-Owl distribution for inclusion in provincial conservation plans, and the collection of roadkill data for the identification of mortality ‘hotspots’. To date the focus has been on southern Africa, but participation from elsewhere in the species’ range would be welcomed.

13) What other species of birds and other animals could benefit from such conservation programs?
Habitat conservation is a critical component of the task forces’ work and the identification and conservation of wetlands and associated terrestrial foraging habitat and corridors that are of a suitable size and managed appropriately to ensure the persistence of Grass-Owls will benefit a diverse suit of species that are dependant on similar habitat including the African Marsh Harrier, Serval, Giant Bullfrogs and many other rare and common species.

 

Young in hacking cage

Young in hacking cage, © R. Deysel


14) How do you see the future of the African Grass Owl?

For various reasons I don’t hold much hope for the persistence of those Grass-Owl populations in peri-urban areas, but there is room for optimism elsewhere:
1. Regional spatial conservation plans are available for much of the species’ range in South Africa; 2. All levels of government are becoming increasingly aware of the importance of wetland conservation in a water scarce country; 3. Landowners that I have encountered are generally positive about conservation of biodiversity and would probably be receptive to advice on habitat management provided that the realities of their need to make a living from the land were recognized.

15) What was your most amazing experience with the African Grass Owl?
While I feel I should be describing my first Grass-Owl sighting (equally unexpected for me and the owl) or my first discovery of a nest full of downy chicks, the most amazing experience has actually been the response from volunteers. These are not mere twitchers keen for a lead on a tricky tick, but well known names in the raptor and conservation world as well many other less renown but equally dedicated enthusiasts who have generously shared their knowledge and experience and repeatedly donated their time to facilitate and promote research and conservation of the species.

→ 3 CommentsTags: