Featured image: A kettle of vultures both Lappett-faced and White-backed Vultures rising together on a thermal on a rural highway outside of Solitaire in the Namib-Naukluft Park. We saw kettles of vultures several times in the morning. The vultures need to gain height to begin the business of searching for dead animals.
Breadtag Sagas ©: Author Tony, 1 February 2024
This is the fifth article in a series on Southern Africa inspired by a birding trip to Namibia, Botswana and Victoria Falls with Rockjumper and two safaris to Chobe National Park in Botswana with Kalahari Tours and Kruger National Park in South Africa with Lion Roar Safaris.
The articles in order so far are: 1 A Lark in Africa, 2 Welwitschia, 3 Safari to Namibia Part 1, 4 Safari to Namibia, Botswana and Victoria Falls Part 2 and 5 Large Raptors.
Large Raptors on a Birding Safari to Southern Africa
The trip to Africa was a Rockjumper birding tour. Our guide was Greg de Klerk. The tour was for 18-days through Namibia, Botswana to Victoria Falls in Zimbabwe from 28 September to 14 October 2023. We saw many raptors. This article is primarily about the terrestrial meat eating large raptors.
- What is a raptor?
- Large Southern African raptors
- Bird and raptor vision
- Putrid food
- Types of food
- Vultures: Lappett-faced Vulture, White-backed Vulture, Hooded Vulture
- Eagles: Martial Eagle, Verreaux’s Eagle, Bateleur, Tawny Eagle, Black-chested Snake Eagle, Brown Snake Eagle
- Marabou Stork, Secretary Bird, Southern Ground Hornbill
1 What is a Raptor?
A raptor is a bird of prey and may be thought of as a hunter or killer. Although, this is not true of all raptors. Amongst large raptors, some are eaters of carrion or scavengers, whilst others are genuine hunters. Some raptors come from ranks or families of birds that are not considered raptors.
Many birds are insect eaters and often ferocious predators. But, they are not classed as raptors. Some birds that specialise on vertebrate prey, such as frogs lizards, small birds or even snakes and occasionally small mammals are not classed as raptors. So the characterisation is somewhat fuzzy.
The word raptor comes from the Latin verb rapere meaning to seize also to carry off, to violently drag away, with a noun form meaning robbery.
Many birds classed as raptors share a common ancestry. Most raptors are also divided into about 11 common categories, such as eagles, falcons and kestrels, kites, owls etc.
Most raptors are kleptoparasites, that is, steal from one another or other species and from large mammalian predators.
2 Large Southern African Raptors
In looking at Africa’s large raptors that we saw on our birding trip, we will only be examining terrestrial diurnal raptors. We didn’t see any large owls, except Pel’s Fishing Owl. We will look at fish-eating raptors in another article.
Africa has one of the highest numbers of raptor species in the world, exceeded only by the much larger landmass of Asia. There are 83 species of raptors that regularly occur in southern Africa. We saw only some of them.
Southern Africa has five major predators capable of killing large grazing mammals: lions, leopards, spotted hyenas, cheetah and African wild dogs. Also, large numbers of grazing species die from accidents and old age.
The availability of dead animals provides ideal conditions for a large raptor scavenger population, as well as for mammalian ones. Of the large raptors we saw regularly, some but not all, fall into the scavenger category.
The Accipitridae family (hereafter Accipitrids) is by far the most diverse family of diurnal raptors in the world and includes eagles, old world vultures as well as buzzards, kites and hawks. Most of the raptors below are Accipitrids.
3 Bird and Raptor Vision
All birds are descended from dinosaurs (therapods) and have reptilian eye characteristics. All birds have a third eyelid, a protective membrane that covers the whole eye called a nictitating membrane, which provides protection and moistening.
In raptors the nictitating membrane protects the eyes of hunters in diving from wind dust, insects and debris. The membrane may also protect scavengers from gore, putrid material and disease causing microbes.
Raptors have forward facing eyes with good binocular vision. Muscles in the reptilian eye can change the shape of the lens rapidly.
Many hunting raptors have a bony ridge above the eye (giving them a fierce look), which also protects the eyes and shields them from excessive glare. They also have special feathers above and in front of the eye adding further protection from wind and particles.
Birds of prey have high-density receptors to maximise visual acuity. Those of nocturnal raptors (owls) have low numbers of colour receptors but a high density of rod cells for vision in low light.
4 Putrid Food
Scavengers are exposed to blood, gore and rotting carcasses. They need protection from dangerous bacteria and from disease. Supposedly, highly acidic guts and perhaps other digestive factors provide this. Similarly, hyenas and other mammalian scavengers have similar gut protections. The scientific evidence or knowledge for such claims is still sketchy.
Bare skin on the heads and necks of vultures make sense for scavengers who plunge their heads into large carcasses. Feathers and gore presumably don’t mix. There also appears to be convergent evolution in the case of the Marabou Stork, with its vulture like head and neck.
5 Types of Food
Vultures are scavengers, most eagles are hunters but some are scavengers too having mixed-patterns of feeding. The Australian Wedge-tailed Eagle is a scavenger as well as a hunter, as is the American Bald Eagle. Other birds that aren’t classed as raptors are scavengers too, such as, crows and ravens.
Many raptors, especially large ones are kleptoparasites. They are happy to steal from birds of their own and other species and from mammalian predators.
6 The Large Raptors We Saw
Table 1 gives information on the raptors we saw and their sizes, which are outlined below in rough size order. The Australian Wedge-tailed Eagle is included at the bottom for size comparison only.
Large Raptor Information
(M or F)
|No. Days Seen on
|Brown Snake Eagle
|Black-chested Snake Eagle
|Southern Ground Hornbill
|Australian Wedge-tailed Eagle
Most of the information below comes from Robert’s Bird Guide and app.
We saw three species of vultures on our trip. Two regularly, and one the Hooded Vulture, only once at Victoria Falls.
We saw Lappett-faced Vultures on 7 days and White-backed Vultures on 9 days in reasonable numbers: Lappett-faced Vulture numbers were 2, 10, 1, 2, 2, 3, 1 (from 29 September to 12 October) and White-backed Vulture numbers were 20, 1, 4, 8, 1, 1, 20, 2, 1 (from 30 September to 14 October), respectively. We only saw one Hooded Vulture on our last morning on 15 October.
7.1 Indian Vultures
I used to visit India quite regularly from the early 1980s. In my early visits one saw vultures everywhere. In the early 1980s three species of Gyps vultures were very common in India with South Asian populations of around 40 million, in 2017 the populations numbered 19,000.
The population decline of 99% of vultures, which began in the 1990s, was inadvertent. It was caused by an NSAID (nonsteroidal anti-inflammatory drug) called diclofenec given to cattle to relieve arthritis in their last days of life (Diclofenac as the cause was only discovered in 2003). The drug caused kidney failure in vultures. Another NSAID Meloxicam, also used in humans, has no effect on vultures and has mainly replaced Diclofenac.
Diclofenec was banned in India in 2006 (but as with many such things in India, it is still available in rural areas, as is DDT).
The vulture population in India is increasing, but it is a very slow process with such a long-lived animal.
The consequences of the Indian vulture crisis also posed a significant risk to human health and cultural practices. With less than 4% of cattle destined for human consumption the decline in vultures led to a massive increase in animal carcasses, a rise in the feral dog population and the spread of disease and other public health consequences.
7.2 Southern African Vultures
Populations of Lappett-faced Vulture have dropped by 65% over the past 40 years.
Once a common sight throughout African savannas, White-backed Vultures have vanished in many parts as populations have declined by 75% over the past four decades.
The causes of these declines relate to habitat destruction, disappearance of wildlife, but also to poisoning and other factors. Poisoning occurs directly, for example, by poachers wanting to eliminate vultures circling, or indirectly by poisoning carcasses to kill other predators or to control for feral dogs. Killing for meat and other body parts for traditional medicine practices is also rife. The vulture crisis in Africa although slower than in India is just as devastating.
8 Lappett-faced Vulture
The Lappett-faced Vulture (Torgos tracheliotos) or Nubian Vulture is the largest vulture we saw. Lappet-faced Vultures are huge and impressive, especially when pairs chase other vultures off carcasses with their wings spread in a typical threat posture. However, vultures do not seem to compete at waterholes.
Uncommon resident. South African status endangered. Movements little known. Also Israel, Arabian Peninsula, Sub-Saharan Africa. World population estimate 8500 pairs, Africa estimate 3000 pairs.
Savanna and desert. Open woodland in arid- and semi-arid regions including Acacia spp., Shepherd’s-tree, Purple-pod, Cluster-leaf and Mopane.
Feeds on carcasses, tackling skin, tendons and ligaments too tough for other vultures; seldom takes meat and viscera. Dominant over all other vulture species at carcasses (because of size and an aggressive disposition).
Arrives at carcass often later than other vultures. Arrives singly or in pairs, flocks of up to 60 in Botswana.
Gather at waterholes and pans to drink and bathe, sometimes from late morning to afternoon. When bathing, ducks head and uses wings to splash water over body, stands with wings spread then preens. Roosts singly or in pairs in trees.
Large stick nest placed on crown of isolated flat-topped tree.
9 White-backed Vulture
The White-backed Vulture (Gyps africanus) is normally the most numerous vulture on kills in game reserves and protected areas. Subordinate to Lappett-faced Vultures at carcasses, even though they eat different parts of the animal.
Locally common in sparsely inhabited savanna and large game reserves, scarce elsewhere in Southern Africa. Relatively widely spread in sub-Saharan Africa, in West Africa and Central East Africa, as well as southern Africa. Critically endangered in parts of its range.
Scavenger at carcasses; mostly feeds on muscular tissue and viscera (skin and bones generally ignored).
Roosts at night in tall Acacias, often in loose aggregations. Arrives at roost 2-3 h before dark. Resident, but with long distance movements (up to 1426 sq km).
During day may roost on ground. Drinks and bathes regularly around midday. Soars in thermals in pairs. Other birds sometimes join to form stacks, function not understood.
Stick platform nest usually placed on crown of thorn tree.
10 Hooded Vulture
The Hooded Vulture (Necrosyrtes monachus) is critically endangered in sub-Saharan Africa. Usually solitary. Found in tall, tropical woodland and mesic savanna (nutrient poor soils of the Central African plateau), rarely in arid savanna. Primarily a scavenger at carcasses and offal dumps, also takes termites and dung. They are the bottom of the vulture hierarchy at carcasses. Roosts usually singly in the same tree has a smaller home range than the other two vultures. Its nest is a small compact platform of sticks with a well-formed cup, lined with some dry grass and many green leaves.
11 Marabou Stork
The Marabou Stork (Leptoptilos crumenifer) is a massive bird 1.52 m tall and weighs 6-7 kg (male larger). It is not related to vultures or eagles but exhibits unstork-like or vulture-like behaviour and is primarily a scavenger. It has a naked skin head and neck, like vultures (an example of convergent evolution).
Locally fairly common resident, concentrated in game reserves and ranches where carrion and offal readily available.
Both aquatic and terrestrial habitats, favouring open and semi-arid areas.
Scavenger but also opportunistic predator catching mice, birds, fish, frogs, newly hatched crocodiles and insects. Regularly frequents rubbish dumps and abattoirs.
Feeds on carcasses. Subordinate to vultures and large eagles, running in to grab scraps.
Spends many hours resting, mostly standing still. Roosts communally, at traditional sights for 14-16 h, from 1-2 h before sunset and after sunrise.
Colonial, Large stick platform built usually in gomoti fig or baobab often near water.
12 Martial Eagle
The Martial Eagle (Polemaetus bellicosus) is a very large booted eagle. It appears about 4th in average wingspan among living eagles. The Australian Wedge-tailed eagle is larger. We only saw two martial eagles on 8 and 11 October. They are spectacular birds.
Uncommon resident. In South Africa, status endangered. Erroneously believed to kill stock (similar to Wedge-tailed Eagle in Australia previously). Juveniles occasionally will scavenge carcasses. Poisoned and shot.
Savanna, Karoo shrublands and semi-desert.
Diet mainly small mammals such as hares, small antelope and young baboons, also birds and reptiles.
Spends much of day soaring, less often perches on large trees. Defends territory by soaring near intruders. Stoops hard with enough power to knock over a human. Kills by hitting prey or by strangling larger prey once down.
Monogamous. Nest large platform of sticks.
13 Verreaux’s Eagle
Verreaux’s Eagle (Aquila verreauxii) is another magnificent large eagle. We saw only once at Spitzkoppe flying low and soaring above the rock faces. Locally fairly common, but vulnerable. Found in mountainous and rocky areas with large cliffs. Feeds mainly on hyraxes but with a wide range of other mammalian prey including monkeys, young baboons and antelope, also preys on birds and reptiles.
The Bateleur (Terathopius ecaudatis) is a medium-sized eagle native to large areas of sub-Saharan Africa. We saw Bateleurs frequently on 10 days in the following numbers 1,1,1,1,2,1,4,1,2,2. The other frequent victim of poisonings across Africa, the colourful Bateleur spends most of its time on the wing in its typical low gliding flight. Its decline across the continent is concerning.
Widespread in southern Africa and sub-Saharan Africa. Fairly common resident, largely sedentary. Localised to large conservation areas and sparsely inhabited savanna in Southern Africa. Underwent a calamitous range contraction in 20th century due to poisoning.
Savannah, open- and closed-canopy woodlands, incl arid Acacia savannah, Mopane and Miombo favouring broad-leaved woodland with long grass.
Mostly (70-85%) scavenges small animal carcasses, also hunts small mammals, birds and reptiles. Often kleptoparatisised by Tawny Eagle.
Greatly attracted to waterholes: drinking, preening, and loafing. Rarely flies on overcast days. Singly or in pairs, sometimes with juveniles, aggressively defends territory. Frequently perches in trees during the day. Roosts in open trees often as pairs.
Built mainly by male. A platform of small dry sticks.
15 Tawny Eagle
The Tawny Eagle (Aquila rapax) is a large eagle similar in size to a Bateleur. Fairly common in protected areas, but large decreases elsewhere due to poisoning. Habitat Savanna and Karoo Plains. We saw it on four days mostly in Etosha National Park, roughly one per day.
Opportunistic feeder: small mammals, birds, reptiles frogs, fish and insects. Regularly scavenges at carcasses and kleptoparasitises (e.g. Bateleur).
Usually single or in pairs, monogamous, territorial: territory ~ 70 sq km. Roosts from around 2 h before sunset to 2 h after sunrise.
16 Black-chested Snake Eagle
A pretty black and white eagle much smaller than a Martial Eagle. We saw the Black-chested Snake Eagle (Circaetus pectoralis) on five days but only one per day.
Fairly common resident or nomad, movements poorly understood.
Savanna woodland, semi-desert shrublands, grass land and forest margins.
Mainly small snakes (but incl. cobras up to 1.8 m), but also lizards, frogs, rodents and insects
Singly or in loose aggregations (up to 50 birds). Frequently perches on top of tall tree or pole, but also hovers. Roosts on pole or tree top, occasionally on the ground (occasionally communally).
Frequently monogamous. Nest built by both sexes — a saucer shaped platform of small sticks
17 Brown Snake Eagle
The Brown Snake Eagle (Circaetus cinereus) is an uncommon savannah eagle, slightly larger than the Black-chested Snake Eagle with similar habits. We saw the Brown Snake Eagle only on one occasion.
Its food is also mainly snakes including black mamba greater than 2.5 m surprisingly and other reptiles. It hunts mainly from a perch only occasionally whilst soaring.
(Stephen Vol 4)
18 Secretary Bird
The Secretary Bird (Sagittarius serpentarius) is a very unusual raptor. It is in the same Order as all the Accipitrids (eagles, old world vultures etc.) above, but alone in its own family the Sagittaridae. It is mostly terrestrial although quite capable of flying. We only saw one on our whole trip on our way to Etosha striding through the grassland.
Uncommon resident and nomad (esp. juveniles) always at low density (~ 1 pair per 50-150 sq km). Vulnerable.
Grassland, open savannah and Karoo shrublands.
Anything they can overpower, incl. insects (grasshoppers), reptiles (lizards, snakes), birds and their eggs (francolins), and small mammals (mice, hares).Most prey caught on ground with beak, bigger prey killed by downward blows with feet. Strides across short grassland. Occasionally stamping in small areas to disturb or dislodge prey.
Strides, often active in the heat of the day. Flies to roost 1-2 h before dark.
Sometimes solitary usually in pairs. Territorial with home range 20-230 sq km.
Monogamous. Nest built by both sexes. Sticks lined with grass placed on top of thorny tree.
19 Southern Ground Hornbill
We saw eight Southern Ground Hornbill (Bucorvus leadbeateri) four close-up on our drive through Chobe National Park on our last day of travel. These are big amazing birds from a genus that are not raptors. The bare red skin patch on the throat is inflateable. Typically seen waddling slowly through savannah in small flocks.
All hornbills, however, are omnivorous. The ground hornbills are in a separate sub-family from other hornbills.
Uncommon resident. South African status endangered.
Open savanna, grassland and on the edges of cultivation.
Any animal it can overpower, reptiles, insects, frogs squirrels, hares and small birds. Prey picked up, chased or or dug up from soil or dung.
Territorial. Group comprises a dominant pair often with helpers. Members interact often, play is common. Only fly when disturbed or to rest in tree. Groups ascend to roost at dusk wherever they have ended up.
Monogamous cooperative breeder. Nest usually a natural cavity in a live or dead tree. Same site used repeatedly over years.
The behaviour of large raptors is not for the squeamish. These magnificent birds are the apex avian predators and scavengers. Large raptors inhabit an important ecological niche. They are all endangered to some degree because of ignorance, exploitation and range loss. We do know a lot about some aspects of their lives but sometimes not enough about their movements and other aspects of their physiology and ecology.
All birds are under threat but large raptors are important in ways and circumstances that are either unanticipated or that we are unaware of. The demise of vultures in India is a good example because the public health threats were immediate and measurable.
The conservation message is that we can’t afford to lose the diversity of life on this planet, but what is happening is inadvertent sometimes and ignored mostly. The more positive aspect is that because large raptors are noticeable, they are more likely to be conserved. The population recovery of Wedge-tailed Eagles in Australia and Bald Eagles in America are prime examples of this. It is the demise of species that we are less aware of, or more particularly unaware of, that may provide an existential threat to the planet and to the survival of life as we know it.
Key Words: Africa, Southern Africa, birds, raptor, predator, bird of prey, vulture, scavenger, hunter, eagle, owl, Namibia, Botswana, Victoria Falls, South Africa, Marabou Stork, Secretary Bird, Southern Ground Hornbill, kettle of vultures, Lappett-faced Vulture, White-backed Vulture, Solitaire, Namib-Naukluft Park, Etosha National Park, Bwabwata National Park, kleptoparasite, Pel’s Fishing Owl, lions, leopards, spotted hyena, cheetah, African wild dog, Accipitrids, dinosaurs, therapods, third eyelid, nictitating membrane, binocular vision, visual acuity, putrid food, bare skin on head and neck, convergent evolution, Australian Wedge-tailed Eagle, Robert’s Bird Guide, Hooded Vulture, diclofenec, Indian vultures, status, habitat, food, habits, nest, platform of sticks, Sub-Saharan Africa, desert, savanna, semi-arid, woodland, Karoo shrubland, semi-desert, Acacia, Mopane, carrion, carcasses, waterhole, thorn tree, offal, termites, dung, roost, gomoti fig, baobab, Martial Eagle, territory, defends territory, stoop, monogamous, Verreaux’s Eagle, Spitzkoppe, Bateleur, Miombo, drinking, preening, Tawny Eagle, Black-chested Snake Eagle, Brown Snake Eagle, black mamba, dominant pair, helpers, cooperative breeder
Greg Davies, Hugh Chittenden and Ingrid Weiersbye Robert’s Bird Guide Second Edition 2016 and App is the go to place for Southern African birds. It is a wonderful book and App. The main Australian bird apps use Robert’s software.
Chris Stuart Stuart’s Field Guide to the mammals of Southern Africa 2015 and App is a similar Guide to mammals.
Wikipedia also has quite good descriptions of the categories of birds and individual bird species described and is the first place to go to for additional information. There are also many other places to go to on the Internet and elsewhere for further information. I also used Avibirds, the Peregrine Fund, Kruger Park among others.
More Photography of Our Trip
Birds and animals of Southern Africa, Photographs by Stephen Kierniesky
If you want to look more at the birds and other animals of Southern Africa that we saw on the trip, Stephen Kierniesky has posted photographs that can be accessed on Exposure using the following links: