African vulture crisis

Last updated
A poisoned Eurasian griffon found in the Moroccan Atlas Mountains, 1991 Grifone.jpg
A poisoned Eurasian griffon found in the Moroccan Atlas Mountains, 1991

The African vulture crisis is an ongoing population decline in several Old World vulture species across Africa. Steep population declines have been reported from many locations across the continent since the early 2000s. The causes are mainly poisoning from baited animal carcasses, and the illegal trade in vulture body parts for traditional medicine. [1] Available data suggest that the African vulture crisis may be similar in scale to the Indian vulture crisis, but more protracted and less well documented. [1]

Contents

Causes

Poisoning

Several vultures may gather to feed on a large carcass. Poisoning may kill hundreds Vultures scavenge on an elephant kill - journal.pone.0060797.g001-D.png
Several vultures may gather to feed on a large carcass. Poisoning may kill hundreds

Animal carcasses may be poisoned with toxic pesticide. [1] This may be from deliberate targeting of vultures -- for example, poachers of elephants and rhinos will target vultures to eliminate their tell-tale overhead circling that might expose their illegal activities. [1] Carcasses are also poisoned to kill carnivores blamed for predation of livestock, [1] herbivores blamed for crop destruction [2] and to control feral dog numbers. [1]

Vultures are particularly vulnerable to poisoning because of their foraging behaviors and life history traits. [3] They are obligate scavengers that primarily consume animal carcasses and waste products. Most vulture species forage in large groups, so many individual birds may be poisoned by a single carcass. [4] Even if a poisoned carcass does not kill vultures it can have a harmful effect. Sublethal exposure can affect their reproductive success, behavior, physical characteristics, and immune response. [5] Their long life spans and high trophic level also make them vulnerable to bioaccumulation of poisons over time.

Trade in body parts for traditional medicine

Vulture body parts are used in some cultures to treat physical and mental illnesses. [1] The prices of vulture meat and body parts have been rising, possibly due to an increased demand for these products or a reduced supply of vultures. [6] The African Vulture trade for belief uses varies in importance across the continent with different African cultures participating or not depending on the value of body parts and meat to their traditional medicinal practices. The current level of trade is not sustainable and is contributing to the decline of vulture populations. [7]

Electrocution

Vulture collisions with energy infrastructure and electrocution are relatively common, especially in southern and northern Africa. [1] Efforts to meet United Nations Sustainable Development Goals have led to expansion of electrification programs. However, these do not always implement bird-safe designs that would limit the risks of electrocution and collision. [8]

Other causes

Other threats that contribute to the decline in African vulture populations include habitat degradation and fragmentation, disturbance of nest sites, declines in vulture food supply, and bushmeat consumption by humans. [1] Vulture deaths have also been caused by them visiting wells to drink then becoming waterlogged and drowning. In one incident in Morocco, 15 Eurasian griffons drowned in a well. [9]

Regions affected

North Africa

A lammergeier nestling from Algeria NovitatesZoologicae18 532 Gypaetus barbatus nestling.png
A lammergeier nestling from Algeria

Excluding vagrants, three vulture species still exist in North Africa: the griffon vulture, lammergeier, and Egyptian vulture. Two other species (the cinereous vulture and lappet-faced vulture) have now died out from the region. [10]

The Egyptian vulture is found across North Africa, while the Eurasian griffon is restricted to the Atlas Mountains. The lammergeier is eradicated from the region except Morocco, where it is considered critically endangered. [11]

The most affected species is the Eurasian griffon, [12] though it is apparently common in much of Europe and Asia. Many poisonings in the region are attributed to the use of strychnine, which is heavily regulated by the Moroccan government. [13]

West Africa

Two hooded vultures feeding on a dead dog in Gambia. Their importance in their ecological niche is ridding it of corpses Vultures and dog - The Gambia. West Africa (32740095391).jpg
Two hooded vultures feeding on a dead dog in Gambia. Their importance in their ecological niche is ridding it of corpses

Seven vulture species live in West African countries: the Egyptian vulture, hooded vulture, lappet-faced vulture, palm-nut vulture, Rüppell's vulture, white-backed vulture and white-headed vulture. [14]

West Africa saw some of the largest decreases in vulture numbers, with up to 61% of vultures inside parks and 70% outside parks disappearing in the 30 years between 1970 and 2000. [15] Some populations have declined by almost 97%. [16] In 2020, around 50 hooded vultures were poisoned in Gambia, and between September 2019 and March 2020, 2000 were killed in Guinea-Bissau for traditional medicine. [15] Conservation programs were initiated in these countries and in Senegal, surveying the vulture populations and raising public awareness. [16]

Southern Africa

The endemic cape vulture GypsKolbiKeulemans.jpg
The endemic cape vulture

Southern Africa has the highest species diversity of vultures in the continent, comprising eight species which are the aforementioned Egyptian vulture, hooded vulture, white-backed vulture, white-headed vulture, Rüppell's griffon vulture, lappet-faced vulture, palmnut vulture and the endemic Cape Vulture.

Whilst conservation action has been taking place in the region, [17] the sporadic nature of poisonings and their large death count have dealt heavy blows to vultures in the region.

A recent incident in Kruger National Park involved the poisoned carcass of an African buffalo somewhere in mid-August 2022. It was estimated that 104 White-backed vultures were fatally poisoned, while 20 were harmed. A hyena had also succumbed from the poisoning. [18] It was believed that the poisoning was intentional to collect vulture parts. Currently, the number of white-backed vultures sits at about 7,500 individuals, down from a population that numbered tens of thousands. [19]

An environmental catastrophe effectively occurred in the Chobe National Park, Botswana in 2019, involving the carcasses of three poisoned African bush elephants. A total 537 vultures perished, 468 white-backed vultures, 28 hooded vultures, 17 white-headed vultures, 14 lappet-faced vultures, and 10 cape vultures. Furthermore, 2 tawny eagles succumbed to the poison. For such slow-breeding and long-lived birds, this was a very heavy blow to their population and a major setback to any conservation efforts.

Consequences and implications

Vultures play an essential ecological role in Africa. As a primary scavenger they contribute to the destruction of harmful pathogens and removal of decaying corpses form the environment, which may limit water contamination and the spread of disease from animal carcasses. [20] Falls in vulture numbers in India led to increased numbers of feral dogs and increased rabies incidence, [21] showing a potential threat for human health in Africa.

Affected species

ImageCommon name Binomial name Region2006 IUCN conservation status2021 IUCN conservation statusPopulation trends
Wings of Wonder (5339521000).jpg Hooded vulture Necrosyrtes monachusSub-Saharan AfricaLeast concern [22] Critically endangered [23] Range-wide declines of 68-79%, several population crashes in west Africa have exceeded 80% declines. [22]
Ruppell's vulture, captive, Wildpark Bad Mergentheim, Germany.jpg Rüppell's vulture Gyps ruppelliiSub-saharan Africa and SpainLeast concern [24] Critically endangered [25] Has had the worst range-wide declines, between 85-98% however is more secure in The Gambia and Maasai Mara
White-backed Vulture (Gyps africanus) (32467673583).jpg White-backed vulture Gyps africanusSub-Saharan AfricaLeast concern [26] Critically endangered [27] Declined by 63-89% during the last three generations. Though the most common African vulture, it has suffered the most casualties during the crisis
Cape Vulture - Giant Castle - South-Africa 010002 (15444476446).jpg Cape vulture Gyps coprotheresSouthern AfricaVulnerable [28] Vulnerable [29] Declined by 60-70% from 1992 to 2007, however there have been recent increases in some breeding populations [29]
Lappet-faced vulture 1.jpg Lappet-faced vulture Torgos tracheliotosSub-Saharan Africa and ArabiaVulnerable [30] Endangered [31] Declined by 67-80% over the last three generations in Africa. Arabian populations appear to be stable. [31]
White-headed Vulture (Trigonoceps occipitalis) (46509757432).jpg White-headed vulture Trigonoceps occipitalisSub-Saharan AfricaLeast concern [32] Critically endangered [33] Declined by 60-75% throughout its range, with the worst in Botswana reaching an overall population crash with 87% lost. [33]
Vautour percnoptere au Pont de Gau en Camargue 01.jpg Egyptian vulture Neophron percnopterusAfro-EurasiaEndangered [34] Endangered [35] 91% declines in Africa during the last three generations, about 10% in Europe, stable in the southern Middle East. The biggest declines were recorded in India, owing to the Indian vulture crisis [35]
20191213 Gyps fulvus, Jor Beed Bird Sanctuary, Bikaner 0933 8303.jpg Eurasian griffon vulture Gyps fulvus Europe, Asia, Morocco, and Algeria Least concern [36] Least concern [37] Has declined in North Africa and the Middle East however it is compensated for by major increases in Europe
Quebrantahuesos (Gypaetus barbatus) Bearded Vulture.jpg Lammergeier Gypaetus barbatusAfro-EurasiaLeast concern [38] Near-threatened [39] 30% declines across its range. European populations are increasing however Asian populations have suffered heavily

Related Research Articles

<span class="mw-page-title-main">Vulture</span> Common name for a type of bird

A vulture is a bird of prey that scavenges on carrion. There are 23 extant species of vulture. Old World vultures include 16 living species native to Europe, Africa, and Asia; New World vultures are restricted to North and South America and consist of seven identified species, all belonging to the Cathartidae family. A particular characteristic of many vultures is a bald, unfeathered head. This bare skin is thought to keep the head clean when feeding, and also plays an important role in thermoregulation.

<span class="mw-page-title-main">New World vulture</span> Family of birds

Cathartidae, known commonly as New World vultures or condors, are a family of birds of prey consisting of seven extant species in five genera. It includes five extant vultures and two extant condors found in the Americas. They are known as "New World" vultures to distinguish them from Old World vultures, with which the Cathartidae does not form a single clade despite the two being similar in appearance and behavior as a result of convergent evolution.

<span class="mw-page-title-main">Old World vulture</span> Informal group of birds

Old World vultures are vultures that are found in the Old World, i.e. the continents of Europe, Asia and Africa, and which belong to the family Accipitridae, which also includes eagles, buzzards, kites, and hawks.

<span class="mw-page-title-main">Eurasian griffon vulture</span> Species of bird

The Eurasian griffon vulture is a large Old World vulture in the bird of prey family Accipitridae. It is also known as the griffon vulture, although this term is sometimes used for the genus as a whole. It is not to be confused with the Rüppell's griffon vulture and Himalayan griffon vulture. It is closely related to the white-backed vulture.

<span class="mw-page-title-main">Himalayan vulture</span> Species of bird

The Himalayan vulture or Himalayan griffon vulture is an Old World vulture native to the Himalayas and the adjoining Tibetan Plateau. It is one of the two largest Old World vultures and true raptors. It is listed as Near Threatened on the IUCN Red List. It is not to be confused with the Eurasian griffon vulture, which is a similar and sympatric species.

<span class="mw-page-title-main">White-rumped vulture</span> Species of bird

The white-rumped vulture is an Old World vulture native to South and Southeast Asia. It has been listed as Critically Endangered on the IUCN Red List since 2000, as the population severely declined. White-rumped vultures die of kidney failure caused by diclofenac poisoning. In the 1980s, the global population was estimated at several million individuals, and it was thought to be "the most abundant large bird of prey in the world". As of 2021, the global population was estimated at less than 6,000 mature individuals.

<span class="mw-page-title-main">Indian vulture</span> Species of vulture

The Indian vulture or long-billed vulture is a bird of prey native to the Indian subcontinent. It is an Old World vulture belonging to the family of Accipitridae. It is a medium-sized vulture with a small, semi-bald head with little feathers, long beak, and wide dark colored wings. It breeds mainly on small cliffs and hilly crags in central India and south India.

<span class="mw-page-title-main">Hooded vulture</span> Species of bird

The hooded vulture is an Old World vulture in the order Accipitriformes, which also includes eagles, kites, buzzards and hawks. It is the only member of the genus Necrosyrtes, which is sister to the larger Gyps genus, both of which are a part of the Aegypiinae subfamily of Old World vultures. It is native to sub-Saharan Africa, where it has a widespread distribution with populations in southern, East and West Africa. It is a scruffy-looking, small vulture with dark brown plumage, a long thin bill, bare crown, face and fore-neck, and a downy nape and hind-neck. Its face is usually a light red colour. It typically scavenges on carcasses of wildlife and domestic animals. Although it remains a common species with a stable population in the lower region of Casamance, some areas of The Gambia, and Guinea-Bissau, other regions such as Dakar, Senegal, show more than 85% losses in population over the last 50 years. Threats include poisoning, hunting, loss of habitat and collisions with electricity infrastructure, and the International Union for Conservation of Nature has rated its conservation status as "critically endangered" in their latest assessment (2022). The highest current regional density of hooded vultures is in the western region of The Gambia.

<span class="mw-page-title-main">Lappet-faced vulture</span> Species of bird

The lappet-faced vulture or Nubian vulture is an Old World vulture belonging to the bird order Accipitriformes, which also includes eagles, kites, buzzards and hawks. It is the only member of the genus Torgos. It is not closely related to the superficially similar New World vultures, and does not share the good sense of smell of some members of that family of birds.

<span class="mw-page-title-main">White-backed vulture</span> Species of bird

The white-backed vulture is an Old World vulture in the family Accipitridae, which also includes eagles, kites, buzzards and hawks. It is the most common vulture species in the continent of Africa.

<span class="mw-page-title-main">Cinereous vulture</span> Species of bird

The cinereous vulture is a large raptor in the family Accipitridae and distributed through much of temperate Eurasia. It is also known as the black vulture, monk vulture and Eurasian black vulture. With a body length of 1.2 m, 3.1 m (10 ft) across the wings and a maximum weight of 14 kg (31 lb), it is the largest Old World vulture and largest member of the Accipitridae family.

<span class="mw-page-title-main">Rüppell's vulture</span> Species of bird

Rüppell's vulture, also called Rüppell's griffon vulture, named after Eduard Rüppell, is a large bird of prey, mainly native to the Sahel region and East Africa. The former population of 22,000 has been decreasing due to loss of habitat, incidental poisoning, and other factors. Known also as Rüppell's griffon, Rueppell's griffon, Rüppell's griffin vulture, Rueppell's vulture and other variants, it is not to be confused with a different species, the griffon vulture. Rüppell's vulture is considered to be the highest-flying bird, with confirmed evidence of a flight at an altitude of 11,300 m (37,000 ft) above sea level.

<i>Gyps</i> Genus of birds

Gyps is a genus of Old World vultures that was proposed by Marie Jules César Savigny in 1809. Its members are sometimes known as griffon vultures. Gyps vultures have a slim head, a long slender neck with downy feathers, and a ruff around the neck formed by long buoyant feathers. The crown of their big beaks is a little compressed, and their big dark nostrils are set transverse to the beak. They have six or seven wing feathers, of which the first is the shortest and the fourth the longest.

<span class="mw-page-title-main">Cape vulture</span> Species of bird

The Cape vulture, also known as Cape griffon and Kolbe's vulture, is an Old World vulture in the family Accipitridae. It is endemic to southern Africa, and lives mainly in South Africa, Lesotho, Botswana, and in some parts of northern Namibia. It nests on cliffs and lays one egg per year. In 2015, it had been classified as Endangered on the IUCN Red List, but was down-listed to Vulnerable in 2021 as some populations increased and have been stable since about 2016.

<span class="mw-page-title-main">Red-headed vulture</span> Species of bird

The red-headed vulture, also known as the Asian king vulture, Indian black vulture or Pondicherry vulture, is an Old World vulture mainly found in the Indian subcontinent, with small disjunct populations in some parts of Southeast Asia.

<span class="mw-page-title-main">White-headed vulture</span> Species of bird

The white-headed vulture is an Old World vulture endemic to Africa. Populations have been declining steeply in recent years due to habitat degradation and poisoning of vultures at carcasses. An extinct relative was also present in the Indonesian island of Flores during the Late Pleistocene, indicating that the genus was more widespread in the past.

<span class="mw-page-title-main">Indian vulture crisis</span> Ecological crisis in Indian subcontinent

Nine species of vulture can be found living in India, but most are now in danger of extinction after a rapid and major population collapse in recent decades. In the early 1980s, three species of Gyps vultures had a combined estimated population of 40 million in South Asia, while in 2017 the total population numbered only 19,000.

<span class="mw-page-title-main">Jatayu Conservation Breeding Centre, Pinjore</span> Critically Endangered Bird Breeding Centre in Haryana, India

The Jatayu and Sparrow Conservation Breeding Centre (JCBC), is the world's largest facility for the breeding and conservation of Indian vultures and the house sparrow. It is located within the Bir Shikargah Wildlife Sanctuary in the town of Pinjore in the State of Haryana, India. It is run by the Haryana Forests Department and Bombay Natural History Society with the help of British nature conservation charity Royal Society for the Protection of Birds. It is 8 kilometres (5.0 mi) from Pinjore and covers 5 acres (2.0 ha).

<span class="mw-page-title-main">African vulture trade</span> Use of vulture for various reasons in Sub-Saharan Africa

The African vulture trade involves the poaching, trafficking, and illegal sale of vultures and vulture parts for bushmeat and for ritual and religious use, like traditional medicines, in Sub-Saharan Africa. This illegal trade of vultures and vulture parts is contributing to a population crisis on the continent. In 2017, the IUCN Red List categorized 7 of Africa's 11 vulture species as globally endangered or critically endangered. Recent research suggests that 90% of vulture species declines in Africa may be due to a combination of poisoning and illegal wildlife trade for medicinal use and/or bushmeat. All trade of African vultures is illegal, as these birds are protected by international laws.

References

  1. 1 2 3 4 5 6 7 8 9 Ogada, Darcy; Shaw, Phil; Beyers, Rene; Buji, Ralph; Murn, Campbell; Thiollay, Jean Marc; Beale, Colin; Holdo, Ricardo; Pomeroy, Derek; Baker, Neil; Krüger, Sonja (2015). "Another Continental Vulture Crisis: Africa's Vultures Collapsing Toward Extinction". Conservation Letters. 9 (2): 89–97. doi: 10.1111/conl.12182 . hdl: 10023/8817 . S2CID   54684268.
  2. Safford, Roger; Andevski, Jovan; Botha, Andre; Bowden, Christopher G. R.; Crockford, Nicola; Garbett, Rebecca; Margalida, Antoni; Ramírez, Iván; Shobrak, Mohammed; Tavares, José; Williams, Nick P. (March 2019). "Vulture conservation: the case for urgent action". Bird Conservation International. 29 (1): 1–9. doi: 10.1017/S0959270919000042 . hdl: 10261/217387 . ISSN   0959-2709. S2CID   91384130.
  3. Houston, David C. (1996), "The Effect of Altered Environments on Vultures", Raptors in Human Landscapes, Elsevier, pp. 327–335, doi:10.1016/b978-012100130-8/50033-x, ISBN   9780121001308 , retrieved 2022-07-10
  4. Tsiakiris, Rigas; Halley, John M.; Stara, Kalliopi; Monokrousos, Nikos; Karyou, Chryso; Kassinis, Nicolaos; Papadopoulos, Minas; Xirouchakis, Stavros M. (2021-10-18). "Models of poisoning effects on vulture populations show that small but frequent episodes have a larger effect than large but rare ones". Web Ecology. 21 (2): 79–93. doi: 10.5194/we-21-79-2021 . ISSN   2193-3081. S2CID   239045468.
  5. Gangoso, Laura; Álvarez-Lloret, Pedro; Rodríguez-Navarro, Alejandro. A.B.; Mateo, Rafael; Hiraldo, Fernando; Donázar, José Antonio (February 2009). "Long-term effects of lead poisoning on bone mineralization in vultures exposed to ammunition sources". Environmental Pollution. 157 (2): 569–574. doi:10.1016/j.envpol.2008.09.015. PMID   18995938.
  6. Saidu, Yohanna; Buij, Ralph (2018-03-29). "Traditional medicine trade in vulture parts in northern Nigeria". Vulture News. 65 (1): 4. doi: 10.4314/vulnew.v65i1.1 . ISSN   1606-7479.
  7. McKean, Steven; Mander, Myles; Diederichs, Nicci; Ntuli, Lungile; Mavundla, Khulile; Williams, Vivienne; Wakelin, James (2013). "The impact of traditional use on vultures in South Africa". Vulture News. 65: 15–36. doi: 10.4314/vulnew.v65i1.2 . ISSN   1606-7479.
  8. Oppel, Steffen; Ruffo, Alazar Daka; Bakari, Samuel; Tesfaye, Million; Mengistu, Solomon; Wondafrash, Mengistu; Endris, Ahmed; Pourchier, Cloé; Ngari, Alex; Arkumarev, Volen; Nikolov, Stoyan C. (June 2022). "Pursuit of 'sustainable' development may contribute to the vulture crisis in East Africa". Bird Conservation International. 32 (2): 173–187. doi:10.1017/S0959270921000307. ISSN   0959-2709. S2CID   243002738.
  9. "Fifteen Griffon Vultures found dead in a well in Morocco". Vulture Conservation Foundation. Retrieved 10 July 2020.
  10. "Vultures of Northwest Africa: a complete list". MaghrebOrnitho. 21 August 2014. Retrieved May 17, 2022.
  11. "Status of Bearded Vulture in Morocco". MaghrebOrnitho. 28 November 2011. Retrieved 5 September 2022.
  12. Garrido, Jose Rafael (April 2014). "Poisoning of vultures in Morocco. International Workshop African Vultures & Poison --- Ronda, Málaga, Spain 8--11 April 2014". Academia. Retrieved 5 September 2022.
  13. Amezian, Mohamed; El Khamlichi, Rachid (2016). "Significant population of Egyptian Vulture Neophron percnopterus found in Morocco" (PDF). Ostrich. 87 (1): 73–76. doi:10.2989/00306525.2015.1089334. S2CID   85701482.
  14. Di Vittorio, M.; Hema, E.M.; Dendi, D; et al. (2018). "The conservation status of West African vultures: An updated review and a strategy for conservation". Vie et Milieu-Life and Environment. 68 (1): 33–43.
  15. 1 2 Henriques, Mohamed; Buij, Ralph; Monteiro, Hamilton; Sá, Joaozinho (2020). "Deliberate poisoning of Africa's vultures". Science. 370 (6514): 304. doi:10.1126/science.abd1862. PMID   33060355. S2CID   222412291.
  16. 1 2 "Tackling vulture population declines in West Africa". Bird Life International. 28 October 2021. Retrieved 5 September 2022.
  17. "Vulture conservation in South Africa". projectvulture. Retrieved 21 September 2022.
  18. "More than 100 vultures and a hyena poisoned to death at South Africa's Kruger National Park". Animal Survival International. 16 August 2022. Retrieved 8 October 2022.
  19. Nyambura, Helen (19 August 2022). "Poachers poison scores of vultures for use in traditional drugs". Bloomberg. Retrieved 8 October 2022.
  20. Ogada, Darcy L.; Keesing, Felicia; Virani, Munir Z. (February 2012). "Dropping dead: causes and consequences of vulture population declines worldwide: Worldwide decline of vultures". Annals of the New York Academy of Sciences. 1249 (1): 57–71. doi:10.1111/j.1749-6632.2011.06293.x. PMID   22175274. S2CID   23734331.
  21. Bindra, Prerna Singh. "Declining vulture population can cause a health crisis" . Retrieved 5 September 2022.
  22. 1 2 BirdLife International. (2008). "Necrosyrtes monachus". IUCN Red List of Threatened Species . 2008: e.T22695185A31460087. Retrieved 5 September 2022.
  23. BirdLife International. (2017) [amended version of 2017 assessment]. "Necrosyrtes monachus". IUCN Red List of Threatened Species . 2017: e.T22695185A118599398. doi: 10.2305/IUCN.UK.2017-3.RLTS.T22695185A118599398.en . Retrieved 5 September 2022.
  24. BirdLife International. (2008). "Gyps rueppelli". IUCN Red List of Threatened Species . 2008: e.T22695207A28842119. Retrieved 5 September 2022.
  25. BirdLife International. (2021). "Gyps rueppelli". IUCN Red List of Threatened Species . 2021: e.T22695207A204723468. doi: 10.2305/IUCN.UK.2021-3.RLTS.T22695207A204723468.en . Retrieved 5 September 2022.
  26. BirdLife International. (2008). "Gyps africanus". IUCN Red List of Threatened Species . 2008: e.T22695189A28820816. Retrieved 5 September 2022.
  27. BirdLife International. (2021). "Gyps africanus". IUCN Red List of Threatened Species . 2021: e.T22695189A204461164. doi: 10.2305/IUCN.UK.2021-3.RLTS.T22695189A204461164.en . Retrieved 5 September 2022.
  28. BirdLife International. (2008). "Gyps coprotheres". IUCN Red List of Threatened Species . 2008: e.T22695225A28840216. Retrieved 5 September 2022.
  29. 1 2 BirdLife International. (2021). "Gyps coprotheres". IUCN Red List of Threatened Species . 2021: e.T22695225A197073171. doi: 10.2305/IUCN.UK.2021-3.RLTS.T22695225A197073171.en . Retrieved 5 September 2022.
  30. BirdLife International. (2021). "Torgos tracheliotos". IUCN Red List of Threatened Species . 2021: e.T22695238A205352949. doi: 10.2305/IUCN.UK.2021-3.RLTS.T22695238A205352949.en . Retrieved 5 September 2022.
  31. 1 2 BirdLife International. (2021). "Torgos tracheliotos". IUCN Red List of Threatened Species . 2021: e.T22695238A205352949. doi: 10.2305/IUCN.UK.2021-3.RLTS.T22695238A205352949.en . Retrieved 5 September 2022.
  32. BirdLife International. (2008). "Trigonoceps occipitalis". IUCN Red List of Threatened Species . 2008: e.T22695189A28820816. Retrieved 5 September 2022.
  33. 1 2 BirdLife International. (2021). "Trigonoceps occipitalis". IUCN Red List of Threatened Species . 2021: e.T22695189A204461164. doi: 10.2305/IUCN.UK.2021-3.RLTS.T22695189A204461164.en . Retrieved 5 September 2022.
  34. BirdLife International. (2008). "Neophron percnopterus". IUCN Red List of Threatened Species . 2008: e.T22695180A31604607. Retrieved 5 September 2022.
  35. 1 2 BirdLife International. (2021). "Neophron percnopterus". IUCN Red List of Threatened Species . 2021: e.T22695180A205187871. doi: 10.2305/IUCN.UK.2021-3.RLTS.T22695180A205187871.en . Retrieved 5 September 2022.
  36. BirdLife International. (2008). "Gyps fulvus". IUCN Red List of Threatened Species . 2008: e.T22695219A28833002. Retrieved 5 September 2022.
  37. BirdLife International. (2021). "Gyps fulvus". IUCN Red List of Threatened Species . 2021: e.T22695219A157719127. doi: 10.2305/IUCN.UK.2021-3.RLTS.T22695219A157719127.en . Retrieved 5 September 2022.
  38. BirdLife International. (2008). "Gypaetus barbatus". IUCN Red List of Threatened Species . 2008: e.T22695174A28822726. Retrieved 5 September 2022.
  39. BirdLife International. (2021). "Gypaetus barbatus". IUCN Red List of Threatened Species . 2021: e.T22695174A154813652. doi: 10.2305/IUCN.UK.2021-3.RLTS.T22695174A154813652.en . Retrieved 5 September 2022.