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]
Causes
editPoisoning
editAnimal 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
editVulture 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
editVulture 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
editOther 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
editNorth Africa
editExcluding 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
editSeven 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
editSouthern 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
editVultures 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
editImage | Common name | Binomial name | Region | 2006 IUCN conservation status | 2021 IUCN conservation status | Population trends |
---|---|---|---|---|---|---|
Hooded vulture | Necrosyrtes monachus | Sub-Saharan Africa | Least concern[22] | Critically endangered[23] | Range-wide declines of 68-79%, several population crashes in west Africa have exceeded 80% declines.[22] | |
Rüppell's vulture | Gyps ruppellii | Sub-saharan Africa and Spain | Least 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 | Sub-Saharan Africa | Least 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 | Gyps coprotheres | Southern Africa | Vulnerable[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 | Torgos tracheliotos | Sub-Saharan Africa and Arabia | Vulnerable[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 | Sub-Saharan Africa | Least 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] | |
Egyptian vulture | Neophron percnopterus | Afro-Eurasia | Endangered[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] | |
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 | |
Lammergeier | Gypaetus barbatus | Afro-Eurasia | Least concern[38] | Near-threatened[39] | 30% declines across its range. European populations are increasing however Asian populations have suffered heavily |
References
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- ^ 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.
- ^ 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
- ^ 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.
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- ^ 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.
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- ^ "Fifteen Griffon Vultures found dead in a well in Morocco". Vulture Conservation Foundation. Retrieved 10 July 2020.
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- ^ "Status of Bearded Vulture in Morocco". MaghrebOrnitho. 28 November 2011. Retrieved 5 September 2022.
- ^ 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.
- ^ 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.
- ^ 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.
- ^ a b 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.
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- ^ "Vulture conservation in South Africa". projectvulture. Retrieved 21 September 2022.
- ^ "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.
- ^ Nyambura, Helen (19 August 2022). "Poachers poison scores of vultures for use in traditional drugs". Bloomberg. Retrieved 8 October 2022.
- ^ 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.
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- ^ 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.
- ^ BirdLife International. (2008). "Gyps africanus". IUCN Red List of Threatened Species. 2008: e.T22695189A28820816. Retrieved 5 September 2022.
- ^ 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.
- ^ BirdLife International. (2008). "Gyps coprotheres". IUCN Red List of Threatened Species. 2008: e.T22695225A28840216. Retrieved 5 September 2022.
- ^ a b 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.
- ^ 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.
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