White-backed vulture

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White-backed vulture
2012-white-backed-vulture.jpg
in Etosha National Park
White-backed vulture (Gyps africanus) Kruger.jpg
showing white back
in Kruger National Park
CITES Appendix II  [1]
Scientific classification OOjs UI icon edit-ltr.svg
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Accipitriformes
Family: Accipitridae
Genus: Gyps
Species:
G. africanus
Binomial name
Gyps africanus
Salvadori, 1865
White-backed vulture
  Extant (resident)
  Extant (non-breeding)
  Possibly extant (resident)
  Possibly extinct
  Extinct
in Kruger National Park White-backed Vulture (Gyps africanus) (31053364872).jpg
in Kruger National Park

The white-backed vulture (Gyps africanus) 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. [2]

Contents

Description

The white-backed vulture is a typical vulture, with only down feathers on the head and neck, very broad wings and short tail feathers. It has a white neck ruff. The adult's whitish back contrasts with the otherwise dark plumage. Juveniles are largely dark. This is a medium-sized vulture; its body mass is 4.2 to 7.2 kg (9.3–15.9 lb), it is 78 to 98 cm (31 to 39 in) long and has a 1.96 to 2.25 m (6 ft 5 in to 7 ft 5 in) wingspan. [3] [4] [5]

Distribution and habitat

The white-backed vulture occurs from Senegal, Gambia and Mali in the west, throughout the Sahel region to Ethiopia and Somalia in the east, through East Africa into Mozambique, Zimbabwe, Botswana, Namibia and South Africa in the south. [1] It is the most widespread and common vulture in Africa with an estimated range of 24,300,000 km2 (9,400,000 sq mi), but has undergone rapid population declines in recent years. [1]

Behaviour and ecology

Diet and feeding

Group feeding on a zebra carcass, Upper Lupande GMA, Zambia Vultures Zebra Skeleton Luangwa Zambia Jul23 A7C 06076.jpg
Group feeding on a zebra carcass, Upper Lupande GMA, Zambia

White-backed vultures are obligate scavengers with a high level of specialization on carrion. Their primary food sources are the carcasses of large, grazing animals found in the wooded savannahs where it lives. This includes warthogs, zebras, gazelles, ostriches and even livestock. Their beaks are medium-sized, and not adapted for tearing through tough skin, so they are limited to eating soft tissues, such as the viscera, using a pulling feeding tactic. [6]

White-backed vultures circle through the sky in search of freshly dead animals, often following other scavenger birds and mammalian carnivores to find it. [7] Gyps vultures are considered social vultures which rely heavily on conspecifics to provide information about the position of food and carcasses. [8] The circling flight pattern of vultures is not a signal to other vultures about food, contrary to popular belief. Such signaling could increase competition around limited resources, so vultures instead rely on both personal and social cues to locate carcasses while balancing the risk of competition through selective use of social information in flight decisions. [9]

White-backed vultures feed in groups and are often one of the first vulture species to arrive at a carcass. [10]

Breeding

White-backed Vulture eggs in nest in Atherstone Nature Reserve 1.jpg
White-backed Vulture eggs in a nest in Atherstone Nature Reserve
Vautour africain MHNT.jpg
Egg

White-backed vultures nest in trees. They typically choose tall trees along riparian habitats and show a strong preference for Acacia species. The nests are large, around 1m in diameter, and are made of large sticks and lined with leaves and grasses.

A study which monitored 32 African white-backed vulture nests in the Masai Mara National Reserve during the period 2003 to 2007 showed that the mean nesting success was 59%. [11] Another long-term study conducted in Linyanti, Botswana found that there were rapid declines in nesting numbers during a 10 year period. [12] In 2007, there were 73 breeding pairs nesting in the area with a minimum density of 14.9 nests per 100 square kilometers. By 2017, this declined to 22 breeding pairs nesting and 4.49 nests per 100 square kilometers. In addition to a decrease in the number of active nests in the area, breeding success declined from 62% in 2006 to 37% in 2017.

White-backed vultures face threats from habitat degradation and poaching; as such they have been shown to avoid anthropogenically-disturbed areas when selecting nest sites and protection status is also a strong determinant of site selection. [13]

White-backed vultures have a long breeding cycle. The incubation period is around 8 weeks and the nestling period is about 4–5 months. [14]

Health

The tick Argas theilerae (also known as Theiler's African White-backed vulture argasid) is a parasite of the White-backed vulture. [15]

Conservation

The white-backed vulture has suffered a rapid decline. When it was first assessed in 1988 it was classified as a Least concern species owing to a large range and population. It was reassessed from a Least Concern to Near Threatened species in the 2007 IUCN Red List after the beginnings of a major decline were noticed. [16] In 2012, more information was available about population trends, and the estimates suggested that within the next three generations the white-backed vulture would decrease by 50%. Consequently it was added to the list of Endangered species. [17] In October 2015, it was further uplisted to Critically Endangered because the decline had reached a magnitude that put the vulture at an extreme risk of extinction. [1] A study in 2024 showed that the white-backed vulture population had fallen by 86%. [18]

Studies have also been performed on the white-backed vulture and some species of Asian vultures within the Gyps clade to see the effect of veterinary diclofenac. [19] Regardless of whether the vultures were given an oral or intravenous dose of the substance, the effects were nearly identical and the diclofenac eventually poisoned the subjects. [20]

Another reason for the decline in the number of white-backed vultures is the decrease in the number of their nesting sites, which they construct in trees in savannah areas and which are roughly 1 meter in diameter. There is an inverse relationship between the amount of human activity (farming, ranching, etc.) and the amount of vulture nesting activity in said area, so as the amount of human activity in Africa expands, the number of nesting sites available decreases, putting the vultures in jeopardy. [21] A contributing factor are broader changes in vegetation composition, such as woody plant encroachment, which can decrease hunting efficiency due to limited visibility. [22]

On 20 June 2019, the corpses of 468 white-backed vultures, 17 white-headed vultures, 28 hooded vultures, 14 lappet-faced vultures and 10 cape vultures, altogether 537 vultures, besides 2 tawny eagles, were found in northern Botswana. It is suspected that they died after eating the corpses of 3 elephants that were poisoned by poachers, possibly to avoid detection by the birds, which help rangers to track poaching activity by circling above where there are dead animals. Most of them were new parents, leaving their young orphaned and "ill-equipped" for survival. Vultures are slow breeders, and losing over 400 in a week is a devastating blow for the species. [23] [24] [25] [26]

References

  1. 1 2 3 4 5 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 2022-05-30.
  2. ↑ "white-backed vulture". african geographic. 6 September 2019. Retrieved 20 September 2022.
  3. ↑ "White-backed vulture videos, photos and facts - Gyps africanus". ARKive. Archived from the original on 2012-05-29. Retrieved 2011-05-31.
  4. ↑ Raptors of the World by Ferguson-Lees, Christie, Franklin, Mead & Burton. Houghton Mifflin (2001), ISBN   0-618-12762-3
  5. ↑ "African White-backed Vulture". Oiseaux-birds. Archived from the original on 2014-07-14. Retrieved 2011-10-11.
  6. ↑ Mundy, P.; Butchart, D.; Ledger, J.; Piper, S. (1992). The Vultures of Africa. Randburg, South Africa: Acorn Books.
  7. ↑ Gill, R. "White-Backed Vulture (Gyps africanus)". wildlifeact.com. Wildlife Act. Retrieved 30 July 2020.
  8. ↑ Jackson, A. L.; Ruxton, G. D.; Houston, D. C. (2008). "The effect of social facilitation on foraging success in vultures: a modelling study". Biology Letters. 4 (3): 311–313. doi:10.1098/rsbl.2008.0038. PMC   2610049 . PMID   18364309.
  9. ↑ Sassi, Y.; Nouzières, B.; Scacco, M.; Tremblay, Y.; Duriez, O.; Robira, B. (2024). "The use of social information in vulture flight decisions". Proceedings. Biological Sciences. 291 (2018) 20231729. doi:10.1098/rspb.2023.1729. PMC   10932706 . PMID   38471548.
  10. ↑ Kendall, C.; Virani, M.; Kirui, P.; Thomsett, S.; Githiru, M. (2012). "Mechanisms of Coexistence in Vultures: Understanding the Patterns of Vulture Abundance at Carcasses in Masai Mara National Reserve, Kenya". The Condor. 114 (3): 523–531. doi: 10.1525/cond.2012.100196 . S2CID   55624422.
  11. ↑ Virani, M (2010). "Nesting status of African White-backed Vultures Gyps Africanus in the Masai Mara National Reserve, Kenya". Ostrich. 81 (3): 205–209. Bibcode:2010Ostri..81..205V. doi:10.2989/00306525.2010.519894. S2CID   86549912.
  12. ↑ Leepile, Leungo B. L.; Maude, Glyn; Hancock, Pete; Reading, Richard P.; Bridges, Brian; Hartley, Robyn; Amar, Arjun (2020). "Changes in nesting numbers and breeding success of African White-backed Vulture Gyps africanus in north-central Botswana" . Bird Conservation International. 30 (3): 456–473. doi:10.1017/S0959270920000179. S2CID   219001377.
  13. ↑ Bamford, Andrew J.; Monadjem, Ara; Hardy, Ian C. W. (2009). "Nesting habitat preference of African White-backed Vulture Gyps africanus and the effect of anthropogenic disturbance". Ibis (151): 51–62. doi:10.1111/j.1474-919X.2008.00878.x.
  14. ↑ Kemp, A. C.; Kemp, M. I. (1975). "Observations on the White backed Vulture Gyps africanus in the Kruger National Park, with notes on other avian scavengers". Koedoe (18): 51–68.
  15. ↑ Hoogstraal, Harry; Kaiser, Makram N. (1970-01-15). "The Subgenus Persicargas (Ixodoidea, Argasidae, Argas). 8. A. (P.) theilerae, New Species, a Parasite of the White-Backed Vulture in South Africa". Annals of the Entomological Society of America. 63 (1): 205–210. doi:10.1093/aesa/63.1.205. PMID   5415596.
  16. ↑ See BirdLife International (2007a. b).
  17. ↑ "Recently recategorised species". Birdlife International (2012). Archived from the original on 28 August 2007. Retrieved 15 June 2012.
  18. ↑ "African savanna raptors show evidence of widespread population collapse and a growing dependence on protected areas" (PDF). nature. 15 August 2025. Archived (PDF) from the original on 5 January 2024. Retrieved 15 August 2025.
  19. ↑ Bamford, A.J.; Monadjem, A.; Anderson, M.D.; Anthony, A.; Borello, W.D.; Bridgeford, M.; Bridgeford, P.; Hancock, P.; Howells, B.; Wakelin, J.; Hardy, I.C. (2009). "Trade-offs between specificity and regional generality in habitat association models: a case study of two species of African vulture". Journal of Applied Ecology. 46 (4): 853–859.
  20. ↑ Naidoo V, Wolter K, Cuthbert R, Duncan N. 2009. Veterinary diclofenac threatens Africa's endangered vulture species. Regul Toxicol Pharmacol 53:205–208.
  21. ↑ BAMFORD, A. J., MONADJEM, A., & HARDY, I. C. (2008, September 16). Nesting habitat preference of the African White‐backed Vulture Gyps africanus and the effects of anthropogenic disturbance. Retrieved February 23, 2018, from http://onlinelibrary.wiley.com/doi/10.1111/j.1474-919X.2008.00878.x/full
  22. ↑ Malan, G.; Walker, K. S.; Monadjem, A. (2024). "Finders' eaters: Increasing bush encroachment may shift carcass detection from diurnal avian to nocturnal mammalian scavengers". African Journal of Ecology. doi:10.1111/aje.13262. hdl: 2263/97325 .
  23. ↑ "Over 500 Rare Vultures Die After Eating Poisoned Elephants In Botswana". Agence France-Press . NDTV. 2019-06-21. Archived from the original on 2020-11-08. Retrieved 2019-06-28.
  24. ↑ Hurworth, E. (2019-06-24). "More than 500 endangered vultures die after eating poisoned elephant carcasses". CNN. Archived from the original on 2021-08-03. Retrieved 2019-06-28.
  25. ↑ Solly, Meilan (2019-06-24). "Poachers' Poison Kills 530 Endangered Vultures in Botswana". Smithsonian. Archived from the original on 2021-05-02. Retrieved 2019-06-28.
  26. ↑ Ngounou, B. (2019). "BOTSWANA: Over 500 vultures found dead after massive poisoning". Afrik21. Archived from the original on 2021-01-26. Retrieved 2019-06-28.

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