Griffon vulture

Griffon vulture
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Accipitriformes
Family: Accipitridae
Subfamily: Aegypiinae
Genus: Gyps
Species: G. fulvus
Binomial name
Gyps fulvus
(Hablizl, 1783)
Range of griffon vulture

The griffon vulture (Gyps fulvus) is a large Old World vulture in the bird of prey family Accipitridae. It is also known as the Eurasian griffon. It is not to be confused with a different species, Rüppell's griffon vulture (Gyps rueppellii).

Description

The griffon vulture is 93–122 cm (37–48 in) long with a 2.3–2.8 m (7.5–9.2 ft) wingspan. In the nominate race the males weigh 6.2 to 10.5 kg (14 to 23 lb) and females typically weigh 6.5 to 11.3 kg (14 to 25 lb), while in the Indian subspecies (G. f. fulvescens), the vultures average 7.1 kg (16 lb). Extreme adult weights have been reported from 4.5 to 15 kg (9.9 to 33.1 lb), the latter likely a weight attained in captivity.[2][3] Hatched naked, it is a typical Old World vulture in appearance, with a very white head, very broad wings and short tail feathers. It has a white neck ruff and yellow bill. The buff body and wing coverts contrast with the dark flight feathers.

Behaviour

Like other vultures, it is a scavenger, feeding mostly from carcasses of dead animals which it finds by soaring over open areas, often moving in flocks. It establishes nesting colonies in cliffs that are undisturbed by humans while coverage of open areas and availability of dead animals within dozens of kilometres of these cliffs is high.[4][5] It grunts and hisses at roosts or when feeding on carrion.

The maximum recorded lifespan of the griffon vulture is 41.4 years for an individual in captivity.[6]

It breeds on crags in mountains in southern Europe, north Africa, and Asia, laying one egg. Griffon vultures may form loose colonies. The population is mostly resident. Juveniles and immature individuals may migrate far or embark on long-distance movements.[7][8]

Status in Europe and Asia

Griffon vultures eating the carcass of a red deer in the Pyrenees (Spain).
Griffon vulture soaring against a summer sunset.
Griffon vulture in Hai-Bar reserve mount Carmel
Egg

The main cause of the rapid decline in the griffon vulture population is the consumption of poisoned baits set out by people. Wildlife conservation efforts have attempted to increase awareness of the lethal consequences of using illegally poisoned baits through education about the issue.[20]

Physiology

Griffon vultures have been used as model organisms for the study of soaring and thermoregulation. The energy costs of level flight tend to be high, prompting alternatives to flapping in larger birds. Vultures in particular utilize more efficient flying methods such as soaring. Compared to other birds, which elevate their metabolic rate to upwards of 16 times their basal metabolic rate in flight,[21] soaring griffon vultures expend about 1.43 times their basal metabolic rate in flight. Griffon vultures are also efficient flyers in their ability to return to a resting heart rate after flight within ten minutes.[22]

As large scavengers, griffon vultures have not been observed to seek shelter for thermoregulation. Vultures use their bald heads as a means to thermoregulate in both extreme cold and hot temperatures. Changes in posture can increase bare skin exposure from 7% to 32%. This change allows for the more than doubling of convective heat loss in still air.[23] Griffon vultures have also been found to tolerate increased body temperatures as a response to high ambient temperatures. By allowing their internal body temperature to change independently of their metabolic rate, griffon vultures minimize their loss of water and energy in thermoregulating.[24] One study in particular (Bahat 1995) found that these adaptations have allowed the Griffon vulture to have one of the widest thermal neutral zones of any bird.[25]

Intraspecific competition

A mounted specimen alongside numerous other birds of prey, Natural History Museum, London

In respect to varying age ranges, the griffon vultures evidently show no difference in feeding rates. Inevitably, as resource availability increases, feeding rates tend to follow the same pattern. Upon studying the reintroduction of this species and its impact on the intraspecific competition, old adults are more inclined to display aggressive behavior and signs of dominance in comparison to the other age ranges. In terms of comparing the male and female sexes, there are no observed differences in competitive behaviors. Lastly, the reintroduced individuals of the species and the wild-bred do not differ in dominance or feeding rate despite the differences in upbringing.[26]

References

  1. BirdLife International (2013). "Gyps fulvus". IUCN Red List of Threatened Species. Version 2013.2. International Union for Conservation of Nature. Retrieved 26 November 2013.
  2. Ferguson-Lees, James; Christie, David A. (2001). Raptors of the World. Illustrated by Kim Franklin, David Mead, and Philip Burton. Houghton Mifflin. ISBN 978-0-618-12762-7.
  3. Ali, Sálim (1996). The Book of Indian Birds (12th ed.). Bombay: Bombay Natural History Society. ISBN 0-19-563731-3.
  4. Gavashelishvili, A.; McGrady, M.J. (2006). "Breeding site selection by bearded vulture (Gypaetus barbatus) and Eurasian griffon (Gyps fulvus) in the Caucasus". Animal Conservation. 9 (2): 159–170. doi:10.1111/j.1469-1795.2005.00017.x.
  5. Gavashelishvili, A.; McGrady, M.J. (2006). "Geographic information system-based modelling of vulture response to carcass appearance in the Caucasus". Journal of Zoology. 269 (3): 365–372. doi:10.1111/j.1469-7998.2006.00062.x.
  6. Carey, James R.; Judge, Debra S. "Longevity Records: Life Spans of Mammals, Birds, Amphibians, Reptiles, and Fish". Monographs on Population Aging, 8. Odense University Press. Retrieved 13 September 2011.
  7. Gavashelishvili, A. (2005). "Vulture movements in the Caucasus". Vulture News. 53: 28–29. doi:10.4314/vulnew.v53i1.37634.
  8. McGrady, M.J.; Gavashelishvili, A. (2006). "Tracking vultures from the Caucasus into Iran" (PDF). Podoces. 1 (1/2): 21–26.
  9. Ettinger, Powell (2008). "Griffon vultures on Cres Island - Croatia". Wildlife Extra. External link in |website= (help)
  10. http://www.independent.co.uk/environment/guernsey-welcomes-its-latest-resident-the-griffon-vulture-710465.html
  11. "Gänsegeier in Flandern" [Griffon vultures in Flanders]. n-tv.de (in German). 18 June 2007. Retrieved 20 June 2007. External link in |website= (help)
  12. "Großer Geier-Einflug über Deutschland" [Large vulture flight over Germany] (in German). Handelsblatt. 30 June 2006. Retrieved 20 June 2007.
  13. "Gänsegeier in Deutschland" [Griffon vultures in Germany]. n-tv.de (in German). 22 June 2006. Retrieved 25 June 2007. External link in |website= (help)
  14. "Prehistoric flute in Germany is oldest known". Associated Press. Retrieved 24 June 2009.
  15. "Earliest musical tradition documented in SW Germany". Science Centric. Retrieved 24 June 2009. External link in |website= (help)
  16. "Canyon of river Trešnjica".
  17. "Zlatar tourist organization, Serbia".
  18. MacKenzie, Debora (1 June 2007). "Starving vultures switch to live prey". New Scientist. Retrieved 20 June 2007.
  19. "Woman Eaten By Vultures After Fall From Cliff". inquisitr.com. 6 May 2013. External link in |website= (help)
  20. Demerdzhiev, Dimitar; Hristov, Hristo; Dobrev, Dobromir; Angelov, Ivaylo and Kurtev, Marin (2014). "Long-term population status, breeding parameters and limiting factors of the griffon vulture (Gyps fulvus Hablizl, 1783) population in the Eastern Rhodopes, Bulgaria." Acta Zoologica Bulgarica, 66(3), 373-384. http://www.acta-zoologica-bulgarica.eu/downloads/acta-zoologica-bulgarica/2014/66-3-373-384.pdf
  21. Gavrilov, V. M. (2011-11-26). "Energy expenditures for flight, aerodynamic quality, and colonization of forest habitats by birds". Biology Bulletin. 38 (8): 779–788. ISSN 1062-3590. doi:10.1134/S1062359011080024.
  22. Duriez, Olivier; Kato, Akiko; Tromp, Clara; Dell'Omo, Giacomo; Vyssotski, Alexei L.; Sarrazin, François; Ropert-Coudert, Yan (2014-01-15). "How Cheap Is Soaring Flight in Raptors? A Preliminary Investigation in Freely-Flying Vultures". PLOS ONE. 9 (1): e84887. ISSN 1932-6203. PMC 3893159Freely accessible. PMID 24454760. doi:10.1371/journal.pone.0084887.
  23. Ward, Jennifer; McCafferty, Dominic J.; Houston, David C.; Ruxton, Graeme D. (2008-04-01). "Why do vultures have bald heads? The role of postural adjustment and bare skin areas in thermoregulation". Journal of Thermal Biology. 33 (3): 168–173. doi:10.1016/j.jtherbio.2008.01.002.
  24. Prinzinger, Roland; Nagel, B.; Bahat, O.; Bögel, R.; Karl, E.; Weihs, D.; Walzer, C. (2002-10-01). "Energy metabolism and body temperature in the Griffon Vulture (Gyps fulvus) with comparative data on the Hooded Vulture (Necrosyrtes monachus) and the White-backed Vulture (Gyps africanus)". Journal für Ornithologie. 143 (4): 456–467. ISSN 1439-0361. doi:10.1046/j.1439-0361.2002.02039.x.
  25. Bahat O (1995) Physiological adaptations and foraging ecology of an obligatory carrion eater - the griffon vulture (Gyps fulvus) [PhD thesis]. Tel Aviv: Tel-Aviv University. 102 p.
  26. Bose, Michela; Sarrazin, Francois (July 2007). "Competitive behaviour and feeding rate in a reintroduced population of Griffon Vultures Gyps fulvus". British Ornithologists’ Union. 149 (3): 490–501. doi:10.1111/j.1474-919X.2007.00674.x. Retrieved 1 May 2015.

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