Diet and Foraging

The Eurasian Griffon is an obligate scavenger that feeds on carcasses, mostly of domestic or wild ungulates; only occasionally will it kill an animal as prey. It depends on thermal updrafts for flight, and is most active when hungry, flying greater distances and moving farther from the roost than when it is satiated. To avoid starvation, it changes its strategy based on how many days it has gone without food. For the first few days without food, to increase its chances of finding food it travels farther, increasing its maximal displacement, and flying at higher altitudes. In the days that follow, it minimizes energy expenditure by decreasing these three measures. The Eurasian Griffon can survive periods of food deprivation of at least 31 consecutive days. It forages in loose groups and is drawn to a foraging site by other vultures that have located food, as indicated by a change in their flight style. When a bird locates food, it will soar low then descend vertically to the carcass flapping its wings with its feet hanging down. At the carcass, the Eurasian Griffon follows a despotic dominance hierarchy that lends priority to adults over subadults and juveniles, and individuals fight to keep positions close to the carcass and to defend pieces of food. It can also receive information about the location of carrion in communal roosts.

Main Foods Taken

The Eurasian Griffon mainly feeds on carcasses (typically ungulates) abandoned by predators, domestic or wild animals killed by disease or accident, livestock carcasses deposited on dunghills, food stolen from other species, and occasionally animals it has killed itself (272 Donázar, J. A. (1993). Los Buitres Ibéricos: Biología y Conservación. J. M. Reyero, Madrid, Spain. Close ). Consumption of stranded carcasses along the sea coast was recorded near Oriñón, Cantabria (Spain; 273 González Morales, J. A. (1969). Una colonia de Gyps fulvus en la costa cantábrica. Ardeola 15: 128. Close ) and on Cres Island (Croatia; 85 Perco, F., S. G. Toso, G. Sušić, and M. Apollonio (1983). Initial data for a study on the status, distribution and ecology of the Griffon vulture, Gyps fulvus fulvus (Hablizl, 1783) in the Kvarner Archipelago. Larus 33–35: 99–134. Close ). In the Eastern Rhodope Mountains (Bulgaria and Greece), 60.2% of the its diet was animals killed by predators (gray wolf [Canis lupus], golden jackal [Canis aureus], and feral dogs), 37.6% that died of natural causes, and 2.2% by poaching (n = 93; 274 Arkumarev, V., D. Dobrev, A. Stamenov, N. Terziev, A. Delchev, and S. Stoychev (2020). Using GPS and accelerometry data to study the diet of a top avian scavenger. Bird Study 67(3): 300–310. Close ). In Gir National Park (India), 45.87% of recorded carcasses had died of natural causes and 54.12% by predation of other animals (n = 194; 215 Grubh, R. B. (1978). The Griffon vultures (Gyps bengalensis, G. indicus & G. fulvus) of Gir Forest: their feeding habits and the nature of association with the asiatic lion. The Journal of the Bombay Natural History Society 75: 1058–1068. Close ).

Movements to follow cattle drives, both in fall and spring, were observed in Tajikistan, Kazakhstan, and Turkmenistan (156 Dementiev, G. P. (1951). Otryad khishchnyye ptitsy Acipitres ili Falconiformes. In Ptitsy Sovetskogo Soyuza (G. P. Dementiev and N. A. Gladkov, Editors), Tom 1. Sowjetskaja Nauka, Moskwa, Russia. pp. 70–341. Close ). In the Sierras de Cazorla, Segura y Las Villas Natural Park (southeastern Spain), 63% of GPS tracked Eurasian Griffon (n = 30), mainly non-breeding birds and females, increased foraging activity in the pasturelands occupied by transhumant herds of domestic ungulates from June–November (275 Aguilera-Alcalá, N., E. Arrondo, R. Pascual-Rico, Z. Morales-Reyes, J. M. Gil-Sánchez, J. A. Donázar, M. Moleón, and J. A. Sánchez-Zapata (2022). The value of transhumance for biodiversity conservation: vulture foraging in relation to livestock movements. Ambio 51:1330–1342. Close ).

The saiga antelope (Saiga tatarica), a once-abundant migratory species of the Eurasian Steppe, is now endangered, in part because of its susceptibility to disease; in west-central Kazakhstan, groups of Eurasian Griffon and Cinereous Vulture (Aegypius monachus) were observed during July and August 1958 at several locations in association with the beginning of a mass epizootic mortality event in saiga antelope herds. On 21 August, Eurasian Griffons were observed in one of these herds of sick saigas; the birds were sitting on the ground at a distance, waiting for the infected animals to die (115 Korelov, M. N. (1962). Otryad khishchnyye ptitsy – Falconiformes. In Ptitsy Kazakhstana (V. F. Gavrin, I. A. Dolgushin, M. N. Korelov, and M. A. Kuzmina, Editors). Tom 2. Izdatel'stvo Akademii Nauk Kazakhskoy SSR, Alma-Ata. pp. 488–707. Close ).

In June 2003, three Eurasian Griffon were recorded in the Netherlands preying upon 28 White Stork (Ciconia ciconia) nestlings aged 2–8 weeks from a total of 18 nests, from the De Lokkerij breeding colony (6 nests) and ten other sites located 0.1–8.2 km away (276 Koopman, F. (2004). Vale Gieren Gyps fulvus versus Ooieveaars Ciconia ciconia. Het Vogeljaar 52(1): 3–8. Close ).

Microhabitats for Foraging

Foraging Eurasian Griffon in Spain showed a preference for areas with natural and semi-natural vegetation (277 Arrondo, E., M. Moleón, A. Cortés-Avizanda, J. Jiménez, P. Beja, J. A. Sánchez-Zapata, and J. A. Donázar (2018). Invisible barriers: Differential sanitary regulations constrain vulture movements across country borders. Biological Conservation 219: 46–52. Close ). On Crete (Greece), it foraged mainly over open areas with bare rocks and Mediterranean scrubland (278 Xirouchakis, S., and G. Andreou (2009). Foraging behaviour and flight characteristics of Eurasian griffons Gyps fulvus in the island of Crete, Greece. Wildlife Biology 15(1): 37–52. Close ). In Kazakhstan, it avoided forested areas and river valleys, preferring instead to forage over highland and lowland steppe and, less often, in deserts (115 Korelov, M. N. (1962). Otryad khishchnyye ptitsy – Falconiformes. In Ptitsy Kazakhstana (V. F. Gavrin, I. A. Dolgushin, M. N. Korelov, and M. A. Kuzmina, Editors). Tom 2. Izdatel'stvo Akademii Nauk Kazakhskoy SSR, Alma-Ata. pp. 488–707. Close ). It selects foraging habitat in response to the spatial and temporal distribution of food; on Crete and in Kazakhstan, it foraged in lower areas during winter and shifted to higher habitat during summer (201 Xirouchakis, S. M., and M. Mylonas (2004). Griffon vulture (Gyps fulvus) distribution and density in Crete. Israel Journal of Zoology 50: 341–354. Close , 279 Xirouchakis, S. M. (2007). Seasonal and daily activity pattern in Griffon Vulture (Gyps fulvus) colonies on the island of Crete (Greece). Ornis Fennica 84: 39–46. Close ; Katzner, personal communication).

Foraging locations (n = 24,302) recorded from 60 GPS-tracked birds in Spain between 2014–2016 were concentrated in agroforestry areas, areas with higher livestock density, natural grasslands, transitional woodland-shrub, sclerophyllous vegetation, and broad-leaved forests. It tended to avoid, or forage less often, in non-irrigated arable land, permanent irrigated land, and olive groves (277 Arrondo, E., M. Moleón, A. Cortés-Avizanda, J. Jiménez, P. Beja, J. A. Sánchez-Zapata, and J. A. Donázar (2018). Invisible barriers: Differential sanitary regulations constrain vulture movements across country borders. Biological Conservation 219: 46–52. Close ).

The use of different foraging microhabitats seems to depend on the abundance of carcasses in the wild. Birds will also use supplemental feeding stations; such supplemental feeding stations were established to compensate for the scarcity of carrion in the wild and thus contribute to the recovery of populations (see Management). In the Grands Causses (France), GPS-tracked adult birds selected feeding stations more often than they did other habitats throughout the year. In one study, adults showed a preference in spring and summer for small, unpredictable feeding stations rather than large, highly predictable ones; preference for small feeding stations could be related to an attempt to reduce intraspecific competition. Open habitats were also selected; forested areas and urbanized areas were avoided (280 Monsarrat, S., S. Benhamou, F. Sarrazin, C. Bessa-Gomes, W. Bouten, and O. Duriez (2013). How predictability of feeding patches affects home range and foraging habitat selection in avian social scavengers? PLOS One 8(1): e53077. Close ). Most feeding events (71.4%) of 47 GPS-tracked individuals in Israel and Jordan occurred at a feeding station, but the birds also searched for food elsewhere (281 Spiegel, O., R. Harel, W. M. Getz, and R. Nathan (2013). Mixed strategies of griffon vultures’ (Gyps fulvus) response to food deprivation lead to a hump-shaped movement pattern. Movement Ecology 1: 5. Close ).

In the Eastern Rhodopes Mountains (Bulgaria and Greece), most feeding events of 11 GPS-tracked birds occurred at carcasses of free-range livestock and game found in the wild (77.4%), and only 22.6% were at feeding stations (n = 1,036). However, there was seasonal variation: 56.5% ± 16.1 SD of the feeding events in winter were at feeding stations, decreasing to 30.4% ± 10 SD in spring, 19.82% ± 7.8 SD in summer, and 29.56% ± 11.4 SD in autumn. Higher use of feeding stations was observed in breeding birds during the pre-breeding period and during incubation. In addition to seasonal differences, birds would also use supplemental feeding stations during periods of bad weather when flight was difficult, such as during periods of rain or high wind, while they would use carrion at wild sites during warm weather (282 Arkumarev, V., D. Dobrev, A. Stamenov, N. Terziev, A. Delchev, and S. Stoychev (2021). Seasonal dynamics in the exploitation of natural carcasses and supplementary feeding stations by a top avian scavenger. Journal of Ornithology Close ).

Food Capture and Consumption

Like other species of the genus Gyps, the Eurasian Griffon is considered a gulper, a mode of feeding by which they swallow large chunks of soft tissues from the carcasses (283 Hertel, F. (1994). Diversity in body size and feeding morphology within past and present vulture assemblages. Ecology 75(4):1074–1084. Close ), with unique features to its bill, skull, and mandible that are adapted to feed on the muscle and viscera of carrion (283 Hertel, F. (1994). Diversity in body size and feeding morphology within past and present vulture assemblages. Ecology 75(4):1074–1084. Close , 284 Alvarez, F., L. Arias de Reyna, and F. Hiraldo (1976). Interactions among avian scavengers in southern Spain. Ornis Scandinavica 7:215–226. Close , 285 Houston, D. C. (1983). The adaptive radiation of the griffon vultures. In Vulture Biology and Management (S. R. Wilbur and J. A. Jackson, Editors), University of California Press, Berkeley, CA, USA. pp. 360–363 Close , 286 König, C. (1983). Interspecific and intraspecific competition for food among Old World vultures. In Vulture Biology and Management (S. R. Wilbur and J. A. Jackson, Editors), University of California Press, Berkeley, CA, USA. pp. 153–171. Close ). Specifically, the skull and first two vertebrae of the Eurasian Griffon are long and narrow, with specializations in the morphology of the atlas-axis complex and the neck musculature that allow it to adopt specific postures while feeding (287 Böhmer, C., J. Prevoteau, O. Duriez, and A. Abourachid (2020). Gulper, ripper and scrapper: anatomy of the neck in three species of vultures. Journal of Anatomy 236:701–723. Close ). Typical feeding behavior includes pulling with the bill, inserting the head through an opening, tearing skin, and tugging out fibers (284 Alvarez, F., L. Arias de Reyna, and F. Hiraldo (1976). Interactions among avian scavengers in southern Spain. Ornis Scandinavica 7:215–226. Close ).

The number and speed of feeding pecks at carcasses differs among species, with some having similar feeding rates. In comparison with other Spanish scavengers, the Eurasian Griffon is a balanced scavenger, as compared to the Cinereous Vulture (Aegypius monachus) and Common Raven (Corvus corax), which will peck only a few times over a moderate time; in the Eurasian Griffon, the mean number of feeding pecks was 5.7 pecks/min ± 0.9 SD (n = 72) in adults, and 4.9 pecks/min ± 0.4 SD (n = 128) in non-adults (288 Moreno-Opo, R., A. Trujillano, and A. Margalida (2016). Behavioral coexistence and feeding efficiency drive niche partitioning in European avian scavengers. Behavioural Ecology 27:1047–1059. Close ).

Visual acuity in Gyps vultures is high in comparison to most other raptors (289 Potier, S. (2020). Visual Adaptations in Predatory and Scavenging Diurnal Raptors. Diversity 12:400. Close ); the Eurasian Griffon, as an active forager, uses sight to search for carrion. One individual's visual acuity measured an estimated 104 cycles per degree of visual angle, i.e., it had the ability to distinguish 104 black and 104 white vertical bars in one degree of visual angle (290 Fischer, A. B. (1969). Laboruntersuchungen und Freilandbeobachtungen zum sehvermögen und Verhalten von Altweltgeiern. Zoologische Jahrbücher. Abteilung für Systematik, Ökologie und Geographie der Tiere 96:81–132. Close ). The Eurasian Griffon's field of vision contains a small binocular region (21º) and blind areas above, below, and behind the head (291 Martin, G. R., S. J. Portugal, and C. Murn (2012). Visual fields, foraging and collision vulnerability in Gyps vultures. Ibis 154(3): 626–631. Close ). Average flight altitude was 462 m in Israel and 338 m in France (267 Harel, R., O. Duriez, O. Spiegel, J. Fluhr, N. Horvitz, W. M. Getz, W. Bouten, F. Sarrazin, O. Hatzofe, and R. Nathan (2016). Decision-making by a soaring bird: time, energy and risk considerations at different spatio-temporal scales. Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences, 371(1704): 20150397. Close ).

The Eurasian Griffon forages in loose groups to locate large carcasses of ungulates (292 van Overveld, T., G. Blanco, M. Moleón, A. Margalida, J. A. Sánchez-Zapata, M. de la Riva, and J. A. Donázar (2020). Integrating vulture social behavior into conservation practice. Condor: Ornithological Applications 122:1–20. Close ). A breeding pair will take turns foraging while the other remains on the nest; however, it is unknown whether the foraging member searches for food alone or whether it joins an existing group to feed. The mean number of daylight hours that passed between when an animal died and when the Eurasian Griffon began feeding on the carcass was 30.76 h ± 11.38 SD in the Caucasus (194 Gavashelishvili, A., and M. J. McGrady (2006). Breeding site selection by bearded vulture (Gypaetus barbatus) and Eurasian Griffon (Gyps fulvus) in the Caucasus. Animal Conservation 9: 159–170. Close ), but a carcass was found in as little as two hours in one instance in Extremadura (Spain; 293 König, C. (1974). Zum verhalten spanischer Geier an Kadavern. Journal für Ornithologie 115(3):289–320. Close ). In the Spanish Pyrenees, carcasses were detected mainly by Eurasian Griffon, faster in open landscapes (15.4 h ± 19.17 SD) than in shrublands (24.56 h ± 37.34 SD; 294 Oliva-Vidal, P., E. Sebastián-González, and A. Margalida (2022). Scavenging in changing environments: woody encroachment shapes rural scavenger assemblages in Europe. Oikos e09310 Close ).

Foraging Eurasian Griffon learn the location of carrion by following other individuals that may be flying toward a carcass or by noticing where other vultures sink vertically to the ground (1 Tristram, H. B. (1859). On the ornithology of Northern Africa. Ibis 1:277–301. Close , 295 Cortés-Avizanda, A., R. Jovani, J. A. Donázar, and V. Grimm (2014). Bird sky networks: How do avian scavengers use social information to find carrion? Ecology 95(7): 1799–1808. Close ). On Crete (Greece), individuals that had located food (n = 23) either soared low to the ground or—with dangling feet or flapping flight—sank vertically to the carcass (278 Xirouchakis, S., and G. Andreou (2009). Foraging behaviour and flight characteristics of Eurasian griffons Gyps fulvus in the island of Crete, Greece. Wildlife Biology 15(1): 37–52. Close ). Another method of learning the location of carrion takes place at communal roosts (17 Elosegi, I. (1989). Vautour fauve (Gyps fulvus), Gypaete barbu (Gypaetus barbatus), percnoptere d’Egypte (Neophron percnopterus): Synthèse bibliographique et recherches. Acta Biologica Montana, Série documents de travail 3: 1–278. Close ): a Eurasian Griffon that has fed on a carcass, upon returning to the roost to sleep, provides information to other vultures. The mechanism of information transfer is unknown, but it is likely based on visual cues such as bloody plumage, a full crop, or a particular flight behavior (296 Harel, R., O. Spiegel, W. M. Getz, and R. Nathan (2017). Social foraging and individual consistency in following behaviour: testing the information centre hypothesis in free-ranging vultures. Proceedings of the Royal Society B: Biological Sciences 284: 20162654. Close ). Some vultures that fed on carrion (38%) returned to the site the next day, and often another individual followed immediately (within 2 min) and at close range (1.61 km ± 0.83 SD; 296 Harel, R., O. Spiegel, W. M. Getz, and R. Nathan (2017). Social foraging and individual consistency in following behaviour: testing the information centre hypothesis in free-ranging vultures. Proceedings of the Royal Society B: Biological Sciences 284: 20162654. Close ).

In addition to reliance on conspecifics, the unpredictable availability of carrion in the wild can facilitate interspecific interactions. The Eurasian Griffon located wild carrion quicker when small scavenger species were already present at a feeding site, and small scavengers were able to feed successfully once the Eurasian Griffon dismembered the carrion. This mutual benefit was not observed at supplemental feeding stations, where the Eurasian Griffon arrived earlier and, by their sheer numbers, excluded smaller scavengers from this predictable food source (297 Cortés-Avizanda, A., R. Jovani, M. Carrete, and J. A. Donázar (2012). Resource unpredictability promotes species diversity and coexistence in an avian scavenger guild: a field experiment. Ecology 93(12): 2570–2579. Close ). It can also receive benefits from other large scavengers; in Gir National Park (India), carcasses consumed by the White-rumped Vulture (Gyps bengalensis), Indian Vulture (Gyps indicus), and Eurasian Griffon had either been opened by lions, leopards, hyenas, jackals, or by humans (215 Grubh, R. B. (1978). The Griffon vultures (Gyps bengalensis, G. indicus & G. fulvus) of Gir Forest: their feeding habits and the nature of association with the asiatic lion. The Journal of the Bombay Natural History Society 75: 1058–1068. Close ).

Foraging distances of the Eurasian Griffon from several populations (French Pyrenees, Ebro valley, Sierra de Cazorla, Cataluña, and Cádiz province) usually were (92.1%) < 350 km from the nest or activity center (n = 106 tracked birds); however, foraging movements of 32 of those individuals were recorded as far as 800 km, at open oak habitats of southwestern Iberia. Long distance movements were mostly carried out by females in summer (298 Delgado‐González, A., A. Cortés‐Avizanda, D. Serrano, E. Arrondo, O. Duriez, A. Margalida, M. Carrete, P. Oliva‐Vidal, E. Sourp, Z. Morales‐Reyes, I. García‐Barón, M. de la Riva, J. A. Sánchez‐Zapata, and J. A. Donázar (2022). Apex scavengers from different European populations converge at threatened savannah landscapes. Scientific Reports 12:2500. Close ). Several studies indicate that the distance traveled while foraging appears to be related to the abundance of carrion in the wild. The mean distance flown daily by foraging birds was 160 km in Israel and 141 km in France (267 Harel, R., O. Duriez, O. Spiegel, J. Fluhr, N. Horvitz, W. M. Getz, W. Bouten, F. Sarrazin, O. Hatzofe, and R. Nathan (2016). Decision-making by a soaring bird: time, energy and risk considerations at different spatio-temporal scales. Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences, 371(1704): 20150397. Close ). In the Eastern Rhodope Mountains (Bulgaria and Greece), on average, 11 GPS-tracked immature birds traveled longer distances on days they fed on carcasses in the wild (96.7 km ± 57.4 SD) than on days they fed at feeding stations (70.6 km ± 59.7 SD) or on days with no recorded feeding (70.8 km ± 59.8 SD; 282 Arkumarev, V., D. Dobrev, A. Stamenov, N. Terziev, A. Delchev, and S. Stoychev (2021). Seasonal dynamics in the exploitation of natural carcasses and supplementary feeding stations by a top avian scavenger. Journal of Ornithology Close ).

The Eurasian Griffon can endure a varying number of days between feedings. One study of GPS-tracked birds conducted in Israel reported periods of 7–10 d between successive feedings (299 Bahat, O., A. Kaplan, Y. Baidatz, L. Kaplan, I. Choshniak, and D. Houston (1993). Radio-tracking a juvenile Griffon Vulture (Gyps fulvus) in the north of Israel - preliminary results. Israel Journal of Zoology 39: 47. Close ), while another study in Israel reported that birds fed approximately every three days (281 Spiegel, O., R. Harel, W. M. Getz, and R. Nathan (2013). Mixed strategies of griffon vultures’ (Gyps fulvus) response to food deprivation lead to a hump-shaped movement pattern. Movement Ecology 1: 5. Close ). In the Eastern Rhodopes (Bulgaria and Greece), it attended feeding events every 1.6 d on average, decreasing the number of visits to every 4.1 d in January and February (282 Arkumarev, V., D. Dobrev, A. Stamenov, N. Terziev, A. Delchev, and S. Stoychev (2021). Seasonal dynamics in the exploitation of natural carcasses and supplementary feeding stations by a top avian scavenger. Journal of Ornithology Close ). The food deprivation period in the wild can be longer; in a tracked Eurasian Griffon breeding pair, the male underwent a continuous incubation period of 31 d after loss of the female. Tracking data showed that the vulture survived this starvation event (300 Arkumarev, V. S., E. J. Kret, A. A. Stamenov, T. A. Skartsi, and D. D. Dobrev (2021). The longest food deprivation period of a Griffon Vulture (Gyps fulvus) recorded in the wild and exceptionally long nest attendance. Ecologia Balkanica 13(2):239–244. Close ). In a nest in southern Spain, the male was shot dead on the day 30 of incubation; from that day, the female incubated for 28 uninterrupted days until the chick hatched. Two days later, the chick was found dead and the female was observed flying from the nest (301 Fernández, J. A. (1977). Comportamiento del buitre leonado (Gyps f. fulvus) en nido. Ardeola 22: 29–54. Close ).

The Eurasian Griffon is also most active when hungry; it flies greater distances and moves farther from the roost when hungry than when it is satiated. To avoid starvation, it will change its foraging strategy based on how many days it has gone without food. For the first few days without food, it will travel farther, increase its maximal displacement (Euclidean distance between the initial and farthest location of the day), and fly at a higher altitudes to increase its chances of finding food. In the days that follow, these three measures decrease, indicating the adoption of a strategy that minimizes energy expenditure. Spiegel et al. (281 Spiegel, O., R. Harel, W. M. Getz, and R. Nathan (2013). Mixed strategies of griffon vultures’ (Gyps fulvus) response to food deprivation lead to a hump-shaped movement pattern. Movement Ecology 1: 5. Close ) found that birds usually made one or two stops per day, rarely more than four, before returning to the evening roost. In Bizkaia (Spain), 24 experimental feeding sites were established in an area of ​​10,614 km² to analyze the foraging movements of banded Eurasian Griffon (n = 241). Rather than moving randomly throughout the entire study area, adults congregated at three separate core feeding areas; subadults exhibited the same behavior, once they had become established in the breeding colony. The study suggested that this species restricts its foraging to areas close to its breeding site (302 Zuberogoitia, I., J. A. González-Oreja, J. E. Martínez, J. Zabala, I. Gómez, and P. López-López (2013). Foraging movements of Eurasian griffon vultures (Gyps fulvus): implications for supplementary feeding management. European Journal of Wildlife Research 59(3): 421–429. Close ).

The highest number of individuals observed near carrion was 146 in the Pyrenees Mountains (France; 200 Carlon, J., and J. L. Dunoguiez (1990). Observations éco-éthologiques sur une reproduction record en altitude du Vautour fauve Gyps fulvus dans le Paléarctique Occidental, sur le versant nord des Pyrénées. L’Oiseau et la Revue Francaise d'Ornithologie 60(3): 243–248. Close ), and more than 300 in Spain (272 Donázar, J. A. (1993). Los Buitres Ibéricos: Biología y Conservación. J. M. Reyero, Madrid, Spain. Close ). Congregations of ca. 1,000 birds were observed at feeding sites in Segovia (Spain; 303 Acha, A., G. Blanco, P. Ruiz, F. Martínez, and G. Doval (1998). A great banquet at a spanish vulture restaurant. Does Europe end at the Pyrenees? Vulture News 39: 34–39. Close ). In a feeding group, an individual gains access to carrion based on its age, fighting ability, and hunger level (304 Bosè, M., O. Duriez, and F. Sarrazin (2012). Intra-specific competition in foraging Griffon Vultures Gyps fulvus: 1. Dynamics of group feeding. Bird Study 59(2): 182–192. Close , 296 Harel, R., O. Spiegel, W. M. Getz, and R. Nathan (2017). Social foraging and individual consistency in following behaviour: testing the information centre hypothesis in free-ranging vultures. Proceedings of the Royal Society B: Biological Sciences 284: 20162654. Close , 305 Moreno-Opo, R., A. Trujillano, and A. Margalida (2020). Larger size and older age confer competitive advantage: dominance hierarchy within European vulture guild. Scientific Reports 10:2430. Close ). A field study in southern Israel with tracked birds found that the time to initiate feeding was negatively associated with age and with hunger level, and positively associated with arrival time (n = 62; 296 Harel, R., O. Spiegel, W. M. Getz, and R. Nathan (2017). Social foraging and individual consistency in following behaviour: testing the information centre hypothesis in free-ranging vultures. Proceedings of the Royal Society B: Biological Sciences 284: 20162654. Close ). In France, older adults arrived at carcasses first and departed before other age-classes arrived. The mean duration of stay at carcasses was 5.2 min ± 12.7 SD in old adults, 13.9 min ± 15.5 SD in young adults, and 29.5 min ± 44.8 SD in immatures (304 Bosè, M., O. Duriez, and F. Sarrazin (2012). Intra-specific competition in foraging Griffon Vultures Gyps fulvus: 1. Dynamics of group feeding. Bird Study 59(2): 182–192. Close ). In Spain, adults remained at carcasses for a mean of 17.6 min ± 3.7 SD (n = 72), and non-adults for 26.7 min ± 4.0 SD (n = 128), feeding for 6.3 min ± 1.2 SD and 9.5 min ± 1.4 SD, respectively (288 Moreno-Opo, R., A. Trujillano, and A. Margalida (2016). Behavioral coexistence and feeding efficiency drive niche partitioning in European avian scavengers. Behavioural Ecology 27:1047–1059. Close ).

Occasionally, birds will spend the night on trees or rocks next to the carcass to continue feeding the next day, as observed in Spain (293 König, C. (1974). Zum verhalten spanischer Geier an Kadavern. Journal für Ornithologie 115(3):289–320. Close ) and India (215 Grubh, R. B. (1978). The Griffon vultures (Gyps bengalensis, G. indicus & G. fulvus) of Gir Forest: their feeding habits and the nature of association with the asiatic lion. The Journal of the Bombay Natural History Society 75: 1058–1068. Close ). At Gir National Park (India), when a carcass was in the open, some vultures continued feeding during moonlit nights (215 Grubh, R. B. (1978). The Griffon vultures (Gyps bengalensis, G. indicus & G. fulvus) of Gir Forest: their feeding habits and the nature of association with the asiatic lion. The Journal of the Bombay Natural History Society 75: 1058–1068. Close ). In alpine pastures of Somiedo Natural Park (Asturias Region, Spain), at least 14 Eurasian Griffon were recorded by camera traps scavenging a mean of three hours per night at two cow carcasses during five nights in summer. The minimum number of Eurasian Griffon scavenging during the night (mean 4 ± 1 SE) was lower that during the day (mean 8 ± 1 SE). Nocturnal mean temperatures were higher (13.9°C ± 0.6° SE) during scavenging nights than during other nights (8.1°C ± 0.6 SE; 306 Mateo-Tomás, P., and P. P. Olea (2018). Griffon vultures scavenging at night: trophic niche expansion to reduce intraspecific competition? Ecology 99(8):1897–1899. Close ). In Bulgaria, 19 cases of nocturnal activity on the ground by 1–3 individuals were recorded at Kresna Gorge during 2012–2022. Active feeding was observed in 68.4% of cases (307 Peshev, H., E. Mitrevichin, A. Grozdanov, and E. Stoynov (2022). Nocturnal activity of Griffon Vultures at a feeding site in Kresna Gorge, Bulgaria. Vulture News 82:23–28. Close ). In the central Apennines (Italy), nocturnal and crepuscular feeding on a horse carcass was observed (308 Damiani, G., and M. Posillico (2024). Nocturnal feeding in the Eurasian Griffon Vulture Gyps fulvus: a response to human disturbance and the presence of mammalian predators. Ardeola 71(2):325–334. Close ).

In France, more old adults than young adults and immatures were observed at carrion sites, although in autumn the number of juveniles at a carrion site increased (304 Bosè, M., O. Duriez, and F. Sarrazin (2012). Intra-specific competition in foraging Griffon Vultures Gyps fulvus: 1. Dynamics of group feeding. Bird Study 59(2): 182–192. Close ). Juvenile vultures preferred to feed at supplementary feeding points located far from the breeding colonies and where less and more irregular carrion is deposited. Juveniles arrived at these sites before adults and in a higher proportion (309 Duriez, O., S. Herman, and F. Sarrazin (2012). Intra-specific competition in foraging Griffon Vultures Gyps fulvus: 2. The influence of supplementary feeding management. Bird Study 59(2): 93–206. Close ). As the group size increased, the feeding rate decreased due to competition and interference (310 Bosè, M., and F. Sarrazin (2007). Competitive behaviour and feeding rate in a reintroduced population of Griffon Vultures, Gyps fulvus. Ibis 149: 490–501. Close ). During carrion exploitation observations in Spain, birds followed a dominance gradient from adults to subadults and juveniles, fought to keep positions close to the carrion, and defended pieces of food from theft by other vultures (305 Moreno-Opo, R., A. Trujillano, and A. Margalida (2020). Larger size and older age confer competitive advantage: dominance hierarchy within European vulture guild. Scientific Reports 10:2430. Close ).

Major Food Items

In Spain, the Eurasian Griffon feeds on goat, sheep , donkey, cow , Iberian ibex (Capra pyrenaica), Pyrenean chamois (Rupicapra pyrenaica), red deer (Cervus elaphus), horse, domestic pig, wild boar (Sus scrofa), dog, cat, European fallow deer (Dama dama), red fox (Vulpes vulpes), Iberian hare (Lepus granatensis), European rabbit (Oryctolagus cuniculus), and birds (311 Fernández, J. A. (1975). Consideraciones sobre el régimen alimenticio de Gyps fulvus. Ardeola 21: 209–217. Close , 301 Fernández, J. A. (1977). Comportamiento del buitre leonado (Gyps f. fulvus) en nido. Ardeola 22: 29–54. Close , 312 Hiraldo, F. (1977). Relaciones entre morfología, ecología y distribución de los buitres del Viejo Mundo. In Actas I Reunión Iberoamericana de Zoología de Vertebrados, La Rábida, Spain. pp. 753–757. Close , 313 Marco, J., and D. García (1981). Situation actuelle des populations de necrophagues (Gyps fulvus, Gypaetus barbatus, et Neophron percnopterus) en Catalogne. In Rapaces Mediterranéens (G. Cheylan and J. C. Thibault, Editors). Annales du Centre de Recherche Ornithologique de Provence, 1, Aix-en-Provence, France. pp. 66–69. Close , 314 González, L. M., J. L. González, and C. Llandres (1984). Tree-nesting colony of griffon vultures in Spain. Vulture News 11: 12–13. Close , 17 Elosegi, I. (1989). Vautour fauve (Gyps fulvus), Gypaete barbu (Gypaetus barbatus), percnoptere d’Egypte (Neophron percnopterus): Synthèse bibliographique et recherches. Acta Biologica Montana, Série documents de travail 3: 1–278. Close , 272 Donázar, J. A. (1993). Los Buitres Ibéricos: Biología y Conservación. J. M. Reyero, Madrid, Spain. Close , 315 Margalida, A. (1997). Consumición de pequeños cadáveres por parte de buitres leonados Gyps fulvus en Cataluña (NE España). Butlletí del Grup Català d'Anellament 14: 55–57. Close ). In Germany, feeding at carcasses of cow, pig, and sheep was recorded (148 Krüger, T., and J. A. Krüger (2007). Einflug von Gänsegeiern Gyps fulvus in Deutschland 2006: Vorkommen, mögliche Ursachen und naturschutzfachliche Konsequenzen. Limicola 21(3): 185–217. Close ). In Crete (Greece), meals of sheep, goat, rabbit, and beech marten (Martes foina) were recorded (316 Xirouchakis, S. M. (2005). The diet of Eurasian Griffons (Gyps fulvus) in Crete. Journal of Raptor Research 39(2): 179–183. Close ).

In Armenia, food items include horse, wild goat (Capra aegagrus), and brown bear (Ursus arctos; 317 Adamian, M. S., and D. Klem (1999). Handbook of the Birds of Armenia. American University of Armenia, Yerevan, Armenia. Close ). In Azerbaijan, it feeds on cattle, domestic buffalo, horse, donkey, sheep, goat, dog, cat, red deer, urial (Ovis orientalis), Daghestan tur (Capra cylindricornis), chamois (Rupicapra rupicapra), wild goat, goitered gazelle (Gazella subgutturosa), European roe (Capreolus capreolus), wild boar, saiga antelope (Saiga tatarica), brown bear, gray wolf (Canis lupus), golden jackal (Canis aureus), red fox, European badger (Meles meles), raccoon (Procyon lotor), marbled polecat (Vormela peregusna), beech marten (Martes foina), least weasel (Mustela nivalis), European hare (Lepus europaeus), Indian porcupine (Hystrix indica), spur-thighed tortoise (Testudo graeca), grass snake (Natrix natrix), European glass lizard (Pseudopus apodus), and fish (318 Karimov, T., and G. Guliyev (2017). Diet composition of four vulture species in Azerbaijan. Ardea 105(2):163–168. Close , 319 Rajabova, S., and T. Karimov (2021). The composition and dynamics of the diet of the Black Vulture (Aegypius monachus) and Griffon Vulture (Gyps fulvus) in the Talysh region of Azerbaijan. Journal of V. N. Karazin Kharkiv National University, Series Biology 37:65–69. Close ). In Kazakhstan, it has been documented feeding on domestic livestock, Siberian roe deer (Capreolus pygargus; 320 Batryakov, R. R. (2020). O vstreche belogolovogo sipa Gyps fulvus v Naurzume v 2020 godu. Russkiy Ornitologicheskiy Zhurnal 29, Ekspress-vypusk 1982: 4677–4678. Close ), Siberian ibex (Capra sibirica), argali (Ovis ammon), goitered gazelle, saiga antelope, and steppe marmot (Marmota bobak; 115 Korelov, M. N. (1962). Otryad khishchnyye ptitsy – Falconiformes. In Ptitsy Kazakhstana (V. F. Gavrin, I. A. Dolgushin, M. N. Korelov, and M. A. Kuzmina, Editors). Tom 2. Izdatel'stvo Akademii Nauk Kazakhskoy SSR, Alma-Ata. pp. 488–707. Close ). In Turkmenistan, wild goat, urial (Ovis orientalis), Russian tortoise (Testudo horsfieldii), red fox, cow, sheep, horse, camel and donkey were recorded as part of its diet (321 Efimenko, H. H. (2019). Belogolovyy sip Gyps fulvus – ischezayushchiy vid Tsentral'nogo Kopetdaga (Turkmenistan). Russkiy Ornitologicheskiy Zhurnal 28, Ekspress-vypusk 1723: 360–363. Close ). In Cyprus, a Eurasian Griffon fed on a rat (Rattus rattus; 322 Spitzenberger, F. (1978). Die Säugetierfauna Cyperns. Teil I: Insectivora und Rodentia. Annales Naturhistorisches Museum Wien 81: 401–441. Close ). In Gir National Park (India), it consumed water buffalo, zebu cattle, camel, horse, chital (Axis axis), nilgai (Boselaphus tragocamelus), sambar (Rusa unicolor), and Indian porcupine (215 Grubh, R. B. (1978). The Griffon vultures (Gyps bengalensis, G. indicus & G. fulvus) of Gir Forest: their feeding habits and the nature of association with the asiatic lion. The Journal of the Bombay Natural History Society 75: 1058–1068. Close ). In Little Rann of Kachchh (Gujarat, India), a bird was observed feeding on a carcass of wild ass (Equus hemionus; 323 Desai, B. R. (2015). Eurasian Griffon Vulture scavenging on Wild Ass in Little Rann of Kachchh. Flamingo 13(4):21. Close ). Eurasian Griffon wintering in Gambia were observed feeding at carcasses of donkey, cow, goat, and horse (133 Roy, K. (2005). Sightings of European Griffon Vultures in eastern Gambia from December 1999 to January 2005. Vulture News 53: 20–23. Close ). It was also recorded feeding on dead camels (Camelus dromedarius) once near Gebel Abu Hareigal (Egypt; 173 Goodman, S. M., and P. L. Meininger, Editors (1989). The Birds of Egypt. Oxford University Press, Oxford, UK. Close ).

Eurasian Griffon were recorded feeding on Mallard (Anas platyrhynchos) carcasses in Hungary (324 Beretzk, P. (1950). The avifauna of the Fehértó near the town Szeged. Aquila 51-54: 51–80. Close ), and Graylag Goose (Anser anser) carcasses in Doñana National Park (Spain; 325 Hiraldo, F., J. C. Blanco, and J. Bustamante (1991). Unspecialized exploitation of small carcasses by birds. Bird Study 38(3):200–207. Close ). It also occasionally feeds on road-killed animals, such as cats (315 Margalida, A. (1997). Consumición de pequeños cadáveres por parte de buitres leonados Gyps fulvus en Cataluña (NE España). Butlletí del Grup Català d'Anellament 14: 55–57. Close ) and dogs (326 PMVC (2003). Mortalidad de vertebrados en carreteras. Documento técnico de conservación no 4. Sociedad para la Conservación de los Vertebrados (SCV), Madrid, Spain. Close ). The ingestion of European mudminnow (Umbra krameri), 5–10 cm in length, thrown away by fishermen, was recorded at the mouth of the Dniester river (Ukraine; 9 Glutz von Blotzheim, N., K. M. Bauer, and E. Bezzel (1971). Handbuch der Vögel Mitteleuropas. Band 4. Falconiformes. Akademische Verlagsgesellschaft, Frankfurt am Main, Germany. Close ). The Eurasian Griffon also occasionally feeds on individuals of its own species. There is a record of birds feeding on a dead conspecific (327 Camiña, A., R. Palomo, and J. C. Torres (2002). Observation of cannibalism in Eurasian griffons Gyps fulvus in Spain. Vulture News 47: 25–26. Close ); in another instance, a Eurasian Griffon whose wing had been trapped by a falling rock was killed and consumed by other individuals (328 Martínez de Lecea, F., A. Hernando, A. Illana, and J. Echegaray (2011). Cannibalism in Eurasian Griffon Vultures Gyps fulvus. Ardea 99(2): 240–242. Close ).

The Eurasian Griffon rarely carries food away from the feeding site. However, in Abkhazia (Georgia) in June, an adult was observed arriving at the nest carrying intestine, probably sheep, in its claws (329 Fischer, W. (1975). Nahrungstransport des Gänsegeiers (Gyps fulvus) mit den Fängen und einige Bemerkungen zum Bartgeier (Gypaetus barbatus). Beiträge zur Vogelkunde 21(6): 497–500. Close ). It was also observed in May flying in Cyprus with a rat in its beak (322 Spitzenberger, F. (1978). Die Säugetierfauna Cyperns. Teil I: Insectivora und Rodentia. Annales Naturhistorisches Museum Wien 81: 401–441. Close ).

There is evidence that this species benefits from the hunting of wild ungulates, particularly red deer and wild boar. A study conducted in the Cantabrian Mountains (Spain) revealed that the location of roosts within the study area overlapped with hunting sectors containing the highest number of shot red deer and wild boar. Additionally, the birds occupied these roosts during months that coincided with the hunting season (330 Mateo-Tomás, P., and P. P. Olea (2010). When hunting benefits raptors: a case study of game species and vultures. European Journal of Wildlife Research 56(4): 519–528. Close ). Since 2000, however, European Union legislation has progressively limited the abandonment of dead animals. As a result, the Eurasian Griffon has expanded its trophic niche to include significant numbers of rabbits and garbage (331 Donázar, J. A., A. Cortés-Avizanda, and M. Carrete (2010). Dietary shifts in two vultures after the demise of supplementary feeding stations: consequences of the EU sanitary legislation. European Journal of Wildlife Research 56(4): 613–621. Close ).

Although the Eurasian Griffon is considered an obligate scavenger, it is nonetheless capable of eating very weak animals that are still alive, though it does this rarely (272 Donázar, J. A. (1993). Los Buitres Ibéricos: Biología y Conservación. J. M. Reyero, Madrid, Spain. Close ). For example, Camiña Cardenal et al. (332 Camiña Cardenal, A., A. Honrubia Baticón, and A. Senosiain (1995). Attacks on livestock by Eurasian griffons in northern Spain. Journal of Raptor Research 29(3): 214. Close ) observed birds devouring a very weakened, yet live, sheep. In areas of high population density in northern Spain, it also occasionally preys on newborn cattle (see also Conservation and Management). It has also been documented predating White Stork (Ciconia ciconia) nestlings in the Netherlands (276 Koopman, F. (2004). Vale Gieren Gyps fulvus versus Ooieveaars Ciconia ciconia. Het Vogeljaar 52(1): 3–8. Close ).

While vertebrate carcasses comprise the dominant food items for the species, other items may also be consumed. For example, in Andalucía (Spain), a nestling vomited three small snails (301 Fernández, J. A. (1977). Comportamiento del buitre leonado (Gyps f. fulvus) en nido. Ardeola 22: 29–54. Close ). There also is a record of birds eating beetles in Andalucía (333 Beven, G. (1979). Griffon vulture apparently feeding on beetles. British Birds 72(7): 336. Close ; see Quantitative Analysis). In Romania, snails and large insects were found in their crop (179 Von Dombrowski, R. R. (1910). Ornis Romaniae; die Vogelwelt Rumänien’s systematisch und biologisch-geographisch beschrieben (Forsetzung). Buletinul Societății de Șciințe din București-România 19(1/2):1272–1463. Close ). One source also mentions it feeding on dry grass (9 Glutz von Blotzheim, N., K. M. Bauer, and E. Bezzel (1971). Handbuch der Vögel Mitteleuropas. Band 4. Falconiformes. Akademische Verlagsgesellschaft, Frankfurt am Main, Germany. Close ). Pellets of long grass, fibers, and green leaves of the cork tree were found in Cádiz (Spain) near nests and roosts (206 Irby, L. H. (1895). The Ornithology of the Straits of Gibraltar. Second Edition. Taylor & Francis, London, UK. Close ); it has been observed eating plants in other situations as well (334 Fernández, F. J. (1998). Buitres leonados (Gyps fulvus) comiendo plantas. El Escribano 17: 2–6. Close ; see also Quantitative Analysis). It has also been observed ingesting grit (335 Camiña Cardenal, A. (2002). Observations of feeding Eurasian griffons Gyps fulvus in Spain. Vulture News 46: 13–14. Close ); a nestling vomited a piece of grit that was 2.5 cm (301 Fernández, J. A. (1977). Comportamiento del buitre leonado (Gyps f. fulvus) en nido. Ardeola 22: 29–54. Close ), and one individual had some 7 mm diameter grit in its intestine (336 Palaus Soler, F. J. (1960). Notas ornitológicas del nor-este de España (con algunos datos de Levante). Ardeola 6(1): 221–234. Close ). It also often swallow indigestible fragments of glass, plastic, and metal. These fragments were found in or near the nest and in the stomach of chicks in Israel and Armenia (337 Houston, D. C., A. Mee, and M. McGrady (2007). Why do condors and vultures eat junk?: The implications for conservation. Journal of Raptor Research 41:235–238. Close ). Ceramic fragments were found in food regurgitated by nestlings in the Pyrenees (17 Elosegi, I. (1989). Vautour fauve (Gyps fulvus), Gypaete barbu (Gypaetus barbatus), percnoptere d’Egypte (Neophron percnopterus): Synthèse bibliographique et recherches. Acta Biologica Montana, Série documents de travail 3: 1–278. Close ).

Calcium, necessary for eggshell formation and bone mineralization, is scarce in the typical diet of soft tissue (338 Houston, D. C. (1978). The effect of food quality on breeding strategy in Griffon Vultures (Gyps spp). Journal of Zoology 186(2): 175–184. Close ). To compensate for this scarcity in its typical diet, it has been recorded to consuming bone fragments both in captivity and in the wild at Gir National Park (India; 339 Grubh, R. B. (1973). Calcium intake in vultures of the genus Gyps. Journal of the Bombay Natural History Society 70: 199–200. Close ) and in Spain (293 König, C. (1974). Zum verhalten spanischer Geier an Kadavern. Journal für Ornithologie 115(3):289–320. Close ; see also Quantitative Analysis and Social and Interspecific Behavior).

Quantitative Analysis

In Andalucia (Spain), the Eurasian Griffon feeds mainly on goat (34.9%), sheep (20.9%), donkey (11.6%), and cow (7%). To a lesser extent, it also feeds on red deer, horse, and dogs. Birds were also observed occasionally feeding on fallow deer, dromedary camel, fox, and hare (311 Fernández, J. A. (1975). Consideraciones sobre el régimen alimenticio de Gyps fulvus. Ardeola 21: 209–217. Close ). In the Sierra Morena mountains (southern Spain), goat and sheep dominated the diet (43.3%), followed by red deer (21.6%), horses (7.5%), cattle (6%), domestic pig (5.2%), and birds (5.2%; 312 Hiraldo, F. (1977). Relaciones entre morfología, ecología y distribución de los buitres del Viejo Mundo. In Actas I Reunión Iberoamericana de Zoología de Vertebrados, La Rábida, Spain. pp. 753–757. Close ). Samples of food regurgitated (n = 151) by nestlings (n = 91) in the Pyrenees (Spain) were composed of muscle tissue (43.05%), plants (17.25%), viscera (10%), bones (9.95%), skin (2.65%), cartilage (2%), tendons (1.3%), and snails (1.3%; 17 Elosegi, I. (1989). Vautour fauve (Gyps fulvus), Gypaete barbu (Gypaetus barbatus), percnoptere d’Egypte (Neophron percnopterus): Synthèse bibliographique et recherches. Acta Biologica Montana, Série documents de travail 3: 1–278. Close ). In Crete (Greece), sheep hair was present in 89.45% of regurgitated pellets, goat hair in 15.5%, rabbit hair in 2.8%, and beech marten hair in 1.4% (n = 142 pellets; 316 Xirouchakis, S. M. (2005). The diet of Eurasian Griffons (Gyps fulvus) in Crete. Journal of Raptor Research 39(2): 179–183. Close ). In the Eastern Rhodopes (Bulgaria and Greece), the diet was composed mainly of domestic animals (86.9%), including cattle (48.5%), sheep (24.3%), goat (6.6%), horse (3.6%), donkey (2.3%), and dog (1.6%). Wild food items included fallow deer (8.5%), European roe deer (2.3%), red deer (0.7%), wild boar (0.7%), European hare (0.3%), red fox (0.3%), and golden jackal (0.3%, n = 265; 274 Arkumarev, V., D. Dobrev, A. Stamenov, N. Terziev, A. Delchev, and S. Stoychev (2020). Using GPS and accelerometry data to study the diet of a top avian scavenger. Bird Study 67(3): 300–310. Close ).

In Turkmenistan, from 1980–2007, records showed a diet of urial (Ovis orientalis, 27.9%), wild goat (Capra aegagrus, 27.1%), sheep (12.9%), Russian tortoise (Testudo horsfieldii, 10.7%), cow (7.1%), goitered gazelle (Gazella subgutturosa, 3.6%), camel (3.6%), onager (Equus hemionus, 2.9%), horse (2.8%), donkey (0.7%), and red fox (0.7%, n = 140; 340 Efimenko N. N. (2008). Griffon Vulture within Turkmenistan. Strepet 6(1): 93–106. Close ). In the central Kopet Dag Mountains (Turkmenistan), wild animals (75.7%) prevailed over domestic cattle (24.3%). Wild goat (32.45%) and urial (32.45%) were the most important items in the diet, while Russian tortoise (9.9%) and red fox (0.9%) were represented in small amounts. Domestic ungulates such as cow (9.0%), sheep (9.0%), horse (3.6%), camel (1.8%), and donkey (0.9%) had lower representation in its diet (n = 111; 321 Efimenko, H. H. (2019). Belogolovyy sip Gyps fulvus – ischezayushchiy vid Tsentral'nogo Kopetdaga (Turkmenistan). Russkiy Ornitologicheskiy Zhurnal 28, Ekspress-vypusk 1723: 360–363. Close ). In Gir National Park (India), domestic livestock represented 92.2% of carcasses recorded and wild animals only 7.2% (n = 194; 218 Grubh, R. B. (1978). Competition and co-existence in Griffon vultures: Gyps bengalensis, G. indicus and G. fulvus in Gir Forest. Journal of Bombay Natural History Society 75(3): 810–814. Close ). Domestic livestock included water buffalo (56.70%), zebu cattle (31.95%), camel (3.09%), and horse (1.03%); wild animals were represented by chital (2.57%), nilgai (2.57%), sambar (1.54%), and Indian porcupine (0.51%, n = 194; 215 Grubh, R. B. (1978). The Griffon vultures (Gyps bengalensis, G. indicus & G. fulvus) of Gir Forest: their feeding habits and the nature of association with the asiatic lion. The Journal of the Bombay Natural History Society 75: 1058–1068. Close ).

In Azerbaijan, the diet showed variation across years that correlated with food availability. In 2008–2009, a large number of sheep were killed by predators, which was reflected by the fact that 60.5% of food items found in nests during that period were sheep (n = 261). The following year (2010), a large number of predators were killed by farmers and pet owners and, consequently, gray wolf (30.8%), golden jackal (27.7%), and red fox (20.0%) represented a higher proportion of food items in the diet of Eurasian Griffon (n = 65). In 2011–2012, the carcasses of 192 horses left illegally became a dominant food source, representing 73.3% of food items (n = 150; 318 Karimov, T., and G. Guliyev (2017). Diet composition of four vulture species in Azerbaijan. Ardea 105(2):163–168. Close ). In the years 2014–2016, red fox (22–23% of prey items) and golden jackal (19–21% of prey items) were the most important prey of Eurasian Griffon in Azerbaijan (319 Rajabova, S., and T. Karimov (2021). The composition and dynamics of the diet of the Black Vulture (Aegypius monachus) and Griffon Vulture (Gyps fulvus) in the Talysh region of Azerbaijan. Journal of V. N. Karazin Kharkiv National University, Series Biology 37:65–69. Close ).

In Spain, individual Eurasian Griffon were observed feeding most frequently on muscle tissue and viscera of carrion (284 Alvarez, F., L. Arias de Reyna, and F. Hiraldo (1976). Interactions among avian scavengers in southern Spain. Ornis Scandinavica 7:215–226. Close , 288 Moreno-Opo, R., A. Trujillano, and A. Margalida (2016). Behavioral coexistence and feeding efficiency drive niche partitioning in European avian scavengers. Behavioural Ecology 27:1047–1059. Close , 17 Elosegi, I. (1989). Vautour fauve (Gyps fulvus), Gypaete barbu (Gypaetus barbatus), percnoptere d’Egypte (Neophron percnopterus): Synthèse bibliographique et recherches. Acta Biologica Montana, Série documents de travail 3: 1–278. Close ). Another study in Spain observed birds feeding mostly on organs and fleshy parts (nearly 78% of observations), and to a lesser extent on coarse muscle flesh, sinews, and pieces of skin (20% of observations, n = 321; 286 König, C. (1983). Interspecific and intraspecific competition for food among Old World vultures. In Vulture Biology and Management (S. R. Wilbur and J. A. Jackson, Editors), University of California Press, Berkeley, CA, USA. pp. 153–171. Close ). See Diet: Quantitative Analysis.

In GPS-tracked individuals from a population in northern Spain, feeding was based on human-derived resources, whereas in GPS-tracked individuals from a southern population, feeding was based on wild ungulates. In a western Iberian foraging area shared by both populations, in which there are both wild and human-derived resources, individuals preferentially used resources similar to those of their original population, suggesting a cultural component in the diet (341 Arrondo, E., E. Sebastián-González, M. Moleón, M., Z. Morales-Reyes, J. M. Gil-Sánchez, A. Cortés-Avizanda, O. Ceballos, J. A. Donázar, and J. A. Sánchez-Zapata (2023). Vulture culture: dietary specialization of an obligate scavenger. Proceedings of the Royal Society B: Biological Sciences 290(1998):20221951. Close ).

Differences in diet between males and females have been observed in Spain. Males consumed more trophic resources of human origin and visited intensive livestock farms and carcass-dumping sites more, while females more frequently visited hunting properties (341 Arrondo, E., E. Sebastián-González, M. Moleón, M., Z. Morales-Reyes, J. M. Gil-Sánchez, A. Cortés-Avizanda, O. Ceballos, J. A. Donázar, and J. A. Sánchez-Zapata (2023). Vulture culture: dietary specialization of an obligate scavenger. Proceedings of the Royal Society B: Biological Sciences 290(1998):20221951. Close ).

Information needed.

In one study, the resting body temperature had a mean value of 37.7 ºC during the night and 38.9 ºC during the day. Body temperature increased significantly as air temperature increased, whereas metabolic rate did not vary significantly; variation in body temperature independent of metabolic rate may function as a mechanism for saving energy (n = 14; 342 Prinzinger, R., B. Nagel, O. Bahat, R. Bogel, E. Karl, D. Weihs, and C. Walzer (2002). 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: 456–467. Close ). In response to food deprivation over 10.5 d, captive Eurasian Griffon (n = 6) increased body temperature variation, resulting in 4–6 ºC lower body temperature at night, thereby minimizing nocturnal energy expenditure (343 Bahat, O., I. Choshniak, and D. C. Houston (1998). Nocturnal variation in body temperature of Griffon vultures. The Condor 100: 168–171. Close ).

In warm areas, such as the Mediterranean region, nestlings are unable to protect themselves from direct solar radiation and heat in exposed aeries. Parents, therefore, spend long periods of time shading the chicks to prevent them from overheating (18 Fargallo, J. A., F. Martínez, K. Wakamatsu, D. Serrano, and G. Blanco (2018). Sex-Dependent Expression and Fitness Consequences of Sunlight-Derived Color Phenotypes. The American Naturalist 191(6): 726–743. Close , 344 Xirouchakis, S. M., and M. Mylonas (2007). Breeding behaviour and parental care in the Griffon vulture Gyps fulvus on the island of Crete (Greece). Ethology Ecology & Evolution 19(1): 1–26. Close ). The paler plumage of chicks is considered a mechanism for thermoregulation in response to high sunlight exposure; the Eurasian Griffon is one of the few endotherm species in which this type of acclimating mechanism has been described (18 Fargallo, J. A., F. Martínez, K. Wakamatsu, D. Serrano, and G. Blanco (2018). Sex-Dependent Expression and Fitness Consequences of Sunlight-Derived Color Phenotypes. The American Naturalist 191(6): 726–743. Close ).

The Eurasian Griffon gathers at temporary pools to drink (17 Elosegi, I. (1989). Vautour fauve (Gyps fulvus), Gypaete barbu (Gypaetus barbatus), percnoptere d’Egypte (Neophron percnopterus): Synthèse bibliographique et recherches. Acta Biologica Montana, Série documents de travail 3: 1–278. Close ). In the Eastern Rhodopes (Bulgaria and Greece), it used fountains and natural springs for drinking water throughout the year, more often during spring and summer (274 Arkumarev, V., D. Dobrev, A. Stamenov, N. Terziev, A. Delchev, and S. Stoychev (2020). Using GPS and accelerometry data to study the diet of a top avian scavenger. Bird Study 67(3): 300–310. Close ).