Behavior

The Eurasian Griffon forages 7–9 hours each day. Flight types include thermal soaring, linear soaring, slope soaring, gliding, and spiral gliding. Feeding birds exhibit agonistic behavior toward other individuals to maintain their position at a carcass. It is typically monogamous, but extra-pair copulations have been recorded. A colonial and social species, it congregates to breed and to roost, although some pairs reproduce alone, and will also sometimes occupy aeries built by other species. Territorial at nesting sites, it can behave aggressively towards conspecifics. Courtship flights occur near the colony cliffs.

Walking, Running, Hopping, Climbing, etc.

Information needed.

Flight

Three types of soaring (thermal soaring, linear soaring, and slope soaring) and two types of gliding (gliding and spiral gliding) were identified in the Eurasian Griffon using high-resolution tracking data from Spain (349 Khosravifard, S., V. Venus, A. K. Skidmore, W. Bouten, A. R. Muñoz, and A. G. Toxopeus (2018). Identification of Griffon Vulture's Flight Types Using High-Resolution Tracking Data. International Journal of Environmental Research 12(3): 313–325. Close ). To initiate thermal soaring, it enters thermals and circles inside to gain altitude. Initially, thermals are weak and narrow, and the Eurasian Griffon adopts high bank angles (25–35°), during which a bird is inclined about its longitudinal axis with respect to the horizontal, to maximize climb rates. A bird decreases their bank angle and increases their turning radius with altitude (350 Spaar, R. (1997). Flight strategies of migrating raptors; a comparative study of interspecific variation in flight characteristics. Ibis 139: 523–535. Close , 351 Williams, H. J., O. Duriez, M. D. Holton, G. Dell’Omo, R. P. Wilson, and E. L. C. Shepard (2018). Vultures respond to challenges of near-ground thermal soaring by varying bank angle. Journal of Experimental Biology 221:jeb174995. Close ). During linear soaring, there is upward straight flight for at least 350 m, while in slope soaring, the Eurasian Griffon flies in parallel to a cliff in a pattern similar to a figure of eight until a thermal is located. During gliding, a Eurasian Griffon flies in a downward straight direction, while in spiral gliding, it uses a spiral pattern to slowly descend to the nest or to the ground (349 Khosravifard, S., V. Venus, A. K. Skidmore, W. Bouten, A. R. Muñoz, and A. G. Toxopeus (2018). Identification of Griffon Vulture's Flight Types Using High-Resolution Tracking Data. International Journal of Environmental Research 12(3): 313–325. Close ). In another study from Crete (Greece), flight was measured as follows (values given as mean ± SD): 0.6 m/s ± 0.38 SD climb rate in thermals, 8 min ± 6.9 SD duration of thermal soaring, 248 m ± 112.3 SD starting height of thermal soaring, 18.8 m/s ± 9.26 SD inter-thermal gliding speed, 3.5 min ± 1.7 SD duration of inter-thermal gliding, 14.3 min ± 7.1 SD duration spent thermal soaring plus gliding (termed "cross-country phase"), and a speed of 5.1 m/s ± 4.4 SD during the cross-country phase (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 ). See also Food Capture and Consumption.

In a free-flying individual, the heart rate ranged from less than 20 to almost 200 beats/min (352 Bögel, R., R. Prinzinger, E. Karl, and C. Walzer (2000). A multisensor Telemetry System, for studying Flight Biology and Energetics of Free-flying Griffon Vultures - Gyps fulvus. A case study. In Raptors at Risk. Proceedings of the V World Conference on Birds of Prey and Owls (R. D. Chancellor and B. U. Meyburg, Editors). World Working Group on Birds of Prey and Owls and Hancock House, B C, Canada. pp. 879–883. Close ). In another individual, resting heart rate was 44.6 beats/min ± 3.5 SD, increasing to 222 beats/min ± 43 SD upon flapping at take-off. After 10 min of soaring-gliding flight, its heart rate decreased to 81.1 beats/min ± 19.1 SD. Heart rate increased again to 284.7 beats/min ± 49.9 SD at landing ( 353 Duriez, O., A. Kato, C. Tromp, G. Dell’Omo, A. L. Vyssotski, F. Sarrazin, and Y. Ropert-Coudert (2014). How Cheap Is Soaring Flight in Raptors? A Preliminary Investigation in Freely-Flying Vultures. PLoS ONE 9(1): e84887. Close ).

During home-range foraging, the Eurasian Griffon flaps its wings more and flies lower to the ground than on long-haul flights (flying distances of more than 300 km). Young individuals use thermals less and flap more, and breeding individuals fly lower than non-breeding individuals (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 depends on thermal updrafts for flight. In winter, however, rising air thermals are less frequent. Therefore, it stays longer at its roost, flies fewer hours, and must use active flapping to become airborne. In the summer, thermals are stronger and more frequent, ideal for energy-conserving soaring flight (247 Nathan, R., O. Spiegel, S. Fortmann-Roe, R. Harel, M. Wikelski, and W. M. Getz (2012). Using tri-axial acceleration data to identify behavioral modes of free-ranging animals: general concepts and tools illustrated for griffon vultures. Journal of Experimental Biology 215(6): 986–996. Close ). The location and intensity of thermals vary, and a vulture's ability to use them efficiently depends on its age. In weak thermals with low wind speed, juveniles and experienced adults showed no difference in soar-glide efficiency. However, in intermediate wind conditions, adults (more than 5 years) exhibited faster climb rates than those with little experience (less than 2 months; 354 Harel, R., N. Horvitz, and R. Nathan (2016). Adult vultures outperform juveniles in challenging thermal soaring conditions. Scientific Reports 6: 27865. Close ).

A Eurasian Griffon can use social information for flight decisions. In one study, it was observed that to find the next thermal updraft, high-ranking vultures joined those thermals in which there were a greater number of conspecifics, while low-ranking vultures were more likely to search for thermals by themselves (355 Sassi, Y., B. Nouzières, M. Scacco, Y. Tremblay, O. Duriez, and B. Robira (2024). The use of social information in vulture flight decisions. Proceedings of the Royal Society B 291(2018):20231729. Close ).

Swimming and Diving

A Eurasian Griffon migrating through the Strait of Gibraltar was observed to fall into the sea, and it reached the coast by swimming a distance of 400 m (356 Cortés, J. (2009). A migrant griffon vulture Gyps fulvus swims to Spain. Gibraltar Bird Report 9: 48–49. Close ). In another instance, a fledging fell into the sea near Krk Island (Croatia) and swam 50 m to reach the coast (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 ).

Preening, Head-Scratching, Stretching, Sunbathing, Bathing, Anting, ect.

The Eurasian Griffon spends an average of two hours each day preening its plumage and sunbathing, often with open wings (199 Leconte, M. (1977). Étude de la reproduction de Gyps fulvus dans les Pyrénées occidentales. Université de Bordeaux, Bordeaux, France. Close ). Self-maintenance behavior begins at a young age: on day 25 post-hatch, a nestling in captivity started preening while lying down; from day 36 it preened while sitting and included breast plumage in its routine (16 Thaler, E., S. Maschler, and V. Steinkellner (1986). Vergleichende Studien zur Postembryonalentwicklung dreier Altweltgeier: Bartgeier, Schamtzgeier und Gänsgeier. Annalen des Naturhistorischen Museums in Wien. Serie B für Botanik und Zoologie 88–89B: 361–376. Close ). The sunbathing posture with wings spread was observed in captivity beginning on day 95 (16 Thaler, E., S. Maschler, and V. Steinkellner (1986). Vergleichende Studien zur Postembryonalentwicklung dreier Altweltgeier: Bartgeier, Schamtzgeier und Gänsgeier. Annalen des Naturhistorischen Museums in Wien. Serie B für Botanik und Zoologie 88–89B: 361–376. Close ).

Birds will gather in temporary pools to bathe, exhibiting agonistic behavior within the group (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 Rhodope Mountains (Bulgaria and Greece), it used fountains and natural springs for bathing throughout the year, but mostly 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 ).

Sleeping, Roosting

Communal roosts of over a hundred birds have been found throughout the Iberian Peninsula (272 Donázar, J. A. (1993). Los Buitres Ibéricos: Biología y Conservación. J. M. Reyero, Madrid, Spain. Close ). Roosts were found in rocks and in trees (3 Cramp, S., and K. E. L. Simmons, Editors (1980). Handbook of the Birds of Europe, the Middle East and North Africa: The Birds of the Western Palearctic. Volume II: Hawks to Bustards. Oxford University Press, Oxford, UK. Close ). On the island of Crete (Greece), non-breeding birds and failed breeders gathered in cliff-side roosts during March to June and peak between June and August (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 ).

Daily Time Budget

On Crete (Greece), on average, vultures left the colony 1.57 h after sunrise in winter and 2.58 h after sunrise in summer. Mean foraging time per day was 7.6 h ± 1.1 SD and varied between winter (6.8 h ± 0.37 SD) and summer (8.4 h ± 0.90 SD). Birds returned to their colony ca. 2.3 h before sunset throughout the year (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 the Pyrenees, it foraged 7–8 h/d (58.3–66.6% of the period of average annual sunlight); in winter, it spent 5 h foraging, while in summer daily foraging increased to 9 h (199 Leconte, M. (1977). Étude de la reproduction de Gyps fulvus dans les Pyrénées occidentales. Université de Bordeaux, Bordeaux, France. Close ).

In nonbreeding Eurasian Griffon that were tracked (n = 12) from Pyrenees (France), the summer mean time (UTC) of departure from roost was 0641 h ± 0059 SD, and the mean time (UTC) of arrival at roost was 1656 h ± 0043 SD. The mean number of flight bouts per day was 11.68 ± 6.47 SD. About half (54.1% ± 13.0 SD) of the time budget outside of the roosting areas was spent resting on the ground or on a perch. In breeding Eurasian Griffon that were tracked (n = 12) from the Causses (France), the summer mean time (UTC) of departure from roost was 0724 h ± 0034 SD, and mean time (UTC) of arrival at roost was 1618 h ± 0032 SD. The mean proportion of time that these birds spent on the ground or on a perch was 19.0% ± 7.0 SD. The mean number of flight bouts per day was 5.82 ± 1.21 SD (357 Fluhr, J., S. Benhamou, D. Peyrusque, and O. Duriez (2021). Space use and time budget in two populations of Griffon Vultures in contrasting landscapes. Journal of Raptor Research 55(3):425–437. Close ).

Physical and Communicative Interactions

A feeding Eurasian Griffon maintains its position at a carcass by threatening, fighting with, and expelling others, all while employing various vocal expressions; other individuals stand aside and wait for a dominant bird to leave. After a dominant individual finishes feeding, another individual takes its place. When fighting, an aggressor, with bristled mantle and scapular feathers, pecks or jumps on the rival, pushing it with their legs; it can also attack with wings open and raised, and neck stretched forward. Another aggressive posture is to approach the opponent slowly with the head lowered and neck stretched out, wings spread, and mantle and scapulars feathers ruffled, while lifting a leg with the toes spread (358 Valverde, J. A. (1959). Moyens d’expression et hiérarchie sociale chez le vautour fauve Gyps fulvus (Hablizl). Alauda 27: 1–15. Close , 293 König, C. (1974). Zum verhalten spanischer Geier an Kadavern. Journal für Ornithologie 115(3):289–320. 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 ).

Nesting pairs expel other individuals from the nest surroundings by adopting threat postures: a stretched neck, ruffled scapulars and mantle feathers, hanging wings slightly separated from the body, and pecking (199 Leconte, M. (1977). Étude de la reproduction de Gyps fulvus dans les Pyrénées occidentales. Université de Bordeaux, Bordeaux, France. Close ). In high density colonies, competition for nesting sites can lead to very aggressive fights (359 Blanco, G., J. M. Traverso, J. Marchamalo, and F. Martínez (1997). Interspecific and intraspecific aggression among Griffon and Cinereous Vultures at nesting and foraging sites. Journal of Raptor Research 31(1):77–79. Close ).

Territorial Behavior

The Eurasian Griffon is territorial at nesting sites, showing aggressive behavior towards conspecifics. Mated individuals defend the nest and the area within a ca. 5 m radius surrounding it. Territorial behavior occurs during the breeding period, with two peaks in aggressive behavior observed: one month prior to laying, and three weeks prior to fledging. The first peak in territorial aggressive behavior is related to nest defense, and the second peak is related to nestling protection. Adults from neighboring nests have been observed (n = 2) entering other nests and repeatedly pecking the chick so that it vomits and they can steal the food (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 ). In the Pyrenees, nest intrusions by other Eurasian Griffon during the pre-fertile and fertile periods were observed in 90.9% of the nests (n = 33); 14.4% of the agonistic interactions (n = 15) ended with physical aggression. These visits could be related to stealing nest material, or to extra-pair copulation attempts (360 Bertran, J., F. X. Macià, and A. Margalida (2016). How do colonial Eurasian Griffon Vultures prevent extra-pair mating? PeerJ - Life & Environment 4: e1749. Close ).

Mating System and Operational Sex Ratio

Monogamous species (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 , 3 Cramp, S., and K. E. L. Simmons, Editors (1980). Handbook of the Birds of Europe, the Middle East and North Africa: The Birds of the Western Palearctic. Volume II: Hawks to Bustards. Oxford University Press, Oxford, UK. Close ). The process of mate selection and the traits preferred by males or females are unknown (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 ).

Nestling sex-ratio at three breeding areas in central Spain was non-significantly male-biased and did not significantly vary between years (n = 521; period 1990–2020; 361 Gómez-López, G., F. Martínez, A. Sanz-Aguilar, M. Carrete, and G. Blanco (2022). Nestling sex ratio is unaffected by individual and population traits in the griffon vulture. Current Zoology Close ). In central Spain, males showed higher mortality than females during their first year, which has not been found in later years (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 ); wild-hatched populations in southern France followed the same trend (234 Bosé, M., P. Le Gouar, C. Arthur, J. Lambourdière, J. P. Choisy, S. Henriquet, P. Lecuyer, M. Richard, C. Tessier, and F. Sarrazin (2007). Does sex matter in reintroduction of griffon vultures Gyps fulvus? Oryx 41(4): 503–508. Close ). The higher mortality rate of males in early life might explain the female-biased sex ratio among subadult breeders in natural populations (362 Blanco, G., and F. Martínez (1996). Sex Difference in Breeding Age of Griffon Vultures (Gyps fulvus). The Auk 113(1): 247–248. Close ).

Courtship, Copulation, and Pair Bond

Courtship

Courtship flights near the colony cliffs (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 , 3 Cramp, S., and K. E. L. Simmons, Editors (1980). Handbook of the Birds of Europe, the Middle East and North Africa: The Birds of the Western Palearctic. Volume II: Hawks to Bustards. Oxford University Press, Oxford, UK. Close ) start in September and increase in frequency until maximum intensity in mid-December (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 ). In the most common type of courtship flight, birds fly together, one above the other; in one study, on average four birds ± 2 SD participated (range 2–12, n = 102). In another type, birds fly closely next to each other; in one study, on average two birds (± 1 SD) participated (range 2–4, n = 92). In Crete (Greece), the flight of two birds together was short, and lasted no longer than 20 s; the total time spent in aerial displays was 62 s ± 9 SD (range 9–180 s, n = 209; 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 ). Observations of banded individuals in the Massif Central (France) revealed that tandem flight was initiated by the vulture that positioned itself above the other. Tandem flights were performed mostly by mated partners, with the female in the top position (n = 19; 363 Bouze, M., and C. Bagnolini (1995). Le vol en tandem chez le vautour fauve (Gyps fulvus). Canadian Journal of Zoology 73(11): 2144–2153. Close ).

Another form of courtship takes place at the nest. In a study from Crete, allopreening was mostly initiated by the male and usually preceded copulation; the male and female pecked at each other’s face or head for 114 s ± 45 SD (range 24–390 s, n = 59; 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 average time the male and the female were present on the nest increased significantly from the pre-fertile period (32.57% ± 9.10 SD) to the fertile period (47.67% ± 3.84 SD; 360 Bertran, J., F. X. Macià, and A. Margalida (2016). How do colonial Eurasian Griffon Vultures prevent extra-pair mating? PeerJ - Life & Environment 4: e1749. Close ).

Copulation

Before copulation, the male may move around the female in a horizontal position, lifting the tail with the wings half open (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 ). During copulation, the female adopts a horizontal posture and the male then jumps on the back and extends its neck to rub both sides of the female's neck. Male and female emit groaning sounds (364 Mendelssohn, H., and Y. Leshem (1983). Observations on Reproduction and Growth of Old World Vultures. In Vulture Biology and Management (S. R. Wilbur and J. A. Jackson, Editors), University of California Press, Berkeley. pp. 214–241. Close ).

In Crete, copulations were initiated in October and increased in frequency until the pre-laying period in December. Copulation attempts occurred mainly on the nesting ledge (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 ). In Turkmenistan, copulations were observed between 23 November and 5 April (340 Efimenko N. N. (2008). Griffon Vulture within Turkmenistan. Strepet 6(1): 93–106. Close ). In Croatia, copulations were observed between 13 March and 2 May (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 ), and in the Pyrenees (France) on 31 July (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 ).

Copulation attempts lasted on average 48 s ± 65 SD (range 10–420 s, n = 92; 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 ) or 64.6 s (365 Margalida, A., and J. Bertran (2010). Copulatory behaviour in the colonial Eurasian Griffon Vulture Gyps fulvus. Journal of Ethology 28(1): 179–182. Close ). The mean duration of cloacal contact was 11.7 s ± 8.3 SD (range 2.8–50 s, n = 54; 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 observed number of copulation attempts per pair/day was 0.16 ± 0.34 SD (range = 0–1.19) in Crete; in December, daily attempts per pair reached a maximum rate of 1.19 ± 0.55 SD (range = 0–4; 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 ). Another study in the Pyrenees (Spain) recorded a mean copulation frequency of 1.2 copulation attempts per day (365 Margalida, A., and J. Bertran (2010). Copulatory behaviour in the colonial Eurasian Griffon Vulture Gyps fulvus. Journal of Ethology 28(1): 179–182. Close ).

Pair Bond

The monogamous Eurasian Griffon shows evidence of life-long pair bonding (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 , 3 Cramp, S., and K. E. L. Simmons, Editors (1980). Handbook of the Birds of Europe, the Middle East and North Africa: The Birds of the Western Palearctic. Volume II: Hawks to Bustards. Oxford University Press, Oxford, UK. Close ). In a reintroduced population from the Grand Causses region (France), it exhibited strong mate fidelity, where 95% of the identified pairs in any year remained unchanged the following year, and only 4.6% of pairs divorced (n = 107; 238 Sarrazin, F., C. Bagnolini, J. L. Pinna, and E. Danchin (1996). Breeding biology during establishment of a reintroduced Griffon Vulture Gyps fulvus population. Ibis 138: 315–325. Close ). Another study also found support for long-term pair bonds: in Hoces del Riaza Natural Park, Segovia (Spain), of the 71 tagged individuals followed from hatching to 16 years, only one moved to a different aerie after breeding in its original aerie for five years (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 ).

Extra-Pair Mating Behavior/Paternity

Extra-pair copulation in Crete (Greece) represented 3.3% of failed copulation attempts (n = 92) and 4.2% of successful attempts (n = 71; 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 ). In the Pyrenees (Spain), 3.3% of observed copulations (n = 239) were extra-pair copulations (360 Bertran, J., F. X. Macià, and A. Margalida (2016). How do colonial Eurasian Griffon Vultures prevent extra-pair mating? PeerJ - Life & Environment 4: e1749. Close ). Males attempted extra-pair copulations in territories located 20–200 m from their nests. In seven of the eight cases, the copulation attempts were rejected by the females (360 Bertran, J., F. X. Macià, and A. Margalida (2016). How do colonial Eurasian Griffon Vultures prevent extra-pair mating? PeerJ - Life & Environment 4: e1749. Close ). There was no mate-guarding by the Eurasian Griffon, but the number of copulation attempts within a pair positively correlated with the number of neighbors within 20 m (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 ), which is consistent with sperm competition hypothesis. A parentage analysis of nestlings (n = 40) from two colonies in the French Alps did not find evidence of extra-pair fertilization, despite observations of extra-pair copulations, suggesting that pairs in these populations were genetically monogamous (366 Le Gouar, P., J. Sulawa, S. Henriquet, C. Tessier, and F. Sarrazin (2011). Low evidence for extra- pair fertilizations in two reintroduced populations of Griffon Vulture (Gyps fulvus). Journal of Ornithology 152(2): 359–364. Close ).

Brood Parasitism of Conspecifics

Information needed.

Brood Parasitism by Other Species

Information needed.

Degree of Sociality

The Eurasian Griffon breeds mainly in colonies, but also solitarily; there are no comparative data about the costs and benefits of either reproductive strategy. Colonies are usually small (2–20 pairs), but larger colonies (>100 pairs) can occur at sites with high availability of food and nesting sites. In Türkiye, colonies are typically 2–8 pairs, but a solitary pair and a colony of 15 pairs have also been recorded (210 Kirwan, G. M., K. A. Boyla, P. Castell, B. Demirci, M. Özen, H. Welch, and T. Marlow (2008). The Birds of Turkey - the Distribution, Taxonomy and Breeding of Turkish Birds. Christopher Helm, London, UK. Close ). In Crimea (Ukraine), solitary pairs or colonies of two to 11 pairs have been observed (180 Tsvelykh, A. N., B. A. Appak, M. M. Beskaravainy, S. Yu. Kostin, and M. A. Osipova (2018). Vultures of the Ukrainian Fauna. Frankfurt Zoological Society and Institut zoologii Natsional'noy akademii nauk Ukrainy. Ukrainskogo Fitosotsiologicheskogo Tsentra Nauchnoye izdaniye 188, Kiev. Close ). In the Kopet-Dag Mountains (Turkmenistan), solitary pairs or colonies of three to 12 pairs have been documented (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 Spain, colonies tended to be small during surveys in the 1980s, with isolated pairs and colonies of 2–20 pairs in Cataluña (n = 8 colonies; 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 ) and the Sierra de Hornachuelos Natural Park, Córdoba (n = 8 colonies; 367 Acedo García, F., and J. M. Ruiz Mangas (1987). El Buitre leonado (Gyps fulvus) y el negro (Aegypius monachus) en el parque natural de las Sierra de Hornachuelos. Oxyura. Revista sobre las zonas húmedas 4: 222–232. Close ). The 2018 Spanish census recorded 533 isolated pairs, 1,745 colonies with 2–10 pairs, 618 colonies with 11–30 pairs, 154 colonies with 31–100 pairs, and 27 colonies with 101–730 pairs (368 Del Moral, J. C., and B. Molina, Editors (2018). El buitre leonado en España, población reproductora en 2018 y método de censo. Programas de seguimiento de avifauna de SEO/BirdLife, 50, SEO/BirdLife, Madrid, Spain. Close ). In Sardinia (Italy), mean colony size was 12.9 pairs ± 3.6 SE, (range 2–60, n = 16; 369 Aresu, M., M. G. Pennino, D. De Rosa, A. Rotta, and F. Berlinguer (2021). Modelling the effect of environmental variables on the reproductive success of Griffon Vulture (Gyps fulvus) in Sardinia, Italy. Ibis 164(1):255–266. Close ). In Crete (Greece), small colonies were not permanent, and the mean occupation duration was 5 years. The mean group size of declining colonies was 8 ± 3.67 SD (range = 4–16, n = 9), while mean group size of new colonies was 11 ± 6.29 SD (range = 2–27, n = 13; 370 Xirouchakis, S. M., and M. Mylonas (2005). Status and structure of the griffon vulture (Gyps fulvus) population in Crete. European Journal of Wildlife Research 51: 223–231. Close ). Also in the Nurata Nature Reserve (Uzbekistan) it was observed that the colonies were not permanent (237 Mitropolsky, O. V., E. R. Fotteler, and G. P. Tretyakov (1987). Sokoloobraznyye Falconiformes. In Ptitsy Uzbekistana (A. K. Sagitov and R. N. Meklenburtsev, Editors), Tom 1. Izdatel’stvo ‘Fan’, Tashkent. pp. 123–247. Close ).

When not breeding, the Eurasian Griffon is a very social species even away from colonies, gathering in large groups when feeding, during migration, and when roosting (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 , 3 Cramp, S., and K. E. L. Simmons, Editors (1980). Handbook of the Birds of Europe, the Middle East and North Africa: The Birds of the Western Palearctic. Volume II: Hawks to Bustards. Oxford University Press, Oxford, UK. Close ). Groups have also been observed resting in meadows 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 ). See Habitat and Feeding for more details. Among conspecifics, individuals exhibit a dominance gradient, whereby adults are dominant over subadults, which are in turn dominant over juveniles. Agonistic interactions as part of establishing the dominance gradient near carrion include fights, attacks, displacements, and food theft (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 ).

Individual interactions and social dynamics of a population of Eurasian Griffon were examined during the breeding season in a sample of GPS tracked birds (n = 29) in Israel. No single individual had the highest social rank across all three social situations investigated: co-flight, feeding, and roosting. It was estimated that the number of unique individuals each bird interacted with was best predicted during both flights and when feeding. However, the number of total interactions an individual had (strength of social bond) was best predicted by interactions while feeding or while roosting (371 Sharma, N., N. Anglister, O. Spiegel, and N. Pinter-Wollman (2023). Social situations differ in their contribution to population-level social structure in griffon vultures. Ecology and Evolution 13:e10139. Close ).

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Information needed.

Nonpredatory Interspecific Interactions

Temporal segregation and facilitation seems to contribute to species coexistence in vertebrate scavenger communities. In Somiedo and Las Ubiñas-La Mesa Natural Parks (Asturias Region, Spain), single peaks of activity at carcasses were mostly asynchronous among species; however, daily activity patterns of the Eurasian Griffon closely followed those of the Common Raven (Corvus corax) and Carrion Crow (Corvus corone). These observations suggested that earlier presence of corvids at carcasses could facilitate carcass detectability by vultures; subsequently, the vultures could facilitate the corvids' access to carrion (372 Olea, P. P., N. Iglesias, and P. Mateo-Tomás (2022). Temporal resource partitioning mediates vertebrate coexistence at carcasses: the role of competitive and facilitative interactions. Basic and Applied Ecology 60:63–75. Close ).

When feeding at a carcass, vultures of many species exhibit a dominance gradient from larger species to smaller ones, and generally from adults to subadults and juveniles. In one study carried out in Spain, vulture ranks based on successful interactions at carcasses (percentages in parentheses) were in the following order of species and age class: adult and subadult Cinereous Vulture (Aegypius monachus) (75.4%), adult Eurasian Griffon (70.6%), juvenile Cinereous Vulture (69.5%), juvenile Bearded Vulture (Gypaetus barbatus) (68.4%), juvenile Eurasian Griffon (60.9%), subadult Eurasian Griffon (60.7%), adult Bearded Vulture (55.1%), subadult Bearded Vulture (53.2%), and adult Egyptian Vulture (Neophron percnopterus) (33.3%, n = 1,049 agonistic interactions; 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 ). As part of establishing this dominance gradient, agonistic interactions for access to food are common among these species (373 König, C. (1973). Zum Sozialverhalten von Geiern am Futterplatz in Spanien. Ornithologische Mitteilungen 25:118–120. Close , 293 König, C. (1974). Zum verhalten spanischer Geier an Kadavern. Journal für Ornithologie 115(3):289–320. 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 , 325 Hiraldo, F., J. C. Blanco, and J. Bustamante (1991). Unspecialized exploitation of small carcasses by birds. Bird Study 38(3):200–207. Close ). In one instance, violent physical aggression was recorded in which a Cinereous Vulture caused a serious neck wound to a juvenile Eurasian Griffon (359 Blanco, G., J. M. Traverso, J. Marchamalo, and F. Martínez (1997). Interspecific and intraspecific aggression among Griffon and Cinereous Vultures at nesting and foraging sites. Journal of Raptor Research 31(1):77–79. Close ).

A similar dominance gradient from larger species to smaller ones was also observed at Gir Forest National Park (India), where interactions at carcasses between the Eurasian Griffon, Indian Vulture (Gyps indicus), and White-rumped Vulture (Gyps bengalensis) were examined. The Eurasian Griffon, the largest among these three species, was dominant; White-rumped Vulture was the smallest and subordinate to the other two. The Eurasian Griffon won 67% of aggressions against the Indian Vulture (n = 15) and 84% of aggressions against White-rumped Vulture (n = 7). The Indian Vulture won 52% of aggressions against the White-rumped Vulture (n = 52). TheEurasian Griffon and Indian Vulture also spent a larger portion of time engaging in intraspecific agonistic behavior than the White-rumped Vulture, which allowed the smallest species opportunities to feed. The interval between intraspecific fights was 21 min for the Indian Vulture (n = 116), 47 min for Eurasian Griffon (n = 6), and 84 min for White-rumped Vulture (n = 61; 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 ). Outside of these various dominance gradients, the Eurasian Griffon has also been observed in mixed foraging flocks with the Himalayan Griffon (Gyps himalayensis), which were regularly seen in the Assy-Turgen region of the Tien Shan mountains (Kazakhstan), near the Assy-Turgen Observatory (Katzner, Sklyarenko, personal communication).

In addition to these dominance gradients when feeding at a carcass, the Eurasian Griffon has also been documented interacting with the Bearded Vulture while the latter species was dropping bones onto rock slabs to break them up. In the Pyrenees in Spain, groups of Eurasian Griffon (mean 2.3, range 1–5, n = 30) descended upon Bearded Vulture ossuaries to pirate bone fragments (374 Bertrán, J., and A. Margalida (1997). Griffon vultures (Gyps fulvus) ingesting bones at the ossuaries of bearded vultures (Gypaetus barbatus). Journal of Raptor Research 31(3): 287–288. Close ).

During the breeding season, the Eurasian Griffon has also been documented to interact with many species, which can take the form of territorial interactions, interactions over food, or formation of multi-species colonies, among others. Many species also react agonistically toward the Eurasian Griffon; in one study, the Bearded Vulture showed aggressive territorial behavior toward the Eurasian Griffon during the breeding season. However, territorial behavior was more closely associated with defense of breeding space rather than defense of a specific nest site (375 Bertran, J., and A. Margalida (2002). Territorial behavior of Bearded Vultures in response to Griffon Vultures. Journal of Field Ornithology 73(1): 86–90. Close ). In another study, a Peregrine Falcon (Falco peregrinus) pair nested within 100 m of a Eurasian Griffon nesting pair in Crimea, where the falcons attacked flying vultures constantly. A Eurasian Griffon nestling that was 20 d old was observed on 5 May in the nest; three days later, it was found dead and emaciated (376 Matus, A. A. (2002). To the breeding biology of Griffon Vulture in the Crimea. Berkut 11(1): 121–123. Close ). Not all species act aggressively toward the Eurasian Griffon during the breeding season; a Ruddy Shelduck (Tadorna ferruginea) pair and an Eurasian Eagle-Owl (Bubo bubo) pair nested within 30 m of a Eurasian Griffon colony in the Caucasus (Russia), but no interactions were observed (377 Karavayev, A. A. (2019). Materialy nablyudeniy v kolonii belogolovogo sipa Gyps fulvus v Karachayevo-Cherkesii. Russkiy Ornitologicheskiy Zhurnal 28, Ekspress-vypusk 1772: 2315–2323. Close ). A Ruddy Shelduck also nested among Eurasian Griffon in the cliffs of ravines near the Sea of Galilee, Israel (378 Tristram H. B. (1884). The Survey of Western Palestine. The Fauna and Flora of Palestine. The Committee of the Palestine Exploration Fund, London. Close ).

While nesting, other species have also been documented stealing food from Eurasian Griffon nests meant for nestlings. The Egyptian Vulture has been documented stealing food from a Eurasian Griffon nest in multiple studies, including one that landed near an incubating bird and stole food (379 Tella, J. L., and I. Torre (1990). Observaciones sobre relaciones cleptoparasitarias interespecíficas en el Alimoche (Neophron percnopterus). Butlletí del Grup Català d’Anellament 7: 33–35. Close ). In another instance, a pair of Egyptian Vulture appeared to coordinate and harass a Eurasian Griffon nestling that was recently brought food by an adult for 15 min until the nestling moved from the nest and the Egyptian Vulture pair stole the food (380 Camiña, A. (2017). Cooperative kleptoparasitism in a pair of Egyptian Vultures Neophron percnopterus in northern Spain. Vulture News 73: 29–32. Close ). In the Caucasus (Russia), a pair of Eurasian Magpie (Pica pica) regularly visited nests of a Eurasian Griffon colony and stole the food regurgitated by adults for the nestlings (377 Karavayev, A. A. (2019). Materialy nablyudeniy v kolonii belogolovogo sipa Gyps fulvus v Karachayevo-Cherkesii. Russkiy Ornitologicheskiy Zhurnal 28, Ekspress-vypusk 1772: 2315–2323. Close ).

In addition to the interactions noted above, the Eurasian Griffon may also occupy aeries built by other species. In Navarra and Zaragoza (Spain), the Eurasian Griffon usurped 2.6% aeries occupied by the Egyptian Vulture (n = 77), 44.4% of Bearded Vulture aeries (n = 9), 7.6% of Golden Eagle (Aquila chrysaetos) aeries (n = 118), and 39.1% of Bonelli's Eagle (Aquila fasciata) aeries (n = 23). In one case, a Egyptian Vulture pair usurped a Eurasian Griffon nest for a year. In Cataluña (Spain), 40% (n = 70) of Bearded Vulture nests were usurped by other species, mainly (81%) Eurasian Griffon (381 Margalida, A., and D. García (1999). Nest use, interspecific relationships and competition for nests in the Bearded Vulture Gypaetus barbatus in the Pyrenees: influence on breeding success. Bird Study 46(2): 224–229. Close ). In Dana Biosphere Reserve (Jordan), a pair of Bonelli's Eagle was recorded nesting on a cliff in 2010; the same nest was used by nesting Eurasian Griffon in 2012 and 2014 (382 Al-Awaji, M. (2015). Competition on favourable nest location between Griffon Vulture and Bonelli's Eagle in Dana Biosphere Reserve. Jordan Journal of Natural History 2:72–75. Close ). In Romania, an incubating White-tailed Eagle (Haliaeetus albicilla) was shot on 29 February; on 11 March the nest was occupied by a pair of Imperial Eagle (Aquila heliaca), and on 23 April an incubating Eurasian Griffon was observed on the nest (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 ). The expropriation of aeries by Eurasian Griffon has increased in frequency over the years, likely because the expanded distribution of the species now overlaps with that of other raptors. Other factors, such as the greater body weight and earlier breeding season of the Eurasian Griffon gives it dominance over other cliff-dwelling raptors (383 Fernández, C., and J. A. Donázar (1991). Griffon Vultures Gyps fulvus occupying eyries of other cliff-nesting raptors. Bird Study 38(1): 42–44. Close ).

The Eurasian Griffon has also been documented nesting in mixed species colonies. In Kazakhstan, Eurasian Griffon pairs and Himalayan Griffon pairs were observed on several occasions breeding at the same colony (117 Katzner, T., A. Gavashelishvili, S. Sklyarenko, M. McGrady, J. Shergalin, and K. Bildstein (2004). Population and conservation status of griffon vultures in the former Soviet Union. In Raptors Worldwide ( R. D. Chancellor and B. U. Meyburg, Editors). WWGBP/MME. pp. 235–240. Close ). Colonies that appear to have both Eurasian Griffon and Himalayan Griffon were observed north of Zharkent, very close to the Chinese border, east of Altyn Emel National Park (Kazakhstan; Katzner, Sklyarenko, personal communication). In another colony of 15–20 Eurasian Griffon nests at Chulak (Kazakhstan), one Himalayan Griffon was present, although it was unclear whether it was nesting (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 addition to nesting, the Eurasian Griffon may also roost with other species. In one case, two Eurasian Griffon were observed roosting with a Lappet-faced Vulture (Torgos tracheliotos) at Wadi al Butm (Jordan) on 16 April 1963 (175 Andrews, I. J. (1995). The Birds of the Hashemite Kingdom of Jordan. Published privately, Musselburgh, Scotland. Close ).

A Eurasian Griffon migrating across the Strait of Gibraltar was harassed by a Yellow-legged Gull (Larus michahellis) and fell into the sea (356 Cortés, J. (2009). A migrant griffon vulture Gyps fulvus swims to Spain. Gibraltar Bird Report 9: 48–49. Close ). In Corsica, harassment of a Eurasian Griffon by a Yellow-legged Gull was also observed (384 Jourdain, F. C. R. (1912). Notes on the ornithology of Corsica.-Part III. Ibis 54(1):63–82. Close ).

Kinds of Predators

The Common Raven (Corvus corax) (272 Donázar, J. A. (1993). Los Buitres Ibéricos: Biología y Conservación. J. M. Reyero, Madrid, Spain. Close ), Egyptian Vulture (Neophron percnopterus) (385 Barcell, M., J. R. Benítez, F. Solera, B. Román, and J. A. Donázar (2015). Egyptian Vulture (Neophron percnopterus) uses stone-throwing to break into a Griffon Vulture (Gyps fulvus) egg. Journal of Raptor Research 49(4): 521–522. Close ), and Yellow-legged Gull (Larus michahellis) (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 ) are potential egg predators of the Eurasian Griffon; the Common Raven also occasionally predates nestlings (386 Grubač, B. (2000). The Raven (Corvus corax) as a predator of a young Griffon Vulture (Gyps fulvus). In Bearded Vulture annual report 2000 (H. Frey, G. Schaden and M. Bijleveld van Lexmond, Editors), Foundation of the Conservation of the Bearded Vulture, Wassenaar, The Netherlands. pp. 102–103. Close ). Red fox (Vulpes vulpes) has also been recorded predating a Eurasian Griffon nestling (387 Catala, M. C., and J. A. Gil-Delgado (1988). Predación de zorro (Vulpes vulpes) sobre un pollo de buitre leonado (Gyps fulvus). Doñana Acta Vertebrata 15(2): 245–247. Close ).

Manner of Depredation

Two Common Raven practiced coordinated harassment of an incubating Eurasian Griffon; one raven pecked at the vulture while the other, on the opposite side, waited for it to move away to gain access to the egg (387 Catala, M. C., and J. A. Gil-Delgado (1988). Predación de zorro (Vulpes vulpes) sobre un pollo de buitre leonado (Gyps fulvus). Doñana Acta Vertebrata 15(2): 245–247. Close , 272 Donázar, J. A. (1993). Los Buitres Ibéricos: Biología y Conservación. J. M. Reyero, Madrid, Spain. Close ). On one occasion, a Common Raven pair and Egyptian Vulture pair harassed an incubating adult simultaneously (unsuccessfully) for over 45 min (387 Catala, M. C., and J. A. Gil-Delgado (1988). Predación de zorro (Vulpes vulpes) sobre un pollo de buitre leonado (Gyps fulvus). Doñana Acta Vertebrata 15(2): 245–247. Close ). At one abandoned nest, an Egyptian Vulture pair used stones to break a Eurasian Griffon egg and fed on its contents (385 Barcell, M., J. R. Benítez, F. Solera, B. Román, and J. A. Donázar (2015). Egyptian Vulture (Neophron percnopterus) uses stone-throwing to break into a Griffon Vulture (Gyps fulvus) egg. Journal of Raptor Research 49(4): 521–522. Close ).

At Gir National Park (India), two vultures—a White-rumped Vulture (Gyps bengalensis) and either an Indian Vulture (Gyps indicus) or an Eurasian Griffon—approached too close to carcasses and were killed by a lion (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 ).

Response to Predators

Nestlings usually flatten out in the nest when approached by a person. Young chicks defecate in defense; another nestling response is regurgitation of food. Some nestlings try to run away and crawl into crevices; others are aggressive and bite the intruder (301 Fernández, J. A. (1977). Comportamiento del buitre leonado (Gyps f. fulvus) en nido. Ardeola 22: 29–54. 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 ). Captive chicks were observed hiding their heads in the nesting material (16 Thaler, E., S. Maschler, and V. Steinkellner (1986). Vergleichende Studien zur Postembryonalentwicklung dreier Altweltgeier: Bartgeier, Schamtzgeier und Gänsgeier. Annalen des Naturhistorischen Museums in Wien. Serie B für Botanik und Zoologie 88–89B: 361–376. Close ). Adult Eurasian Griffon generally leave the nest upon the arrival of a person, but some females remain in the nest and attack the intruder (301 Fernández, J. A. (1977). Comportamiento del buitre leonado (Gyps f. fulvus) en nido. Ardeola 22: 29–54. Close ).

To reduce risk of predation while feeding on a carcass, the Eurasian Griffon has been shown experimentally to prefer sites with good visibility around the carcass, allowing birds to detect predators and escape (388 Gavashelishvili, A., and M. J. McGrady (2006). Geographic information system-based modelling of vulture response to carcass appearance in the Caucasus. Journal of Zoology 269:365–372. Close ). In the same study from Georgia, it preferred landing at carcasses where corvids were already feeding, which could be interpreted as a sign of relative security (388 Gavashelishvili, A., and M. J. McGrady (2006). Geographic information system-based modelling of vulture response to carcass appearance in the Caucasus. Journal of Zoology 269:365–372. Close ). It has also been shown to assess the risk of predation based on the availability of food and its level of hunger, and can modify its anti-predator behavior. In experiments with supplemental feeding, it reduced the reaction time to food exposure and the distance at which it would flush from a potential predator from one day and 250 m, to 2.8–19.2 min and 15.2–52.2 m, respectively, depending on food availability (389 Zuberogoitia, I., J. E. Martínez, A. Margalida, I. Gómez, I., A. Azkona, and J. A. Martínez (2010). Reduced food availability induces behavioural changes in Griffon Vulture Gyps fulvus. Ornis Fennica 87(2): 52–60. Close ).