Cinereous Vulture Aegypius monachus Scientific name definitions

Alfredo Salvador
Version: 2.0 — Published May 12, 2023



Cinereous Vulture has a prolonged breeding season, probably as an adaptation to the unpredictable availability of carrion during reproduction. It nests on trees, rocks, or cliffs. Aerial displays occur from December until February. Both sexes contribute to construction and maintenance of the nest. A single brood of one egg (rarely two) is laid between February and early May, although replacement clutches can occur. The male and female take turns incubating the eggs while the other forages; the incubation period lasts 50–68 days. Hatching occurs from mid-March through May, with fledging during August and September, 88–137 days after hatching. The immature stage lasts 1‒4 years.


Pair Formation

Courtship flights are observed in Spain between December and February (205), and in Crimea in February (221). There is no information about mate selection (253).

Nest Building

The first arrangements of the nest in France started on 21 December and continued until 14 April, with a mean of 12 February (n = 39; 281). Nest construction started in Uzbekistan between 10 and 20 February (77) and nest repair in Azerbaijan also starts in February (67).

First Brood

Laying in Spain occurs between early February and late April (16, 282). In the Lozoya Valley (Madrid, Spain), earliest laying was on 6 February and latest on 7 May (average 10 March) (283). In France, mean laying date was 5 March (range 8 February‒18 April, n = 84) (281). In Dobrogea (Romania), laying occurred between 15 March and 8 May (271) and in Crimea during March and early April (166); on 5 March 1989, the height of freshly fallen snow in the nesting area was 117 cm. Along the upper Ulu-Uzen River (Crimea), on 30 March, pairs were repairing their nests; however, no eggs were recorded in any of 18 known nests at this point (221).

In the middle Sakarya Valley (Türkiye), laying took place between 18 February and 30 April (284); in Armenia between 22 February and 22 March (222); in the south-central Caucasus during late February and early March (235); in the Tien Shan Mountains (western China), usually in late February and early March (228); in Uzbekistan between 20 February and 10 April (77); and in Central Asia as a whole laying is reported to commence in early January and end in late April (77).

The mean hatching date in France was 1 May (range 6 April‒10 June) (281). Hatching occurs in Crimea between late April and first half of May (166). In middle Sakarya (Türkiye) the first chicks hatched in the third week of March (284) and in Armenia between 22 April and 16 May (222).

In France, the mean fledging date was 20 August (range 28 July‒1 October) (281); in middle Sakarya (Türkiye), fledging occurred from 1 August to 30 September (284); in Armenia between 16 August and 13 September (222); and in Crimea from the second half of August to the first half of September (166).

Second/Later Broods

In Spain, replacement clutches were recorded in 4.76% of nests where the first egg was lost before 15 days of incubation had elapsed (n = 42), and were laid at least 15 days after the first clutch was lost (282). In the south-central Caucasus two cases of replacement clutches have been recorded (235).

Nest Site

Microhabitat and Site Characteristics

In Europe nests are nearly always on trees, although nests on rocks have been recorded in Spain within very dense thickets of vegetation (Cistus sp. and Erica sp., n = 4) (285). In 1920, Munn (286) observed two nests in the Alcudia area of Mallorca (Spain), one in a cavern, the other on a ledge, and another nest on a rock was recorded in 2020‒2021 on the same island (287). In East Asia, the species nests on trees, rocky outcrops, and cliffs (80), and cliff-nesting is also suspected in Azerbaijan (67). Typically, the nest is sited on the top of the tree, occasionally on a side branch (16, 166) and there is a record in Armenia of a nest that spanned two juniper (Juniperus) trees (171).

Various studies into the selection of nest sites have reported that the species selects steep, often south-facing slopes, especially the middle or higher parts, on which to nest. It chooses large trees that often stand apart from other trees. All these characteristics facilitate access to and from the nest, using thermal currents and slope winds (288). Another characteristic of nest location is that the Cinereous Vulture selects sites furthest from human disturbance (257, 160, 258, 161, 256, 289, 164).

Nest site use was examined at two colonies that used pines in the Sierra de Guadarrama (Spain). One was in a maritime pine (Pinus pinaster) forest at 930‒1,387 m above sea level, and the other was in a Scots pine (Pinus sylvestris) forest, at 1,315‒2,196 m. In both colonies, nest trees were further from neighboring trees and tended to have a greater dbh. The vultures selected trees on the middle or upper third of steep slopes, and all nests identified were sited between 1,090 m and 1,880 m above sea level, with few roads in the surroundings (257). In another highland area (Sierra de Gredos) in the same country, the species nested in rugged areas at relatively high elevations, in mature but relatively open pine forest, whilst in a lowland area (Sierra Morena) it bred in open areas with steep slopes far from human disturbance (160).

In seven colonies in Extremadura (Spain), the Cinereous Vulture selected steep areas far from human activities. Climatic factors influenced nest site selection, with colonies tending to avoid both the coolest zones at higher elevations (Gata-Hurdes) and the warmest areas at lower altitudes (Monfragüe colony) (161). In Hornachuelos Natural Park (Córdoba Province, Spain), nests were on steeper slopes with lower solar radiation, in larger homogeneous patches with a high proportion of cork oak cover, and further from roads, villages, and patch edges (n = 43) (164). In Monfragüe National Park (Cáceres, Spain), nests are sited on cork oak (Quercus suber), holm oak (Quercus ilex), Portuguese oak (Quercus faginea), olive (Olea europaea), strawberry tree (Arbutus unedo), and prickly juniper (Juniperus oxycedrus) (290). In Castilla y León, in Segovia Province, nests are on Scots pine (Pinus sylvestris), in Ávila Province on maritime pine (Pinus pinaster), black pine (Pinus nigra), Scots pine, and prickly juniper, and in Salamanca Province on holm and cork oaks (291).

In the western Sierra Morena (Spain), most nests were on cork oak (91.80%), with a small proportion on holm oak (6.55%) and Portuguese oak (1.64%, n = 61) (205). In the Sierra Pelada (Huelva, Spain), changes were recorded in nest trees due to the growth of pine plantations. In the 1970s, 37% of nests were on cork oak, 37% on holm oak, and 6% on Portuguese oak, but in 2009, 51.8% were on stone pine (Pinus pinea), 21.6% on cork oak, 17.65% on maritime pine, 7.8% on holm oak, and 1.2% on strawberry trees (188). On the island of Mallorca it nests on pine trees (Pinus halepensis) located on sea cliffs (292, 293, 294, 295, 184, 296).

In the reintroduced population in the Massif Central (France), all of the known nests were on Scots pine (220). In Dadia Nature Reserve (Greece), all nests were on black pine and Turkish pine (Pinus brutia) (258), and the Cinereous Vulture selected trees with greater diameter, lower height, lower number of trees in the environs the nest tree, steeper slopes, and greater distance from forest roads (n = 25) (258). In Crimea, it nests mostly on black pine and, to a lesser extent, Scots pine, with one nest on Juniperus foetidissima (166, 221). In northern Bosnia nests are built on beech, more rarely on oak, and in Herzegovina on black pine (15).

In Türkiye, the Türkmenbaba and Köroğlu Dağları populations nests on black pine (72, 297). In Georgia the nests are located on Juniperus foetidissima, Juniperus polycarpos, and Juniperus rufescens (169). In Armenia nests are on Juniperus polycarpos (222). In Azerbaijan a nest was found at a height of 1 m on pistachio and juniper branches that had grown together (170) and most nests in this country are on south-facing slopes and no more than 6 m above ground (67).

In the south-central Caucasus, the species nested mainly on Juniperus foetidissima (n = 91), followed by Juniperus polycarpos (n = 21), Pistacia mutica (n = 6), and Pinus eldarica (n = 6). In the northern Caucasus, known nests were all on pines (235). Nests on pines have been recorded in the Russian Caucasus (298, 299). In Georgia, the species selected mature junipers on steep slopes in rugged semi-arid landscapes for nesting, mostly on north-facing sites, and far from populated areas (n = 31) (256).

In Pakistan nests were recorded on junipers (Juniperus macropoda, n = 14) and on cliffs (n = 34), at 3,000 m above sea level or higher (300). In Central Asia (Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, and Uzbekistan), nests sited on trees, cliffs, and slopes, but also on bushes or low shrubs in the mountains (77, 301). In Central Kopetdag (Turkmenistan), the Cinereous Vulture nests on junipers (Juniperus turcomanica) (302). In the Nuratau Mountains (Uzbekistan), all nests were on almond trees (Prunus bucharica) 1.5–5.0 m above ground, on slopes of 25-45°, at a mean elevation of 1,487 m ±167 SD (range 1,000–1,880 m, n = 101) (303). In the northern Tien Shan Mountains (Kazakhstan), nests (n = 6) were recorded on cliffs in rocky canyons, at 1,370–1,500 m (304).

In Mongolia, the species nests on rock outcrops, Siberian elm (Ulmus pumila), Siberian pine (Pinus sibirica), Juniperus pseudosabina, Juniperus sabina, Prunus sp., and bushes (173, 80). In Ikh Nart Nature Reserve (Mongolia), pairs nested on trees, mainly Siberian elm (n = 103), but also rock outcrops and ledges (n = 242). In Gun Galuut Nature reserve, Choir and Sansar Mountains pairs nested on rocky ledges (174). In northern Mongolia, nests (n = 4) were found on cliffs (305) and in eastern Mongolia a nest was found on an elm in Ongon Els and another was on a rock near the Kherulen Valley (306).

A nest in the Republic of Buryatia, Russia, was atop a larch tree on a south-facing slope 2,050 m above sea level, near the upper limit of the trees (82). In Altai-Sayan region (Russia), 90% of nests were on rocky ridges, with 5% on riverine cliffs and rocks (n = 60). Mean elevation of nests above sea level was 1,558.5 m (range 1,066‒2,569 m). Mean height of rocky ledges on which nests were constructed was 4.5 m (0.3–40.0 m). Most nests on cliffs faced south (31.67%), southeast (18.33%) and southwest (15.0%) (n = 60) (81). In Tuva Republic (Russia), nests were on rocks, ledges, and screes, at 1,500–1,600 m above sea level (n = 4; 280).

In China, the species nests on junipers, cliffs, and rocks (80). In the Tien Shan Mountains (western China), nests (n = 4) they were on cliffs, 9‒10 m tall, at 2,300‒2,900 m (228).


Construction Process

Nests are built by both sexes (16). Each year fresh material including branches is added both throughout the nesting period and at other seasons of the year; they also take branches from other nests (16). A nest in Kazakhstan examined over two consecutive years became 5–7% larger in the course of the second year (250).

Structure and Composition

Nests in Spain were constructed with branches of cork oak, Pinus sp., Phillyrea sp., Erica sp., Cistus sp., and Rubus sp. The interior comprises finer branches, sometimes augmented by wool, scraps of fur, and pine needles (16). In Armenia and Azerbaijan, nests were built using large (mainly juniper) and thinner branches, dry twigs, dry leaves, dry herbaceous plants, bark, manure, and wool; twigs were up to 1 m long and 1‒3 cm thick (171, 67). In Central Kopetdag (Turkmenistan), the nest is constructed of dry branches of juniper (Juniperus turcomanica) and Turkmen maple (Acer turcomanicum) (302). A nest in the Shalkar-Nura Mountains (Kazakhstan) contained saxaul (Haloxylon ammodendron) branches (307). In Tuva Republic (Russia), nests were built using twigs of poplar (Populus), larch, and Siberian peashrub (Caragana arborescens) (n = 4; 280). In Dobrogea (Romania), nests were sited on oak (Quercus), linden (Tilia), and pear (Pyrus) trees (18).

It has been suggested that use in nests of green plant material during the breeding season by birds, including the Cinereous Vulture, may prevent ectoparasites (308). However, this hypothesis remains unstudied in the present species. Grass often grows in old (inactive) nests (67).


The mean size of new nests was 91 cm in diameter and 39 cm in height (n = 7). In subsequent years the birds continue to accumulate material, achieving a mean diameter of 174 cm and height of 92 cm (n = 61) (205).

In the Lozoya Valley (Madrid, Spain) colony the maximum diameter of nests averaged 161.3 cm and mean height was 68.7 cm (n = 35) (309). Nests have a mean diameter of 1.6 m in Córdoba (n = 12) (310), and 1.66 m in the Sierra de San Pedro (Cáceres, Spain) and Umbría de Alcudia (Ciudad Real, Spain) (n = 126) (272). In Dobrogea (Romania), the largest nest had a diameter of 260 cm and height of 240 cm (18).

In the south-central Caucasus, nests measured 120–215 cm outer diameter, 40–85 cm inner diameter, 40–120 cm height, and 15–40 cm cup depth (n = 8; 235); data from Azerbaijan are within the same range (67). In Armenia, nests averaged 150.6 × 192.1 cm outer diameter, 51.9 × 55.4 cm inner diameter, 40.0‒130.0 cm height (mean 79.6 cm), and 4‒14 cm cup depth (mean 8.4 cm) (n = 14; 171), or 160 cm long, 134 cm wide, 53 cm high, 49 cm inner diameter, and 7 cm cup depth (n = 7) (222). In Ikh Nart (Mongolia), mean diameter was 174.2 cm ± 4.6 SE, mean height 75.5 cm ± 4.5, and mean volume 3.92 m³ ± 0.39 SE (n = 36) (311). In Tuva Republic (Russia), nest diameter and height ranged from 115–165 cm and 30–45 cm, respectively (n = 4; 280).

The accumulation of material sometimes causes nests to collapse (271, 16, 312, 272, 281).


Information needed.

Maintenance or Reuse of Nests

Each pair uses a variable number of nests over time (171, 309, 166); in Azerbaijan, it has been suggested that these are spaced 100‒500 m apart (67). At the Lozoya Valley colony (Madrid, Spain), the number of nests per pair varied from one to nine, with a mean of 2.4 nests per pair during the period 1997‒2005 (309). In France, the mean continuous duration use of one nest by a pair was 3.5 years ± 2.04 SD, and there was a tendency to increased duration at a single nest with the pair’s breeding success (281).



Roundish elliptical to roundish oval (1).


Across multiple populations, mean egg size is 90.3 × 70.2 mm (n = 166; 313), 90.0 × 69.7 mm (n = 150; 314), or 91.71 ± 4.02 × 69.72 ± 2.77 mm (n = 267) (282). In a sample from Dobrogea (Romania), mean egg size was 89.5 × 66.6 mm (n = 117; 18), in Spain mean egg size was 91.7 × 68.7 mm (n = 93; 1), in the southern Caucasus 84.0–96.3 × 64.5–72.5 mm (n = 61; 235), and in Armenia 90.3 × 70.9 mm (n = 13; 171). A single egg from Azerbaijan measured 98 × 68 mm (67). In the Nuratau Mountains (Uzbekistan), mean egg size is 91.04 (range 69.2–102.3) × 69.27 (range 51.4–75.9 mm) (n = 260) (303). Egg size is significantly different between the Iberian Peninsula and elsewhere in western Europe, and Asia (282).


Egg mass varies from 210.5 to 280.0 g (1, 282). Mean egg mass in Armenia was 231.5 g (range 168–277, n = 13; 171). In the south-central Caucasus, egg mass ranged from 221.5–247.3 g (n = 36; 235).


In the Nuratau Mountains (Uzbekistan), mean egg volume is 223.6 cm3 (range 93.2–287.3, n = 260) (303).

Eggshell Thickness

Thickness is estimated at 0.73 mm (314).

Color and Surface Texture

Eggs are white (82.13%) or cream (17.83%) (282). Egg color rarely is bright yellowish red (1). An egg from the Shalkar-Nura Mountains (Kazakhstan) was dirty white with brown-yellow spots (307). Spotless white eggs are rare (4.26%). Spots are dark brown, dark and reddish chestnut, greenish gray, and violet. On any given egg, spots can be a single color (49.61%), two colors (41.86%), three colors (3.88%), or four (0.39%), with the commonest colors reddish and dark chestnut, and dark brown, violet, and greenish-gray spots scarce (282).

Clutch Size

Clutch size is usually a single egg and two-egg clutches are rare. One clutch of two eggs was found in a sample in museum collections (n = 264) (282). In the south-central Caucasus, one of just 503 clutch involved two eggs (235). In Spain, one egg and one chick were seen in a nest from a total of 182 nests examined; a week later the egg had disappeared (282). In Türkiye, three nests of 20 had two-egg clutches (315). In Babadag Forest (Romania), another nest with two eggs was found (n = 370) (271). On the island of Mallorca, during the period 1973‒2005 just one nest with two eggs was recorded, in 1975 (296). In Nuratinsky Reserve (Uzbekistan), just one nest had two eggs (n = 100 clutches) (77). In the Nuratau Mountains (Uzbekistan), two clutches of two eggs were found (n = 258) (303). In Grand Causses, France, one nest with two eggs was found (n = 83) (281), another with two eggs was found in the Sengilen Mountains, Altai-Sayan, Russia (n = 33) (81), and, a third nest with two eggs was recorded in Tuva Republic, Russia (n = 4; 280).

Egg Laying

Information needed.


Incubation Period

Previously estimated at 50‒55 days (181, 244, 2), but detailed information from Spain has revealed a wider incubation period. In eggs hatched in the wild, incubation periods of 50‒54 days (n = 5) and 58‒62 days (n = 2) have been recorded (282), and at the Lozoya Valley colony the mean incubation period was 59 days (range 51‒68, n = 25) (316). In south-central Caucasus, the incubation period lasts 53 days (n = 2), 54 days (n = 16), 55 days (n = 6), or 56 days (n = 1) (235).

Parental Behavior

The male and female take turns incubating, while the other individual forages. Continuous incubation varied between six hours and five days, and averaged 41.92 hours (282). Incubating adults were observed standing 9‒12 times during the daylight hours for periods shorter than ten minutes to turn the egg or preen (282, 221).


Shell Breaking and Emergence

Information needed.

Parental Assistance and Disposal of Eggshells

Information needed.

Young Birds

Condition at Hatching

Semi-altricial and nidicolous (2, 317).

Growth and Development

In Spain, differences in mass growth between nestlings has been observed (318, 282); some grow rapidly but reach a low asymptote, whereas in others mass growth is slower during the first days and reach a higher asymptote sooner (282). At Ikh Nart (Mongolia), chicks grow linearly until prior to fledging; the mass growth curve until 1 September was highly significant (intercept 6.14 ± 0.28 SE, slope 0.05 ± 0.01 SE, R² 0.37, F 54.87, P <0.001, n = 107) (311).

In the Tien Shan Mountains (China), a hatchling born on 13 April, had a body mass of 160 g; by 17 May mass was 1.5 kg, on 14 June 5.65 kg, on 3 July 8.45 kg, and on 14 July 8.56 kg (228). In a sample from Mongolia of genetically sexed nestlings close to fledging, there was a tendency for males to have lower body mass (8,582.5 g ± 654.0 SD, n = 20) than females (9,010 g ± 953.8 SD, n = 26, P = 0.09) (319).

Parental Care


During at least the first 20 days of life, adults ensure that the nestling is brooded for most of the time (16, 10). Adults also shade the chick, first using its body when the chick is still relatively small but with its open wings when the nestling is older (16). Nest attendance by the breeding pair varies with nestling age: one adult was present 99.32% of the time during the nestling’s first two months of life, 92.48% of the time at age 2‒3 months, and 75.19% when older than three months (282).


The nestling is fed 2‒9 times per day during the first weeks of life (10) or 1‒5 times a day over the first 1.5 months of life (221), but rarely twice a day before fledging (77). In the Tien Shan Mountains (China), the number of daily feeds decreased from 4‒6 times per day in April‒May to 0‒1 in June‒July (228). Fledglings continue to be provisioned by their parents for several months after they fledge (77).

The nestling is fed both solid food and watery liquids (10). Young chicks receive small pieces of solid food in their bills. Feathered chicks peck the adult with the neck stretched upwards and body crouched down, moving the closed wings, to stimulate the adult to regurgitate food; the chick then takes food from the adult’s mouth or the floor of the nest (10).

Cooperative Breeding

Polygynous breeding trios have been detected in Sierra Norte Natural Park (Sevilla, Spain). In 2006 the first known trio formed, in 2008 there were two, and in 2009 there were three. In all cases, at least one individual had a non-adult head pattern, but the adults shared incubation duties, and one or two nestlings was recorded in each of the nests. A genetic analysis identified that a male and two females formed one trio, with each female being the mother of one of the nestlings and the male fathering both of the nestlings (320, 188, P. M. Dobado, personal communication). During 2015 a trio was observed at a nest in the Sierra de Hornachuelos (Córdoba, Spain), but breeding was not recorded (P. M. Dobado, personal communication).

Brood Parasitism by Other Species

Not reported.

Fledgling Stage

In the Lozoya Valley (Madrid, Spain) colony, the mean period in the nest was 114 days (range 88‒137, n = 28) (316). Also in Spain, fledglings were observed begging for food 80‒100 days after leaving the nest (282). In the Sierra de San Pedro (Cáceres, Spain), most of this dependency period was spent less than 5 km from the nest (n = 4; 162).

In the central Tien Shan Mountains (China), a juvenile returned to its nest during the first ten days after fledging, on 22 July, and remained within just 130 m radius of it; thereafter during August the young bird moved over an area of ​​30 km², which in September increased to 156 km², but still returned to the nest on a daily basis (228).

In a sample from the Sierra de San Pedro (Cáceres Province) colony (n = 57), fledging sex ratio (male: female) was 54.5, 50.0, and 65.0, in 1998, 1999, and 2000, respectively. No significant differences in sex ratio were found in any year (321).

Immature Stage

The immature stage generally lasts several years and extends from independence until they breed for the first time at 3‒7 years old (281, 187).

In the Sierra de San Pedro (Cáceres, Spain), considering the date of independence as the first complete month the young remained more than 5 km from the nest, the mean age of independence was 217 days old (range 210‒239, n = 4; 162). At the Lozoya Valley colony (Madrid, Spain), fledglings became independent at a mean age of 202 days (range 160‒282, n = 4); the oldest juvenile did not gain independence until mid-February, coinciding with the start of the next breeding season and the young’s expulsion by the adults from the nest area (187).

Monitoring over 224‒486 days of Cinereous Vultures equipped with satellite transmitters (n = 4) as nestlings in the Lozoya Valley revealed that some individuals dispersed distances of 300‒350 km in 5‒10 days within their first year of life, whereas others moved away much more gradually; some returned periodically to their natal colony, but dispersal extended over much of western Iberia (187). In juveniles from Extremadura equipped with satellite transmitters (n = 4), there were birds that also dispersed long distances and others that moved long distances over short periods but returned to their natal colony (162). Cinereous Vultures fitted with GPS transmitters as fledglings in Cabañeros National Park, Ciudad Real, Spain (n = 9) and followed for 428‒984 days, spent longer distances from the natal colony during spring/summer than in autumn/winter (248).

Recommended Citation

Salvador, A. (2023). Cinereous Vulture (Aegypius monachus), version 2.0. In Birds of the World (G. M. Kirwan, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.cinvul1.02