Plumages, Molts, and Structure

Cinereous Vulture has 10 functional primaries (numbered distally, from innermost p1 to outermost p10), usually 23–25 secondaries (numbered proximally, from innermost s1 to outermost s20–s22 and including three tertials numbered distally, from t1 to t3), and 12 rectrices (numbered distally on each side of the tail from innermost r1 to outermost r6). Accipitrine hawks are diastataxic (see 8 Bostwick, K. S., and M. J. Brady (2002). Phylogenetic analysis of wing feather taxis in birds: Macroevolutionary patterns of genetic drift? Auk 119:943–954. Close ) indicating that a secondary has been lost evolutionarily between what we now term s4 and s5. Wings are broad and rounded, the wing morphology usually p8 ~ p7 > p6 > p5 ~ p9 > p10 and with p5‒p10 notched and p4‒p9 emarginated (9 Cramp, S., and K. E. L. Simmons, Editors (1980). The Birds of the Western Palearctic. Volume 2: Hawks to Bustards. Oxford University Press, Oxford, UK. Close ). The tail is wedge shaped. Little or no geographic variation in appearance has been reported (see Systematics). See Molts for molt and plumage terminology; reports of alternate plumages (1 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 , 2 Cramp, S., and K. E. L. Simmons, Editors (1980). The Birds of the Western Palearctic. Volume 2. Hawks to Bustards. Oxford University Press, Oxford, UK. Close ) are likely based on protracted prebasic molts.

The following is based primarily on plumage descriptions in Suetens and van Groenendael (10 Suetens, W., and P. van Groenendael (1966). Sobre ecología y conducta reproductora del Buitre Negro (Aegypius monachus). Ardeola 12(1):19–44. Close ), Glutz von Blotzheim (1 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 ), Cramp and Simmons (9 Cramp, S., and K. E. L. Simmons, Editors (1980). The Birds of the Western Palearctic. Volume 2: Hawks to Bustards. Oxford University Press, Oxford, UK. Close ), and Forsman (11 Forsman D 1999 The Raptors of Europe and the Middle East. A Handbook of Field Identification. T & AD Poyser, London Close , 3 Forsman, D. (2016). Flight Identification of Raptors of Europe, North Africa and the Middle East. Bloomsbury, London, UK. Close ), along with examination of Macaulay Library images; see de la Puente and Elorriaga (12 de la Puente, J., and J. Elorriaga (2012). Primary moult and its application to ageing in the Black Vulture Aegypius monachus. In The Black Vulture: Status, Conservation and Studies. Proceedings of the First International Symposium on the Black Vulture Aegypius monachus (Cordoba, Spain, 21–23 October 2004) (P. M. Dobado and R. Arenas, Editors), Consejería de Medio Ambiente, Junta de Andalucía, Córdoba, Spain. pp. 259–269. Close ) for ageing criteria in Cinereous Vulture, and Zuberogoitia et al. (13 Zuberogoitia, I., J. De La Puente, J. Elorriaga, R. Alonso, L. E. Palomares, and J. E. Martínez (2013). The flight feather molt of Griffon vultures (Gyps fulvus) and associated biological consequences. Journal of Raptor Research 47(3): 292–303. Close ) and Pyle (14 Pyle, P. (2008). Identification Guide to North American Birds, Part II: Anatidae to Alcidae. Slate Creek Press, Point Reyes Station, California, USA. Close ) for criteria of similar Accipitrine species. Sexes similar in appearance in all plumages. Definitive appearance may usually be assumed at the Fourth to Sixth Basic plumage, but further study is needed.

Natal Down

Present primarily April‒August, in the nest. First natal down is white-beige or pale smoke-gray, with a mixture of white and brown on the lower foreneck, and some small dark spots on the cheeks. Second down dark fuliginous-brown or dark smoke-gray, with a dirty white hood (15 Reiser, O. (1907). Das Dunenjunge vom Kuttengeier, Vultur monachus L. Ornithologische Monatsschrift 32:331–333. Close , 16 Bernis, F. (1966). El Buitre negro (Aegypius monachus) en Iberia. Ardeola 12(1):45–99. Close , 1 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 , 2 Cramp, S., and K. E. L. Simmons, Editors (1980). The Birds of the Western Palearctic. Volume 2. Hawks to Bustards. Oxford University Press, Oxford, UK. Close ).

Juvenile (First Basic) Plumage

Present primarily September‒May. General coloration of Juvenile Plumage is dark brown, almost black, and darker than in adults. Crown, neck, abdomen, cheeks, chin, and throat black-brown, with bare skin forming a dark face mask, partially framed by the dirty white beak bulges. Contour feathers uniformly dark brown to blackish, without mixed levels of wear as found in later plumages, and with a narrow but clear supercilium above the eye; undertail coverts dark gray-brown. Primaries, secondaries, and rectrices are uniform in wear and narrower than basic feathers, not showing mixed generations of remiges or molt clines (see Definitive Basic Plumage, below). See also Bare Parts for color changes in the bill, iris, and legs and feet by age.

Formative Plumage

A Preformative ("Post-juvenile") Molt of scattered body feathers in December‒March, prior to commencement of the Second Prebasic Molt, may exist in some Cinereous Vultures, as occurs in other Accipitrid and Buteo hawks (17 Pyle, P. (2005). First-cycle molts in North American Falconiformes. Journal of Raptor Research 39(4):378–385. Close ). Formative feathers would occur primarily in February-June at scattered locations on upperparts and breast and would be fresher and intermediate in shapes and appearance between those of juvenile and definitive basic plumages (see images below). Uniformly juvenile wing and tail feathers are retained. See also Bare Parts for color changes in the bill, iris, and legs and feet by age.

Second through Fourth Basic Plumages

Present primarily September (when fresh) to June (when worn). During the second through fourth molt cycles, the black mask begins to reduce as areas of bare skin appear. Erectile feathers on the upper sides of the mantle are darker than in adults. The pale superciliary band extends from behind the eye to the bill (10 Suetens, W., and P. van Groenendael (1966). Sobre ecología y conducta reproductora del Buitre Negro (Aegypius monachus). Ardeola 12(1):19–44. Close ).

Following incomplete molts, body feathers show mixed generations, including retained juvenile feathers in second to fourth basic plumages (12 de la Puente, J., and J. Elorriaga (2012). Primary moult and its application to ageing in the Black Vulture Aegypius monachus. In The Black Vulture: Status, Conservation and Studies. Proceedings of the First International Symposium on the Black Vulture Aegypius monachus (Cordoba, Spain, 21–23 October 2004) (P. M. Dobado and R. Arenas, Editors), Consejería de Medio Ambiente, Junta de Andalucía, Córdoba, Spain. pp. 259–269. Close ), molt patterns that appear to parallel those of Eurasian Griffon (Gyps fulvus) (13 Zuberogoitia, I., J. De La Puente, J. Elorriaga, R. Alonso, L. E. Palomares, and J. E. Martínez (2013). The flight feather molt of Griffon vultures (Gyps fulvus) and associated biological consequences. Journal of Raptor Research 47(3): 292–303. Close ). In second basic plumage, occasionally all juvenile primaries may be retained but more often from one to 5 inner primaries are replaced on each wing, contrasting with retained juvenile primaries among p3‒p10. Up to 10 secondaries may also replaced, usually among the tertials, s1-s2, and s5-s6, following molt sequences typical of Accipitine raptors and initiating Staffelmauser (see Molts). Juvenile feathers may also be retained during the Second and Third Prebasic Molts among upperwing secondary coverts and body feathers, perhaps most often on the rump. By fourth basic plumage all primaries may be replaced or 1-4 juvenile outer primaries (among p7-p10) can continue to be retained among two waves or sets of basic inner primaries and 5-10 juvenile secondaries among s3-s4 and s7-s16 are almost always retained. Body feathering shows mixed levels of wear due to protracted molts and often multiple feather generations.

Fifth and Sixth Basic Plumages

Present primarily October (when fresh) to July (when worn). During the fourth through sixth molt cycles, the dark down on the forehead, crown, and back of head becomes pale brownish-white and the pale supercilium extends from behind the eye to the bill. By these plumages all juvenile flight feathers have often been replaced and show Staffelmauser patterns as in Definitive Basic Plumage, but some birds appear to retain some juvenile secondaries among s3-s4 and s9-s16 surrounded by three or more generations of basic feathers. By these cycles, precise determination of plumages is often not determinable due to individual variation in plumage maturation and molt rates, and it is possible that slower maturing individuals can show these head-plumage features (albeit with all juvenile remiges replaced) into the seventh or later predefinitive cycles.

Definitive Basic Plumage

Present primarily November (when fresh) to August (when worn). Crown and sides of head whitish or pale gray-brown. There is a black-brown ring of feathering around eye, which continues towards the foreneck and throat, which are bordered by filamentous gray-brown feathers on both sides of the crop. Body and upperwing coverts dark brown, the mantle with whitish, yellowish or pale gray erectile feathers on the upper sides, and the undertail coverts pale gray. The tail is black. Flight feathers and underwing coverts black with their outer edges brown or purple-bronze. Some individuals have some white bases of feathers visible among on the underwing and/or upperwing coverts (18 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 ).

Incomplete and/or protracted molts result in mixed generations or levels of wear among body feathers and upperwing coverts producing a mottled appearance that differs from the uniform feathering of Juvenile Plumage. Remiges typically show 2‒4 sets of basic feathers in Staffelmauser (or stepwise) patterns (see Molts), the number of sets signifying minimum age as in other large raptors (12 de la Puente, J., and J. Elorriaga (2012). Primary moult and its application to ageing in the Black Vulture Aegypius monachus. In The Black Vulture: Status, Conservation and Studies. Proceedings of the First International Symposium on the Black Vulture Aegypius monachus (Cordoba, Spain, 21–23 October 2004) (P. M. Dobado and R. Arenas, Editors), Consejería de Medio Ambiente, Junta de Andalucía, Córdoba, Spain. pp. 259–269. Close ; see also 3 Forsman, D. (2016). Flight Identification of Raptors of Europe, North Africa and the Middle East. Bloomsbury, London, UK. Close , 19 Pyle, P. (2005). Remigial molt patterns in North American Falconiformes as related to age, sex, breeding status, and life-history strategies. Condor 107(4):823–834. Close , 20 Pyle, P. (2006). Staffelmauser and other adaptive strategies for wing molt in larger birds. Western Birds 37:179–185. Close , 13 Zuberogoitia, I., J. De La Puente, J. Elorriaga, R. Alonso, L. E. Palomares, and J. E. Martínez (2013). The flight feather molt of Griffon vultures (Gyps fulvus) and associated biological consequences. Journal of Raptor Research 47(3): 292–303. Close ). See also Bare Parts for color changes in the bill, iris, and legs and feet by age.

General

Molt and plumage terminology follows Humphrey and Parkes (21 Humphrey, P. S., and K. C. Parkes (1959). An approach to the study of molts and plumages. Auk 76(1):1–31. Close ), as modified by Howell et al. (22 Howell, S. N. G., C. Corben, P. Pyle, and D. I. Rogers (2003). The first basic problem: a review of molt and plumage homologies. Condor 105:635–653. Close ). Under this nomenclature, terminology is based on evolution of molts along ancestral lineages of birds from ecdysis (molts) of reptiles, rather than on molts relative to breeding season, location, or time of the year, the latter generally referred to as “life-cycle” molt terminology (23 Jenni, L., and R. Winkler (2020). Moult and Ageing of European Passerines. Second edition. Bloomsbury, London, UK. Close ; see also 24 Pyle, P. (2022). Defining moults in migratory birds: a sequence-based approach. Journal of Avian Biology 2022(5):e02958. Close ). In north-temperate latitudes and among passerines, the Humphrey-Parkes (H-P) and life-cycle nomenclatures correspond to some extent but terms are not synonyms due to the differing bases of definition. Prebasic molts often correspond to “post-breeding“ or “post-nuptial“ molts (the Second Prebasic Molt often equating to the "first post-breeding molt," etc.) and preformative molts often correspond to “post-juvenile“ molts. The terms prejuvenile molt and juvenile plumage are preserved under H-P terminology (considered synonyms of first prebasic molt and first basic plumage, respectively) and the former terms do correspond with those in life-cycle terminology.

As in other large Accipitrine hawks, Cinereous Vulture appears to exhibit a Complex Basic Strategy (cf. 22 Howell, S. N. G., C. Corben, P. Pyle, and D. I. Rogers (2003). The first basic problem: a review of molt and plumage homologies. Condor 105:635–653. Close , 25 Howell, S. N. G. (2010). Molt in North American Birds. Houghton Mifflin Harcourt, Boston, MA and New York, NY, USA. Close ), including incomplete prebasic molts and perhaps a limited preformative molt (17 Pyle, P. (2005). First-cycle molts in North American Falconiformes. Journal of Raptor Research 39(4):378–385. Close ), but no prealternate molts (2 Cramp, S., and K. E. L. Simmons, Editors (1980). The Birds of the Western Palearctic. Volume 2. Hawks to Bustards. Oxford University Press, Oxford, UK. Close , 3 Forsman, D. (2016). Flight Identification of Raptors of Europe, North Africa and the Middle East. Bloomsbury, London, UK. Close , 13 Zuberogoitia, I., J. De La Puente, J. Elorriaga, R. Alonso, L. E. Palomares, and J. E. Martínez (2013). The flight feather molt of Griffon vultures (Gyps fulvus) and associated biological consequences. Journal of Raptor Research 47(3): 292–303. Close , 14 Pyle, P. (2008). Identification Guide to North American Birds, Part II: Anatidae to Alcidae. Slate Creek Press, Point Reyes Station, California, USA. Close ).

Prejuvenile (First Prebasic) Molt

Complete, primarily May–August, in the nest. Natal down is molted at 18‒25 days of age (16 Bernis, F. (1966). El Buitre negro (Aegypius monachus) en Iberia. Ardeola 12(1):45–99. Close ). Otherwise, no detailed information on this molt in Cinereous Vulture.

Preformative Molt

Only recently recognized in Acciptrine hawks as separate from commencement of the Second Prebasic Molt (17 Pyle, P. (2005). First-cycle molts in North American Falconiformes. Journal of Raptor Research 39(4):378–385. Close ); in Cinereous Vulture, this molt has not been confirmed (13 Zuberogoitia, I., J. De La Puente, J. Elorriaga, R. Alonso, L. E. Palomares, and J. E. Martínez (2013). The flight feather molt of Griffon vultures (Gyps fulvus) and associated biological consequences. Journal of Raptor Research 47(3): 292–303. Close ), but a limited molt may occur in some (but not all) individuals in November–March (cf. 9 Cramp, S., and K. E. L. Simmons, Editors (1980). The Birds of the Western Palearctic. Volume 2: Hawks to Bustards. Oxford University Press, Oxford, UK. Close ) as occurs in other large Accipitrine hawks (17 Pyle, P. (2005). First-cycle molts in North American Falconiformes. Journal of Raptor Research 39(4):378–385. Close , 14 Pyle, P. (2008). Identification Guide to North American Birds, Part II: Anatidae to Alcidae. Slate Creek Press, Point Reyes Station, California, USA. Close ). In those species, the Preformative Molt can include up to 40% of body feathers but can be absent in some individuals; based on examination of Macaulay Library images it appears to occur to a limited extent in Cinereous Vulture (see images under Formative Plumage). No wing coverts (probably) or flight feathers are replaced during Preformative Molts as in large Accipitrine hawks (but see right-hand image under Formative Plumage).

Second through Fourth Prebasic Molts

Incomplete, primarily May/June and November (12 de la Puente, J., and J. Elorriaga (2012). Primary moult and its application to ageing in the Black Vulture Aegypius monachus. In The Black Vulture: Status, Conservation and Studies. Proceedings of the First International Symposium on the Black Vulture Aegypius monachus (Cordoba, Spain, 21–23 October 2004) (P. M. Dobado and R. Arenas, Editors), Consejería de Medio Ambiente, Junta de Andalucía, Córdoba, Spain. pp. 259–269. Close ). Replacement of juvenile body feathers and upperwing coverts often incomplete, resulting in mixed juvenile and basic feathers in second and perhaps sometimes third basic plumage. Sequence of flight-feather replacement as in definitive prebasic molt. The juvenile primaries may often not all be replaced until the fifth or sixth calendar year, with only 2‒4 primaries replaced per year (12 de la Puente, J., and J. Elorriaga (2012). Primary moult and its application to ageing in the Black Vulture Aegypius monachus. In The Black Vulture: Status, Conservation and Studies. Proceedings of the First International Symposium on the Black Vulture Aegypius monachus (Cordoba, Spain, 21–23 October 2004) (P. M. Dobado and R. Arenas, Editors), Consejería de Medio Ambiente, Junta de Andalucía, Córdoba, Spain. pp. 259–269. Close ). Following the second and third prebasic molt, the outer 3–6 (often 4–5) juvenile primaries and corresponding primary coverts and 12–20 juvenile secondaries may often be retained, replaced secondaries usually being among the tertials, s1, s5, and perhaps s12 (12 de la Puente, J., and J. Elorriaga (2012). Primary moult and its application to ageing in the Black Vulture Aegypius monachus. In The Black Vulture: Status, Conservation and Studies. Proceedings of the First International Symposium on the Black Vulture Aegypius monachus (Cordoba, Spain, 21–23 October 2004) (P. M. Dobado and R. Arenas, Editors), Consejería de Medio Ambiente, Junta de Andalucía, Córdoba, Spain. pp. 259–269. Close , 13 Zuberogoitia, I., J. De La Puente, J. Elorriaga, R. Alonso, L. E. Palomares, and J. E. Martínez (2013). The flight feather molt of Griffon vultures (Gyps fulvus) and associated biological consequences. Journal of Raptor Research 47(3): 292–303. Close ). Staffelmauser (stepwise) replacement patterns (26 Stresemann, E., and V. Stresemann (1966). Die Mauser der Vögel. Journal für Ornithologie 107, Sonderheft. Close , 19 Pyle, P. (2005). Remigial molt patterns in North American Falconiformes as related to age, sex, breeding status, and life-history strategies. Condor 107(4):823–834. Close , 20 Pyle, P. (2006). Staffelmauser and other adaptive strategies for wing molt in larger birds. Western Birds 37:179–185. Close , 14 Pyle, P. (2008). Identification Guide to North American Birds, Part II: Anatidae to Alcidae. Slate Creek Press, Point Reyes Station, California, USA. Close ) ensue (see below), the third and fourth prebasic molts commencing where second and third prebasic molts arrested, respectively, with new sequences sometimes commencing at p1 and the tertials (see images under Plumages). During these initial remigial molts, symmetry is usually maintained between the wings but patterns can begin to become asymmetrical following the third or fourth prebasic molts.

Definitive Prebasic Molt

Incomplete, primarily between April and October/November; older birds may molt at a faster rate than younger birds (3 Forsman, D. (2016). Flight Identification of Raptors of Europe, North Africa and the Middle East. Bloomsbury, London, UK. Close ) and non-breeding birds typically molt more feathers than breeding adults (14 Pyle, P. (2008). Identification Guide to North American Birds, Part II: Anatidae to Alcidae. Slate Creek Press, Point Reyes Station, California, USA. Close ). Most to many body feathers, upperwing coverts, and rectrices are usually replaced every year, but many feathers may be retained; primaries and secondaries are only partially replaced every year. Primaries are replaced distally (p1 to p10), secondaries replaced proximally from s1, s5, and perhaps s12, and distally from the tertials (often bilaterally from the middle tertial, t2) , and rectrices may typically be replaced in sequence r1–r6–r3–r4–r2–r5 on each side of tail. Replacement among s10-s20 may be irregular or involved skipped feathers (cf. 27 Edwards, A. E. and S. Rohwer. (2005). Large-scale patterns of molt activation in the flight feathers of two Albatross species. Condor 107 (4):835-848. Close ), with consistent nodes possibly being maintained at s12 and s15 (cf. 13 Zuberogoitia, I., J. De La Puente, J. Elorriaga, R. Alonso, L. E. Palomares, and J. E. Martínez (2013). The flight feather molt of Griffon vultures (Gyps fulvus) and associated biological consequences. Journal of Raptor Research 47(3): 292–303. Close ), but more study is needed.

Molting patterns among primaries and secondaries exhibit Staffelmauser (26 Stresemann, E., and V. Stresemann (1966). Die Mauser der Vögel. Journal für Ornithologie 107, Sonderheft. Close , 28 Clark, W. S., R. D. Chancellor, and B. U. Meyburg (2004). Wave moult of the primaries in accipitrid raptors, and its use in ageing immatures. In Raptors Worldwide: Proceedings of the VI World Conference on Birds of Prey and Owls (R. D. Chancellor and B. U. Meyersburg, Editors). World Working Group on Birds of Prey, Budapest, Hungary. pp. 795–804. Close , 19 Pyle, P. (2005). Remigial molt patterns in North American Falconiformes as related to age, sex, breeding status, and life-history strategies. Condor 107(4):823–834. Close , 20 Pyle, P. (2006). Staffelmauser and other adaptive strategies for wing molt in larger birds. Western Birds 37:179–185. Close , 14 Pyle, P. (2008). Identification Guide to North American Birds, Part II: Anatidae to Alcidae. Slate Creek Press, Point Reyes Station, California, USA. Close ) whereby incomplete molts result is a series of commencement points, beginning with termination points of previous prebasic molt and also initiating new series commencing at p1, s1, s5, perhaps s12, and/or the tertials. Replacement thus typically proceeds in 2–4 (rarely 1 or 5) waves through the wing. After several years replacement patterns can become quite asymmetrical betwen the wings. Staffelmauser appears to be a product of insufficient time to undergo a complete wing-feather molt but has adaptive benefits in producing multiple small gaps in the wing during molt, which retains wing integrity and ability to fly and forage (29 Tucker, V. A. (1991). The effect of molting on the gliding performance of a Harris' Hawk (Parabuteo unicinctus). Auk 108:108–113. Close , 30 Shugart, G. W., and S. Rohwer (1996). Serial descendant primary molt or Staffelmauser in Black-crowned Night-Herons. Condor 98:222–233. Close , 19 Pyle, P. (2005). Remigial molt patterns in North American Falconiformes as related to age, sex, breeding status, and life-history strategies. Condor 107(4):823–834. Close ).

Bill and Cere

In nestlings, the maxilla is blackish at the tip and the mandible has a dark horn-colored tip up to 18 days of age; at 34 days old, the bill is black with a horn-colored basal area (16 Bernis, F. (1966). El Buitre negro (Aegypius monachus) en Iberia. Ardeola 12(1):45–99. Close ). In nestlings, the cere is pinkish white with a pale blue tinge up to 18 days of age; at 34 days old, it is pale pink with a darker pink commissural region; at 40‒43 days old it is whitish pink (16 Bernis, F. (1966). El Buitre negro (Aegypius monachus) en Iberia. Ardeola 12(1):45–99. Close ). The bill gradually darkens and the cere gradually changes to pinkish blue during the first 1–3 years of age. In adults, the maxilla is black with gray, brown, or yellow at the bases of the maxilla and mandible and the cere can be pale mauve, salmon-pink, or bluish white, tinged pale violet or violet-pink (1 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 , 2 Cramp, S., and K. E. L. Simmons, Editors (1980). The Birds of the Western Palearctic. Volume 2. Hawks to Bustards. Oxford University Press, Oxford, UK. Close ).

Head and Neck

In nestlings, the body skin is pink with a pale bluish tinge and flesh-pink color on the bald neck spot during the first 18 days of life; at 34 days of age, it has yellowish-white ventral skin, ivory-white on the neck with a slight pinkish tinge, and bluish-white areas without feathers on the face and chin; the periocular ridge is pink; at 40‒43 days, the neck is whitish pink, skin in the lacrimal and atrio-ocular areas more bluish; when the primaries are 14‒16 cm long, the lacrimal and auriculo-ocular areas are clearly bluish, still with a whitish-pink neck (16 Bernis, F. (1966). El Buitre negro (Aegypius monachus) en Iberia. Ardeola 12(1):45–99. Close ).

Iris

In nestlings the iris is lead-gray (18 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 ) or blackish with a dark brown tinge during first 18 days of life; at 34 days old nestlings have the iris blackish brown with a steel-gray tinge, which becomes black or blackish at 40‒43 days old (16 Bernis, F. (1966). El Buitre negro (Aegypius monachus) en Iberia. Ardeola 12(1):45–99. Close ). In juveniles the iris is dark brown or red-brown with yellow tinge, and in adults it is hazel, golden-brown, or deep red-brown (18 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 ).

Tarsi and Toes

The legs and feet are whitish pink with a slight light tint in nestlings up to 18 days of age; at 34 days old ivory-white with just a slight pink tinge; at 40‒43 days old pale pinkish, with a tendency to yellowish; in chicks of unknown age, with primaries of 14–16 cm long, the feet are pale pink, and on fledging the tarsi are pink (16 Bernis, F. (1966). El Buitre negro (Aegypius monachus) en Iberia. Ardeola 12(1):45–99. Close ). In juveniles the legs and feet are gray, dull yellow, or dull flesh (2 Cramp, S., and K. E. L. Simmons, Editors (1980). The Birds of the Western Palearctic. Volume 2. Hawks to Bustards. Oxford University Press, Oxford, UK. Close ), and in adults they and white with pink to cream or pale blue tones (1 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 , 2 Cramp, S., and K. E. L. Simmons, Editors (1980). The Birds of the Western Palearctic. Volume 2. Hawks to Bustards. Oxford University Press, Oxford, UK. Close ). The claws are blackish with a bright tip in nestlings up to 18 days old; from 34 days of age the claws are black or can become slate in adults (16 Bernis, F. (1966). El Buitre negro (Aegypius monachus) en Iberia. Ardeola 12(1):45–99. Close , 1 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 ).

Linear Measurements

There is a tendency for the female Cinereous Vulture to be larger and have a greater body mass than males, but the sample size of measured birds is small (1 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 , 2 Cramp, S., and K. E. L. Simmons, Editors (1980). The Birds of the Western Palearctic. Volume 2. Hawks to Bustards. Oxford University Press, Oxford, UK. Close ).

Overall Length

Males (Romania) 102–107 cm (n = 20) (18 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 ).

Females (Romania) 104–112 cm (n = 21) (18 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 ).

Wing Length

Males (Romania) 740–780 mm (n = 20) (18 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 ).

Males (southern Europe) 740–820 mm (mean 776 mm, n = 12) (1 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 ).

Males (southern Europe, Morocco, and Türkiye) 720–735 mm (mean 772 mm, n = 10) (2 Cramp, S., and K. E. L. Simmons, Editors (1980). The Birds of the Western Palearctic. Volume 2. Hawks to Bustards. Oxford University Press, Oxford, UK. Close ).

Females (Romania) 750–830 mm (n = 21) (18 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 ).

Females (southern Europe) 765–828 mm (mean 795 mm, n = 7) (1 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 ).

Females (southern Europe, Morocco, and Türkiye) 750–845 mm (mean 801 mm, n = 4) (2 Cramp, S., and K. E. L. Simmons, Editors (1980). The Birds of the Western Palearctic. Volume 2. Hawks to Bustards. Oxford University Press, Oxford, UK. Close ).

Both sexes (Spain) 740–812 mm (mean 780 mm, n = 9) (1 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 ).

Both sexes (Balkans, Urals, and Caucasus) 740–834 mm (mean 783 mm, n = 18) (1 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 ).

Both sexes (Kyrgyzstan) 725–870 mm (n = 14) (1 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 ).

Both sexes (Turkmenistan) 770–850 mm (n = 13) (1 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 ).

Both sexes (China) 801–887 mm (n = 9) (1 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 ).

Wingspan

Both sexes 250–295 cm (2 Cramp, S., and K. E. L. Simmons, Editors (1980). The Birds of the Western Palearctic. Volume 2. Hawks to Bustards. Oxford University Press, Oxford, UK. Close ).

Tail length

Males (Romania) 335–402 mm (n = 20) (18 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 ).

Males (southern Europe, Morocco, and Türkiye) 330–410 mm (mean 365 mm, n = 8) (2 Cramp, S., and K. E. L. Simmons, Editors (1980). The Birds of the Western Palearctic. Volume 2. Hawks to Bustards. Oxford University Press, Oxford, UK. Close ).

Females (Romania) 330–405 mm (n = 21) (18 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 ).

Females (southern Europe, Morocco, and Türkiye) 330–410 mm (mean 381 mm, n = 4) (2 Cramp, S., and K. E. L. Simmons, Editors (1980). The Birds of the Western Palearctic. Volume 2. Hawks to Bustards. Oxford University Press, Oxford, UK. Close ).

Bill Length

Males (southern Europe, Morocco, and Türkiye) 60–64 mm (mean 61.6 mm, n = 8) (2 Cramp, S., and K. E. L. Simmons, Editors (1980). The Birds of the Western Palearctic. Volume 2. Hawks to Bustards. Oxford University Press, Oxford, UK. Close ).

Females (southern Europe, Morocco, and Türkiye) 58–64 mm (mean 60.8 mm, n = 4) (2 Cramp, S., and K. E. L. Simmons, Editors (1980). The Birds of the Western Palearctic. Volume 2. Hawks to Bustards. Oxford University Press, Oxford, UK. Close ).

Tarsus Length

Males (southern Europe, Morocco, and Türkiye) 120–143 mm (mean 129 mm, n = 9) (2 Cramp, S., and K. E. L. Simmons, Editors (1980). The Birds of the Western Palearctic. Volume 2. Hawks to Bustards. Oxford University Press, Oxford, UK. Close ).

Females (southern Europe, Morocco, and Türkiye) 124–138 mm (mean 132 mm, n = 4) (2 Cramp, S., and K. E. L. Simmons, Editors (1980). The Birds of the Western Palearctic. Volume 2. Hawks to Bustards. Oxford University Press, Oxford, UK. Close ).

Mass

Males (Romania) 7.0–11.5 kg (n = 20) (18 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 ).

Females (Romania) 7.5–12.5 kg (n = 21) (18 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 ).