The Slender-billed Vulture is an Old World Vulture from the Gyps genus. A long and slender bill gave the vulture its name. With wingspans mearuring between 234-260 cm this is one of the larger vulture species.
The Slender-billed Vulture is a native to the Indian subcontinent and distributed in lower Himalaya, Pakistan, North India, Nepal, Bhutan, Burma, Thailand, Malaysian peninsular and south Laos.
Until the early 1990s this species was one of the most common vultures in the countryside and urban areas and metropolitan cities. They used to gather in their hundreds on squares and near slautherhouses, and were by no means afraid of mankind. Despite their dark appearance, society accepted them as vital for the disposal and processing of carcases, carrion and human corpses. Unfortunately, in our days they have come close to extinction.
Species: Slender-billed Vulture
Scientific Name: Gyps tenuirostris
Name in German: Dünnschnabelgeier
Name in French: Vautour à long bec
Name in Dutch: Dunsnavelgier
Name in Italienisch: Grifone beccosottile
Name in Finnish: Gangesinkorppikotka
Name in Danish: Smalnäbbad gam
Name in Swedish: Smalnäbbad gam
Name in Polish: Sęp bengalski
Name in Nepali: सानो खैरो गिद्ध
Name in Bengali: সরুঠুঁটি শকুন
Name in Malaysian: Burung Hereng Paruh Panjang
Name in Thai: อีแร้งสีน้ำตาล, อีแร้งสีน้ำตาลหัวดำ, อีแร้งสีน้ำตาลหิมาลัยgam
Name in Chinese: 细嘴兀鹫
Name in Chinese (traditional): 細嘴兀鷲
Name in Russian: Тонкоклювый сип
Distribution: Indomalayan. Distribution area covers Pakistan, Nepal, Bhutan, north and east of Burmaa, Cambodia, south Laos, Malaysia, Thailand, the northwest of India towards the Assam.
Movements: Sedentary. Food shortages may lead to evasive movements in order to survive. Immature Slender-billed Vultures are nomadic.
Habitat: wetlands and wooded areas. also near settlements, open countryside. Settles also in lower mountain range in altitudes of up to 1,000 m; also sub-himalayan ranges.
Behaviour: Very good at gliding. Processes carcases, always away on search flights to find new food. Glides up to altitudes of 1,500 m. At feeding places Slender-billed Vultures mostly appear in small groups and socialises with Lappet-faced Vultures and White-rumped Vulture, though they give way to the latter ones. The pecking order at carcases is as follows: Lappet-faced Vulture – White-rumped Vulture – Slender-billed Vulture. Regular guest at landfills and slaughterhouses.
Size: 93-100 cm
Tail: 24-26 cm
Weight: 4,000-7,000 g
Wingspan: 234-250 cm
Wing: 590-607 mm
Sexually mature: probably in the 5th year, simulatenously with moulting into the adult plumage.
Voice: schnarrende und grunzende Laute, vor allem beim Fressen werden grunzende Laute geäußert.
Mating: Mating starts prior to courtship and subsequent breeding as early as October.
Clutches per breeding season1 clutch
Breeding: as early as October, mostly between December and January, Burma from October
Nest: Large platform from sticks and branches, decorated and lined with twigs, fresh and fresh green. Nest stands on large trees, usual in heights between 7-15 m, also on ledges.
Clutch: 1 egg
Eggs: egg with white shell and reddish staints and speckles
Egg Measurements and Weights
Length x Width: 92.5x69.3 mm
Weight: ≈ ??? g
Recurrent Clutches: not porbable.
Incubation: 50 days; ♂ and ♀ share the task of incubation
Fledging: Chicken is fed by both parents. There are no firm data with regard to fledging, though a period of 80-90 days can be assumed.
Dependency: As is customary wih Gyps vultures, the young Slender-billed Vulture will be dependent on ist parents for feeding and education at least for several weeks. Though, there are no firm data existing.
Food: The Slender-billed Vulture fully depends on the abundance of carrion. Carcases of cattle, all sorts of fallen game, human corpses, also dead cattle after outbreaks of cattles diseases. In India the Slender-billed Vulture once played a central role as the processer and disposer of human corpses, and carcases, which was accepted and expected by natives. These vultures also used to populate landfills and slaughterhouses.
Threats: Main threats are targeted poisoning, persecution in Laos, loss of food in Cambodia, deforestation in Nepal. By early 2000 the Slender-billed Vulture also fell victim to the painkiller Diclofenac which was use in veterinary medicine. By consuming dead cattle that previously had been treated with Diclofenac, the vultures suffered and died from instant multiple organ failure. Within a short period the population crashed by devastating 97%.
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Ferguson-Lees, James and Christie, David A., Raptors of the World, Houghton Mifflin Company Boston New York, 2001
Ferguson-Lees, James, Christie, David, Raptors of the World, A Field Guide, Christopher Helm London, 2005, reprinted 2019
Fischer, Wolfgang, Die Geier, Die Neue Brehm-Bücherei, A. Ziemsen Verlag Lutherstadt Wittenberg, 1963
Grzimek, Bernhard et al (HG), Grzimeks Tierleben, Band VII, Vögel 1, Kindler Verlag AG Zürich, 1968
Weick, Friedhelm, Die Greifvögel der Welt, Verlag Paul Parey Hamburg und Berlin, 1980
Slender-billed Vulture - source: neil bowman/agency iStock