The Palmnut Vulture is a vulture and monotypical to the Gypohierax genus. As a vulture it comes across as rather smallish, sized only between 57-65 in length and a wingspan of only 133-155.
Acutally, size is noth the only thing making this vulture the odd one out. The reason for being special simply is its diet. This vulture mostly feeds on the fruits of the palm oil tree and only to a much lesser degree on fish, crabs and amphibians. Though it does not feed on carcases or carrion as the larger vultures usually do.
Taxonomy:
Order: Accipitriformes
Family: Accipitridae
Genus: Gypohierax
Species: Palmnut Vulture
Scientific Name: Gypohierax angolensis
Name in German: Palmgeier
Name in French: Palmiste africain
Name in Dutch: Palmgier
Name in Spanish: Buitre Palmero
Name in Italian: Avvoltoio delle palme
Name in Finnish: Palmukorppikotka
Name in Danish: Palmgrib
Name in Swedish: Palmgam
Name in Polish: Palmojad
Name in Russian: Пальмовый гриф
Distribution: Afrotropical, locally abundant from West Africa to Angola. In Sub-Saharan Africa: Senegal and Gambia (Senegambia) to south Mali, central Nigera and southernmost Chad, from Sudan southwards to Angola, Zambia, Mozambique; extreme northeastern South Africa (Zululand); east Kenya and northeast Tanzania, Pemba and Zanzibar.
Movements: Always moves to rich food grounds, otherwise adults are sedentary. Immature are nomadic
Habitat: Forests, tall woodland, mixed forest, cultivation of oil and raffia palms; streams, rivers, lakes, oil-palm plantations. Requires waterside natural forests to breed. Also in wooded savannah without direct access to water. Does not approach larger settlements but allows humans to approach closely. Up to sealevels of 1,500 m.
Behaviour: Mostly feeding directly from palm oil trees, otherwise search flights to find food.
Size: 57-65 cm
Tail: 19-21 cm
Weight: 1700-1900 (max. 2100) g
Wingspan: 133-155 cm
Wing: 390-461 mm
Voice: Generally silent, utters low growls when feeding and duck-like quacking at roost; hisses, whistling and barking.
Sexually Mature: probably in the 4th year, when changing into adult plumage.
Mating: Coincides with courtship and nest building.
Clutches per breeding season1 clutch
Breeding: in Nigeria schon ab Januar bis April
Brutzeit: Januar bis August; teilweise auch zwischen Juli und November.
Nest: Nest made from sticks, lined with green leave and palm fronds. Sits mostly on side branches in trees, mostly palm trees.
Clutch: 1 egg
Egg: White elliptical egg mostly covered with darkish staints.
Egg Measurements and Weight
Length: 67.0-78,3 mm
Width: 52.0-57.0 mm
Ø Length x Width: 70.7x54.0 mm;
Gewicht: ≈ ??? g
Recurrent Clutch: unknown.
Breeding: ≃ 41-44 days
Fledging: chicken is fed by both parents; fledging after c. 90 days.
Dependency: After fledging the young Hooded Vulture returns for sleeping to nest for another 4 weeks.
Food: Fruit, fish, crabs, amphibians, invertebrates, small mammals, birds, reptiles, carrion. Eats fleshy parts of fruits of oil palms.
Longevity: unknown.
Mortality: unknown.
Threats: Stable population throughout most of Africa. Main threat is loss of habitat.
Brown, Leslie, Die Greifvögel, Ihre Biologie und Ökologie, Paul Parey Verlag Hamburg und Berlin, 1979
Ferguson-Lees, James, Christie, David, Raptors of the World, A Field Guide, Christopher Helm London, 2005, reprinted 2019
Ferguson-Lees, James & Christie, David, Raptors of the World, Houghton Mifflin Company Boston New York, 2001
Fischer, Wolfgang, Die Geier, Die Neue Brehm-Bücherei, A. Ziemsen Verlag Lutherstadt Wittenberg, 1963
Glutz von Blotzheim, Urs et. al (HG), Handbuch der Vögel Mitteleuropas, Band 4, Falconiformes, AULA-Verlag Wiesbaden, 2. durchgesehene Auflage 1989
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
Egg of the Palmut Vulture: by Didier Descouens - Eigenes Werk, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=16927677