Bald Bearded Bird

from Wikipedia, the free encyclopedia
Bald Bearded Bird
White-headed Barbet, Lake Manyara, Tanzania (8495910236) .jpg

Bald Bearded Bird ( Lybius leucocephalus )

Systematics
Class : Birds (aves)
Order : Woodpecker birds (Piciformes)
Family : African bearded birds (Lybiidae)
Genre : Toothbeard birds ( Lybius )
Type : Bald Bearded Bird
Scientific name
Lybius leucocephalus
( De Filippi , 1853)

The bald-headed bearded bird ( Lybius leucocephalus ) is a species from the African bearded bird family . The species occurs on both sides of the equator and has a disjoint distribution area. Several subspecies are distinguished. The IUCN classifies the white-headed bearded bird as not endangered ( least concern ).

Appearance

The males of the nominate form have a wing length of 8.8 to 9.5 centimeters. The beak is an average of 2.5 centimeters long. They usually weigh between 55 and 65 grams. Females have similar body measurements. There is no noticeable sexual dimorphism .

Star weaver , one of the few species of birds with which the white-headed bearded bird can be confused

Males and females have a white head, a white front back, and a white front chest. The back is black-brown, which gradually fades to a white at the end of the back. The rump and upper tail-coverts are white. The control springs are black on the top and brownish on the underside. The center of the chest is pale black, this also applies to the sides of the body and the flanks. The wings are black, the wings have white feather tips. The beak is black, the featherless skin around the eyes is gray to blackish gray, the eyes are brown. The legs and feet are gray to black. Young birds are generally more dull than adult birds. With them, the white parts of the body show individual gray to brown spots. Their beak is gray to dark horn-colored. The eyes are a paler brown than that of the adult birds.

There is a possibility of confusion with the star weaver . This bird, which belongs to the weaver birds , has an orange to red-orange rump. The fig-bearded bird , which occurs much further south of Africa, also has predominantly black and white plumage, but has a red spot on its forehead.

Distribution area

The white-headed bearded bird occurs in three regions in Africa. A distribution area extends from the northern half of Nigeria to the south of Chad and in a southerly direction to the north of Cameroon , the west of the Central African Republic and the north-west of the Democratic Republic of the Congo . A second distribution area extends from the northeast of the Democratic Republic of the Congo over the northeast of the Central African Republic to the south of Sudan and Uganda as well as Kenya and Tanzania . Whitebeard birds are isolated from this on the high plateau in the southwest of Angola . White-headed bearded birds are typically found at altitudes between 600 and 2,300 meters. In Kenya, however, they occasionally occur at sea level.

Way of life

The white-headed bearded bird is a very adaptable species. It inhabits open wooded areas, forests along rivers and even dry scrubland, provided that it has sufficiently fruit-bearing trees. It is also found in gardens and on cultivated land if these have trees. They can be observed almost without exception in groups of up to eight individuals.

Silky turaco occasionally chase bald bearded birds out of food trees

The food spectrum of the whitehead bearded birds mainly includes fruits and berries. They also eat termites and catch flying ants and termites in flight. Occasionally they also come to the ground to catch dung beetles . During feeding, they are somewhat less agile and adept than the beard birds of the genus Haarbärtlinge or black-collared barbet . Often they hold on to the branches in a way that seems awkward to humans and relatively often fruits also fall on the ground. They often come to the ground to pick these fruits. They are relatively aggressive birds that are more often chased away from fruit-bearing trees by the significantly larger silk turaco , but can also defend themselves vigorously. The smaller yellow-tufted dwarf beards and masked spirals are clearly inferior to the white-headed bearded birds . Troops of white-headed bearded birds manage to keep croissants away from the nesting cavity. Aggressive bald-headed bearded birds turn their beak towards their opponent, raise their plumage and spread their wings a little.

White-headed bearded birds are cave breeders. Obviously all members of a squad are involved in carving the cave. The members of the troop are probably a couple and the adult, not yet mated offspring from earlier clutches. They play a helper role in the territory and, for example, defend a nesting hole together with the parent bird against breeding parasites such as the little honey indicator . Typically, a member of the troop either remains directly in the brood cavity or at least in its vicinity.

The nest hole is usually five to twenty meters above the ground. Dead tree trunks or individual branches are used. Whilst the nesting hole is being chopped up, white-headed bearded birds do not leave it at the foot of the tree, but usually carry the chips to another place. The clutch consists of two to four eggs. The breeding season is 15 to 21 days. All adult birds in a flock are involved in the brood. Brood changes are very frequent and usually occur four to five times an hour. After hatching, both the parent birds and the helpers feed insects and fruits to the young birds. They bring in food up to 15 times an hour. Usually only two young birds fly out per clutch.

supporting documents

literature

  • Lester L. Short, Jennifer FM Horne: Toucans, Barbets and Honeyguides - Ramphastidae, Capitonidae and Indicatoridae. Oxford University Press, Oxford 2001, ISBN 0-19-854666-1 .

Individual evidence

  1. ↑ Short et al., P. 194.
  2. ↑ Short et al., P. 193.
  3. ↑ Short et al., Color plate 5
  4. ↑ Short et al., P. 195.
  5. ↑ Short et al., P. 197.

Web links