Bearded birds
| Bearded birds | ||||||||
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| Systematics | ||||||||
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| Scientific name | ||||||||
| Trachyphonus | ||||||||
| Ranzani , 1821 |
The bearded birds ( Trachyphonus ) are a genus from the African bearded bird family. They are relatively small bearded birds with showy yellow, white and black plumage. In contrast to African bearded birds of other genera, they stay relatively often on the ground. Duet singing occurs in all types. The utterances of the flamehead bearded bird are typical sounds of the East African savannah. The most northerly distribution is the pearl-bearded bird , which occurs exclusively north of the equator.
Bearded birds are sometimes common birds. The flameheaded bearded bird and the boned bearded bird become trusting of people where they are not hunted and sometimes also come to the villages to look for food. All five species are classified by the IUCN as not endangered ( least concern ).
Appearance
Bearded birds have a wing length between 8 and 10 centimeters. They weigh between 47 and a little more than 100 grams. The flamehead bearded bird has the lowest body weight with 47 to 62 grams. The sexual dimorphism is not very pronounced in any of the species. In the flamehead bearded bird, the females usually lack the black vertical stripe.
The black to black-brown top of the body is characteristic of bearded birds, which is either densely spotted with white or appears cross-banded in white because of the white feather tips. The rump is yellowish to white-yellowish. The nape of the neck is small speckled in all species, in most species the spots are dark, in the crested-whiskered bird also orange or red-orange.
All species have markings at the level of the ear opening. In the flamehead bearded bird and the pearl bearded bird, this is a crescent-shaped, white stripe. In the crested bearded bird and the earmarked bearded bird, the streak is dark, in the earmarked bearded bird it is sometimes only indistinctly recognizable due to the markings. All species have shades of red on either the under tail coverts or the upper tail coverts. The chest drawing is also typical. In four species a narrow black and white band runs across the middle of the chest. In the earmarked bearded bird and the pearly bearded bird this is not completely closed, it is most conspicuously developed in the flameheaded bearded bird. However, all species have black markings on the throat or front chest. This can be seen most clearly in the crested bearded bird, which has a large, shield-shaped spot on its front breast.
The tail is long in relation to body size in all species. It is cross-banded from white to yellowish-white, the narrowest cross-banded by the crested bearded bird. This species gets its German name from the eye-catching little black feather bonnet on the neck.
Distribution area
The distribution area of the bearded birds extends in Africa from latitude 20 degrees north to the southeast of the African continent. The crested bearded bird occurs farthest south. The flamehead bearded bird and the earmarked bearded bird live in East Africa. The distribution areas of the individual species partially overlap.
Way of life
Bearded birds are omnivores and eat a wide range of berries, seeds and fruits. In addition, earwigs, beetles, praying mantises, grasshoppers, termites, ants, spiders and small lizards play a role in their diet. Some species also eat the eggs and young birds of other bird species. The flame head is a very socially living bird that is mostly found in small associations. The crested bearded bird, on the other hand, lives mostly in pairs.
Bearded birds are cave breeders who make their own burrows in tree trunks or termite mounds. They are able to raise more than one brood per year. Infanticide has been proven in the crested bearded bird : In this species, it has been observed that the surviving bird mated again very quickly after losing its partner. In two observed cases, the new partner destroyed the eggs or killed the nestlings and then started the hatching business again.
species
The following five species are included in the bearded bird genus:
- Latticed bearded bird ( Trachyphonus darnaudii )
- Flamehead bearded bird ( Trachyphonus erythrocephalus )
- Perlbartvogel ( Trachyphonus margaritatus )
- Yellow-billed bearded bird ( Trachyphonus purpuratus )
- Crested bearded bird or black-backed bearded bird ( Trachyphonus vaillantii )
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
