Tahaweber
| Tahaweber | ||||||||||||
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Male of the Tahaweber |
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Euplectes afer | ||||||||||||
| ( Gmelin , 1758) |
The Taha weaver ( Euplectes afer ), also known as Napoleon weaver , is a species of songbird from the weaver bird family . It is widespread in many scattered sub-areas across sub-Saharan Africa and was introduced elsewhere. Outside of Africa, there are populations in the United States and the West Indies, as well as the Iberian Peninsula .
description
The Taha weaver is one of the small species of weaver bird and, with a body length of 10 cm, is roughly comparable in size to a blue tit. It weighs between 11 and 20 g. The tail is very short. The iris is brown. The sexes differ significantly during the breeding season - the male's magnificent dress is brightly colored black and yellow. In the plain dress, the male resembles the rather gray-brown female.
In adult males of the nominate form , the beak is black in the splendid dress. The forehead, crown and nape of the head are intensely golden yellow, the feathers of the back nape of the neck are pointed black. The sides of the head, chin and throat contrast black. A wide yellow chest band, which is tinted chestnut brown in the middle of the chest, merges into the yellow flanks. The posterior belly and the under tail-coverts are also yellow. The rest of the belly is black. The upper dorsal plumage is dark brown with yellow tip edges. The lower back and rump are yellow. Some upper tail ceilings are lined with black. Upper wing and control feathers are brown, with the wing covers wearing light brown seams. Legs and feet are brown.
In the case of females and males in a plain dress, the upper beak is dark and the lower beak is light brown. The forehead, crown, nape and upper side are brown with dark feather centers. From this stand out a light stripe above the eyes as well as a light area under the eye and the front beard stripe . The chin, throat, chest and stomach are whitish with dark lines on the flanks and on the chest, where they condense into a loose band. The under tail-coverts are whitish, the leg fletching is brown. Wing and rudder feathers are brown, with light colored seams on the upper wing coverts.
Birds in juvenile plumage are similar to females, but before juvenile moulting, they are characterized by broad yellowish-brown borders on all feathers.
Distribution and geographic variation
The distribution area of the Tahaweber stretches over all of Sub-Saharan Africa , but is highly fragmented. It consists of numerous distribution islands, some of which can be quite small.
Three subspecies are recognized. Another from southern Sudan ( E. a. Ladoensis ) is usually found in E. a. taha incorporated. The description of E. a. niassensis from southern Tanzania is based on a single female specimen and must be considered unsecured.
The subspecies E. a. strictus from the Ethiopian highlands is larger than the nominate form. In males in breeding dress, the yellow of the upper head only extends to the sides of the neck. The belly is completely black. The females are more yellowish-brown underneath and more strongly dashed than those of the other subspecies.
The males of E. a. taha from the southeastern part of the distribution are marked in the breeding dress by a black neck band. The underside is black from the throat to the lower abdomen. There is a mostly small yellow area on the chest and partly on the flanks.
- E. a. afer ( JF Gmelin , 1789) - southern Mauritania , Gambia , coastal regions of Senegal , Guinea-Bissau , Guinea and Sierra Leone , northeastern Ivory Coast , river basins of Mali , Burkina Faso , northern parts of Ghana , Togo and Benin , southwestern Niger , northern and central Nigeria , North, center and west of Cameroon , northern Central African Republic , western Sudan and Nile Valley , south to the Republic of the Congo along rivers, northern Democratic Republic of the Congo and western Angola . Very little evidence is available from Liberia , Chad , Gabon and Uganda .
- E. a. strictus Hartlaub , 1857 - plateaus in central Ethiopia.
- E. a. taha A. Smith , 1836 - southern Sudan, southern Somalia, western Kenya, central Tanzania, southeastern Democratic Republic of the Congo, southern Angola, southwestern and northern Zambia, northern Namibia, northern and eastern Botswana, western Zimbabwe , eastern South Africa and the lowlands from Lesotho . Occasional evidence from Swaziland and Mozambique .
Duration
The Taha weaver is not endangered and is regionally frequent in its natural range. The species was able to establish populations elsewhere as neozoon , which presumably go back mainly to captive refugees - for example in the USA, in Puerto Rico and Jamaica . A population in Hawaii is believed to have died out again.
In Europe, the species was first found breeding in 1989 in the rice fields of Lagoa in the Algarve . Since then, local populations have been able to establish themselves, some of which are growing in the stock. The largest are in the southern center of Faro , in the estuaries of the Tejo and Sado and in swamps or rice-growing areas near Santarém , Coimbra and Aveiro . The species has also been breeding in Spain since at least 2000. In addition to various records with suspected breeding, there is a growing population in the Guadalquivir estuary and in the rice fields of Brazo del Este near Seville . There are now likely to be several hundred breeding pairs there.
hikes
Little research has been carried out into the migration behavior of the Tahawebers. In South Africa the species seems to live nomadically and only form breeding colonies after heavy rainfall. In subsequent years there may be no breeding at all. There seem to be regular migrations in the Zambezi Valley , and observations of migrating specimens in Nigeria and Central Africa also suggest regular, longer migration routes.
habitat
The taha weaver inhabits open grasslands on the plains. Only in Ethiopia does the altitude range reach 1800 m. The species breeds in wetlands such as swamps and floodplains.
nutrition
The taha weaver feeds mainly on grass seeds. In Nigeria, these are predominantly those of sweet grasses of the genera Brachiaria , Cymbopogon , Dactyloctenium , Digitaria , Hyperthelia or Sporobolus , but also of sour grasses such as Cyperus dilatatus or Mariscus alternifolius . But also seeds of herbaceous plants such as Boerhavia species or the invasive species Tridax procumbens introduced into Africa . In Kenya, chicken millet , and in South Africa, panicle and bristle millet were found as food crops. In winter the food spectrum can be wider. Young maize, for example, is then also eaten.
In captivity, the species also accepts animal food such as insects and their larvae.
Reproduction
The Taha weaver is polygynous and breeds in small colonies, in which the males defend their territories with fluttering flights against other males and sometimes also females. The breeding season varies depending on the geographical location; north of the equator it is mostly between July and October, but in Ethiopia in October, south of the equator between January and July and in South Africa between December and March.
The nest is a round oval building with a side entrance in the upper half. It usually stands about one meter above the ground in flooded or waterlogged areas and is attached to vertical stalks. It is often found in the cover of bushes, tufts of grass, sedge or rushes. It is woven from thin strips of grass by the male and padded with fine grass by the female. Ears of wheat often protrude from the nest or the entrance.
The clutch consists of two to four eggs with fine, dark speckles on a white background, which often condense at the blunt pole. The eggs are about 18 × 13 mm in size. According to observations from captivity, the female incubates alone for 12 to 14 days. The male participates in raising the young. The nestling period is 13 days.
literature
- Adrian Craig: Yellow-crowned Bishop (Euplectes afer) (2010/2013), in: J. del Hoyo, A. Elliott, J. Sargatal, AD Christie, E. de Juana (eds.): Handbook of the Birds of the World Alive , Lynx Edicions, Barcelona 2014
Individual evidence
Unless otherwise stated, the information comes from the source given under "Literature".
- ↑ Eduardo de Juana, Ernest Garcia: The Birds of the Iberian Peninsula , Christopher Helm / Bloomsbury Publishing, London 2015, ISBN 9781472905918 , p. 576 f
Web links
- Euplectes afer onthe IUCN 2015-3 Red List of Threatened Species . Listed by: BirdLife International, 2012. Retrieved October 4, 2015.