Brown-backed gold sparrow
| Brown-backed gold sparrow | ||||||||||||
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Brown-backed gold sparrows, Sudan |
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| Scientific name | ||||||||||||
| Passer luteus | ||||||||||||
| ( Lichtenstein , 1823) |
The brown-backed gold sparrow ( Passer luteus ) is a species of bird in the sparrow family. It is one of the few sparrow species that are kept relatively often as ornamental birds in Europe.
The brown back gold sparrow is classified by the IUCN as 
(= least concern - not endangered).
description
The brown-backed gold sparrow reaches a body length of 12 to 13 centimeters. The male has a golden yellow plumage with a chestnut brown back and tail. During the breeding season the beak is black, otherwise it is flesh-colored like the feet and legs. The female of the brown-backed gold sparrow is sandy brown, with the underside of the body being slightly lighter than the upper side. Its sounds are reminiscent of those of the house sparrow .
The males of the brown-backed gold sparrow are unmistakable in their magnificent dress. The Yemen gold sparrow , with which the brown-backed gold sparrow forms a superspecies , has darker plumage and does not show any brown. The female shows similarities with the females of the house sparrow and the chestnut sparrow , but their plumage is yellowish. It differs from the females of the Yemen gold sparrow in the sandy-brown top of the body and the longitudinal stripes on the coat.
distribution
The distribution area of the brown-backed gold sparrow extends from Mali in West Africa to East African Ethiopia and Sudan and is between 12 ° and 20 ° N. Brown-backed gold sparrows are predominantly nomadic and breed opportunistically when the habitat conditions give them the opportunity. In Senegal and Mauritania the distribution area does not extend further south than the 500 mm isohyete , in the north the distribution limit is around the 250 mm isohyete. In years with high rainfall, however, the brown-backed gold sparrows breed in regions that normally have only 100 mm of precipitation per year. Since the 1960s, the increasing irrigation measures have presumably meant that the brown-backed gold sparrow was able to expand its breeding area.
habitat
The habitats of the brown back gold sparrow are arid , sandy savannahs, which are loosely covered with thorn bushes and trees, as well as dry forest regions. It is not a pronounced cultural follower, but occasionally looks for food in grain fields and village gardens. Brown-backed gold sparrows prefer to breed in regions that either have permanent water points or where irrigation measures give them access to water. In Senegal and Mauritania, the brown-backed gold sparrow occurs in regions with an average annual temperature of 29 to 30 degrees. In Eritrea it is often found in savannas sparsely overgrown with acacias at altitudes below 1200 meters. He also inhabits the coastal plain here. In Sudan it breeds in the coastal region of the Red Sea and avoids mountainous regions. The brown-backed gold sparrow has also developed human settlements as a habitat and occurs in fields and in localities.
Way of life
Outside the breeding season, the brown-backed gold sparrow is a very sociable species. It can then be observed almost always in loose groups of 10 to 100 individuals. Occasionally, however, such troops can contain up to 10,000 individuals. The brown-backed gold sparrow is often associated with the bloodbeak weaver, weaver birds of the genera Bubalornis or Ploceus , the willow sparrow , the bandamadine , the African silver beak or other splendid finches . In general, it is a shy bird that flies up quickly when people approach it. Comfort behavior includes extensive dust baths as well as bathing in water.
At the beginning of the dry season, when food is still sufficiently and widely available, there are always only a few birds at individual resting places, the location of which is constantly shifting. Towards the end of the dry season, large communal resting places form near watering points and feeding grounds. At such a resting place in Senegal there were 400,000 brown-backed gold sparrows spread over an area of 20 hectares. In Niger, more than a million individuals of this species of sparrow gathered over an area of 800 hectares during the night. As a rule, dense thorn bushes, trees and sugar cane fields are chosen as resting places. Some resting places are visited again and again outside of the breeding season over a period of five months. Brown-backed gold sparrows leave the resting place at dawn. They are only active all day in rainy weather and during the breeding season. Outside of the breeding season, they rest during the hottest part of the day in trees and bushes not far from their feeding grounds. If the temperature drops around 4 p.m., they go to the watering holes to bathe and drink. They fall into their nocturnal resting places 60 to 90 minutes before sunset.
Foraging and Food
Brown-backed gold sparrows look for their food mainly on the ground, they prefer to stay near trees and bushes, which they visit again to rest between the individual phases of activity. During the breeding season, they mostly look for food individually and then do not move too far from the nesting tree. Troops of eating brown-backed gold sparrows are generally aligned in one direction, the birds in the back regularly fly over the birds in front in order to sit at the head of the troop. Seed is both picked from the ears and picked up from the ground.
The diet consists mainly of grass seeds such as those of millet and agricultural crops such as pearl millet , rice and sorghum . The birds also eat fruits, tomatoes, flowers, insects, spiders and snails. The nestlings are fed with large insects and their larvae.
Reproduction
Brown-backed gold sparrows nest almost exclusively in breeding colonies, which can be very large. In Senegal 1,000 to 20,000 nests per square kilometer, in Mali 10,000 and Niger between 12,000 and 57,000 nests per square kilometer were counted. There can be up to 15 nests in a single tree. Only the immediate vicinity of the nest is defended by the breeding pairs. The brown-backed gold sparrow is monogamous, but it is not yet certain whether the relationship will last longer than one breeding period.
Brown-backed gold sparrows are opportunistic breeders. They start breeding when the ground is covered with young vegetation after rainfall and there are enough insects to feed the young birds and watering holes. The breeding business is not synchronized within the colony; the breeding colony can exist for up to two months with breeding pairs in different stages of the breeding business. The nest is a ball nest with a side entrance. It is not built very carefully, the nesting material that has not been worked on on the outside usually hangs loosely. Brown-backed gold sparrows obstruct grass, bark, leaves, flowers and feathers, among other things. The nest is usually in a fork of branches, 1.8 to 5.0 meters above the ground. The nest building is initiated by the male, who either picks up twigs from the ground or steals some from neighboring nests.
The clutch consists of three to four whitish eggs. It is incubated by the female alone for eleven days. However, the male parent bird is involved in feeding the nestlings. The nestling period is 15 days.
Systematics
The chestnut sparrow, the Yemen gold sparrow and the brown-backed gold sparrow were long considered the most original species within the genus Passer with only a relatively low degree of relationship to the house sparrow and the other black-throated sparrow species found in the Palearctic . They were therefore occasionally placed in the genus Auripasser . However, studies of mitochondrial DNA indicate that both the chestnut sparrow and the Yemen and brown-backed golden sparrow either descend from or are closely related to these black-throated sparrow species.
literature
- Horst Bielfeld : Knowing and caring for 300 ornamental birds. Ulmer Verlag, Stuttgart 2009, ISBN 978-3-8001-5737-2 .
- C. Hilary Fry and Stuart Keith (Eds.): The Birds of Africa. Volume VII. Christopher Helm, London 2004, ISBN 0-7136-6531-9 .
Web links
- Passer luteus inthe IUCN Red List of Threatened Species 2010.4. Listed by: BirdLife International, 2009. Retrieved December 6, 2010.
Single receipts
- ↑ a b c Fry et al., P. 37
- ↑ Fry et al., P. 36
- ↑ Fry et al., Pp. 36-37
- ↑ Fry et al., Pp. 37-38
- ↑ a b c d Fry et al., P. 38
- ↑ Fry et al., P. 8
- ↑ Fry et al., P. 39
- ↑ Luis M. Allende, Rubio, Isabel; Ruíz-del-Valle, Valentin; Guillén, Jesus; Martínez-Laso, Jorge; Lowy, Ernesto; Varela, Pilar; Zamora, Jorge; Arnaiz-Villena, Antonio: The Old World sparrows (genus Passer ) phylogeography and their relative abundance of nuclear mtDNA pseudogenes . (PDF) In: Journal of Molecular Evolution . 53, No. 2, 2001, pp. 144-154. PMID 11479685 .