Красноклювый ткачик: Описание и распространение

Small, migratory weaver bird native to Sub Saharan Africa

The red billed quelea ('/k//w//iː//l//i//ə/; Quelea quelea), also known as the red billed weaver or red billed dioch, is a small—approximately long and weighing —migratory, sparrow like bird of the weaver family, Ploceidae, native to Sub Saharan Africa. It was named by Linnaeus in 1758, who considered it a bunting, but Ludwig Reichenbach assigned it in 1850 to the new genus Quelea. Three subspecies are recognised, with Quelea quelea quelea occurring roughly from Senegal to Chad, Q. q. aethiopica from Sudan to Somalia and Tanzania, and Q. q. lathamii from Gabon to Mozambique and South Africa. Non breeding birds have light underparts, striped brown upper parts, yellow edged flight feathers and a reddish bill. Breeding females attain a yellowish bill. Breeding males have a black (or rarely white) facial mask, surrounded by a purplish, pinkish, rusty or yellowish wash on the head and breast. The species avoids forests, deserts and colder areas such as those at high altitude and in southern South Africa. It constructs oval roofed nests woven from strips of grass hanging from thorny branches, sugar cane or reeds. It breeds in very large colonies. The quelea feeds primarily on seeds of annual grasses, but also causes extensive damage to cereal crops. Therefore, it is sometimes called "Africa's feathered locust". He incorrectly mentioned that it originated in India, probably because ships from the East Indies picked up birds when visiting the African coast during their return voyage to Europe. It is likely that he had seen a draft of Ornithologia, sive Synopsis methodica sistens avium divisionem in ordines, sectiones, genera, species, ipsarumque varietates, a book written by Mathurin Jacques Brisson that was to be published in 1760, and which contained a black and white drawing of the species. The erroneous type locality of India was corrected to Africa in the 12th edition of Systema Naturae of 1766, and Brisson was cited. Brisson mentions that the bird originates from Senegal, where it had been collected by Michel Adanson during his 1748 1752 expedition. He called the bird Moineau à bec rouge du Senegal in French and Passer senegalensis erythrorynchos in Latin, both meaning "red billed Senegalese sparrow". Also in 1766, George Edwards illustrated the species in colour, based on a live male specimen owned by a Mrs Clayton in Surrey. He called it the "Brazilian sparrow", despite being unsure whether it came from Brazil or Angola. The white faced morph was described as a separate species, Q. russii by Otto Finsch in 1877 and named after the aviculturist Karl Russ. but later assigned to Q. quelea as its subspecies lathamii. It ranges across central and southern Africa, where it has been recorded from southwestern Gabon, southern Congo, Angola (except the northeast and arid coastal southwest), southern Democratic Republic of Congo and the mouth of the Congo River, Zambia, Malawi and western Mozambique across to Namibia (except the coastal desert) and central, southern and eastern South Africa. Ploceus aethiopicus was described by Carl Jakob Sundevall in 1850, but later assigned to Q. quelea as its subspecies aethiopica. It is found in eastern Africa where it occurs in southern Sudan, eastern South Sudan, Ethiopia and Eritrea south to the northeastern parts of the Democratic Republic of Congo, Uganda, Kenya, central and eastern Tanzania and northwestern and southern Somalia. Hence it is not recognised as distinct. Q. quelea intermedia, described by Anton Reichenow in 1886 from east Africa, is regarded a synonym of subspecies aethiopica.

Linnaeus himself did not explain the name quelea. M. W. Jeffreys suggested that the term came from medieval Latin qualea, meaning "quail", linking the prodigious numbers of queleas to the hordes of quail that fed the Israelites during the Exodus from Egypt. The subspecies lathamii is probably named in honor of the ornithologist John Latham. The name of the subspecies aethiopica refers to Ethiopia, and its type was collected in the neighbouring Sennar province in today's Sudan. "Red billed quelea" has been designated the official name by the International Ornithological Committee (IOC). Other names in English include black faced dioch, cardinal, common dioch, Latham's weaver bird, pink billed weaver, quelea finch, quelea weaver, red billed dioch, red billed weaver, Russ' weaver, South African dioch, Sudan dioch and Uganda dioch. Interbreeding between red billed and red headed queleas has been observed in captivity. The mask is surrounded by a variable band of yellow, rusty, pink or purple. White masks are sometimes bordered by black. This colouring may only reach the lower throat or extend along the belly, with the rest of the underparts light brown or whitish with some dark stripes. The upperparts have light and dark brown longitudinal stripes, particularly at midlength, and are paler on the rump. The tail and upper wing are dark brown. The flight feathers are edged greenish or yellow. The eye has a narrow naked red ring and a brown iris. The legs are orangey in colour. The bill is bright raspberry red. Outside the breeding season, the male lacks bright colours; it has a grey brown head with dark streaks, whitish chin and throat, and a faint light stripe above the eyes. At this time, the bill becomes pink or dull red and the legs turn flesh coloured.

Flying flocks make a distinct sound due to the many wing beats. After arriving at the roost or nest site, birds keep moving around and make a lot of noise for about half an hour before settling in. The male sings in short bursts, starting with some chatter, followed by a warbling tweedle toodle tweedle.

The red billed quelea is regarded as the most numerous undomesticated bird on earth, with the total post breeding population sometimes peaking at an estimated 1.5 billion individuals. Small groups of red billed queleas often mix with different weaver birds (Ploceus) and bishops (Euplectes), and in western Africa they may join the Sudan golden sparrow (Passer luteus) and various estrildids. Red billed queleas may also roost together with weavers, estrildids and barn swallows. Nests are usually built in stands of thorny trees such as umbrella thorn acacia (Vachellia tortilis), blackthorn (Senegalia mellifera) and sicklebush (Dichrostachys cinerea), but sometimes in sugar cane fields or reeds. Colonies can consist of millions of nests, in densities of 30,000 per ha (12,000 per acre). Over 6000 nests in a single tree have been counted. At Malilangwe in Zimbabwe one colony was long and wide. The male starts the nest by creating a ring of grass by twining strips around both branches of a hanging forked twig, and from there bridging the gaps in the circle his beak can reach, having one foot on each of the branchlets, using the same footholds and the same orientation throughout the building process. Two parallel stems of reeds or sugar cane can also be used to attach the nest from. They use both their bills and feet in adding the initial knots needed. As soon as the ring is finished the male displays, trying to attract a female, after which the nest may be completed in two days. The nest chamber is created in front of the ring. The entrance may be constructed after the egg laying has started, while the male works from the outside. A finished nest looks like a small oval or globular ball of grass, around 18 cm (7 in) high and 16 cm (6 in) wide, with a 2.5 cm (1 in) wide entrance high up one side, sheltered by a shallow awning. About six to seven hundred fresh, green grass strips are used for each nest. When the supply of these seeds runs out, seeds of cereals such as barley (Hordeum disticum), teff (Eragrostis tef), sorghum (Sorghum bicolor), manna (Setaria italica), millet (Panicum miliaceum), rice (Oryza sativa), wheat (Triticum), oats (Avena aestiva), as well as buckwheat (Phagopyrum esculentum) and sunflower (Helianthus annuus) are eaten on a large scale. Red billed queleas have also been observed feeding on crushed corn from cattle feedlots, but entire maize kernels are too big for them to swallow. A single bird may eat about in seeds each day. Breeding females consume snail shell fragments and calcareous grit, presumably to enable egg shell formation. Among the invertebrates that kill and eat youngsters are the armoured bush cricket (Acanthoplus discoidalis) and the scorpion Cheloctonus jonesii. Internal parasites found in queleas include Haemoproteus and Plasmodium. Woven traps made from star grass (Cynodon nlemfuensis) are used to catch hundreds of these birds daily in the Kondoa District, Tanzania.

Sometimes called "Africa's feathered locust", Attempts during the 1950s and '60s to eradicate populations, at least regionally, failed. Consequently, management is at present directed at removing those congregations that are likely to attack vulnerable fields. In eastern and southern Africa, the control of quelea is often coordinated by the Desert Locust Control Organization for Eastern Africa (DLCO EA) and the International Red Locust Control Organization for Central and Southern Africa (IRLCO CSA), which make their aircraft available for this purpose.