Red-billed quelea
The red-billed quelea, also known as the red-billed weaver or red-billed dioch, is a small, seasonally nomadic, sparrow-like bird of the weaver family, Ploceidae, native to sub-Saharan Africa. It is approximately long and weighs.
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 Q. q. 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 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 red-billed 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". The usual pest-control measures are spraying avicides or detonating fire-bombs in the enormous colonies during the night. Extensive control measures have been largely unsuccessful in limiting the quelea population. When food runs out, the species moves to locations of recent rainfall and plentiful grass seed; hence it exploits its food source very efficiently. It 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. It feeds in huge flocks of millions of individuals, with birds that run out of food at the rear flying over the entire group to a fresh feeding zone at the front, creating an image of a rolling cloud. The conservation status of red-billed quelea is least concern according to the IUCN Red List.
Taxonomy and naming
The red-billed quelea was one of the many birds described originally by Linnaeus in the landmark 1758 10th edition of his Systema Naturae. Classifying it in the bunting genus Emberiza, he gave it the binomial name of Emberiza quelea. 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. In 1850, Ludwig Reichenbach thought the species was not a true bunting, but rather a weaver, and created the genus name Quelea, as well as the new combination Q. quelea. The white-faced morph was described as a separate species, Q. russii by Otto Finsch in 1877 and named after the aviculturist Karl Russ.
Three subspecies are recognised. In the field, these are distinguished by differences in male breeding plumage.
- The nominate subspecies, Quelea quelea quelea, is native to west and central Africa, where it has been recorded from Mauritania, western and northern Senegal, Gambia, central Mali, Burkina Faso, southwestern and southern Niger, northern Nigeria, Cameroon, south-central Chad and northern Central African Republic.
- Loxia lathamii was described by Andrew Smith in 1836, 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, southern Democratic Republic of Congo and the mouth of the Congo River, Zambia, Malawi and western Mozambique across to Namibia 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.
Etymology and vernacular names
Linnaeus himself did not explain the name quelea. Quelea quelea is locally called kwelea domo-jekundu in Swahili, enzunge in Kwangali, chimokoto in Shona, inyonyane in Siswati, thaha in Sesotho and ndzheyana in the Tsonga language. 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. 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.
Phylogeny
Based on recent DNA analysis, the red-billed quelea is the sister group of a clade that contains both other remaining species of the genus Quelea, namely the cardinal quelea and the red-headed quelea. The genus belongs to the group of true weavers, and is most closely related to the fodies, a genus of six or seven species that occur on the islands of the western Indian Ocean. These two genera are in turn the sister clade to the Asian species of the genus Ploceus. The following tree represents current insight of the relationships between the species of Quelea, and their closest relatives.Interbreeding between red-billed and red-headed queleas has been observed in captivity.
Description
The red-billed quelea is a small sparrow-like bird, approximately long and weighing, with a heavy, cone-shaped bill, which is red or orange to yellow.Over 75% of males have a black facial "mask", comprising a black forehead, cheeks, lores and higher parts of the throat. Occasionally males have a white mask. 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.
The females resemble the males in non-breeding plumage, but have a yellow or orangey bill and eye-ring during the breeding season. At other times, the female bill is pink or dull red.
Newborns have white bills and are almost naked with some wisps of down on the top of the head and the shoulders. The eyes open during the fourth day, at the same time as the first feathers appear. Older nestlings have a horn-coloured bill with a hint of lavender, though it turns orange-purple before the post-juvenile moult. Young birds change feathers two to three months after hatching, after which the plumage resembles that of non-breeding adults, although the head is grey, the cheeks whitish, and wing coverts and flight feathers have buff margins. At an age of about five months they moult again and their plumage starts to look like that of breeding adults, with a pinkish-purple bill.
Different subspecies are distinguished by different colour patterns of the male breeding plumage. In the typical subspecies, Q. quelea quelea, breeding males have a buff crown, nape and underparts and the black mask extends high up the forehead. In Q. quelea lathamii the mask also extends high up the forehead, but the underparts are mainly white. In Q. quelea aethiopica the mask does not extend far above the bill, and the underparts may have a pink wash. There is much variability within subspecies, and some birds cannot be ascribed to a subspecies based on outward appearance alone. Because of interbreeding, specimens intermediate between subspecies may occur where the ranges of the subspecies overlap, such as at Lake Chad.
The female pin-tailed whydah could be mistaken for the red-billed quelea in non-breeding plumage, since both are sparrow-like birds with conical red-coloured bills, but the whydah has a whitish brow between a black stripe through the eye and a black stripe above.