Grey-capped social weaver

Last updated

Grey-capped social weaver
Pseudonigrita-arnaudi-Amboseli.JPG
In Amboseli, Kenya
Scientific classification Red Pencil Icon.png
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Passeriformes
Family: Ploceidae
Genus: Pseudonigrita
Species:
P. arnaudi
Binomial name
Pseudonigrita arnaudi
(Bonaparte, 1850) [2]
Nigrita arnaudi map.svg
Synonyms
  • Nigrita arnaudi

The grey-capped social weaver (Pseudonigrita arnaudi) is a sparrow-like liver-colored bird, with a pale grey crown, a dark grey bill, a whitish eye-ring, horn-colored legs, with some black in the wing and a light terminal band in the tail, that builds roofed nests made of straws, breeds in colonies in thorny Acacia trees, and feeds in groups gathering grass seeds and insects. Male and female have near identical plumage. DNA-analysis confirms it is part of the weaver family. It is found in Ethiopia, Kenya, Somalia, South Sudan, Sudan, Tanzania, and Uganda.

Contents

Taxonomy

The French naturalist Charles Lucien Bonaparte described the grey-capped social weaver as Nigrita arnaudi in 1850. [2] He chose the specific epithet to honor Joseph Pons d'Arnaud, the French explorer who had collected a specimen around 1841 near Juba on the White Nile, and sent it to the French Museum of Natural History. In 1903, the German zoologist Anton Reichenow assigned the species to his newly erected genus Pseudonigrita , because he considered P. arnaudi and P. cabanisi related to weaverbirds (Ploceidae), while the other species Nigrita bicolor , N. canicapillus , N. fusconota and N. luteifrons are negrofinches assigned to the estrildid finches. [3] [4]

Ludwig Reichenbach called it Arnauds nigrita in 1863. [4] The "grey-capped social weaver" is the name used by the International Ornithological Committee (IOC). [5] Other common names include grey-headed social weaver and Masai grey-headed social weaver. [4]

Phylogeny

Based on a molecular phylogenetic study published in 2017 (which did not include P. cabanisi ), the genus Pseudonigrita belongs to the group of sparrow weavers (subfamily Plocepasserinae), and is most closely related to Philetairus socius . This clade is sister to Plocepasser . [6] Provided that the sister relationship between the Pseudonigrita-species is correct, the following tree expresses current insights.

Ploceidae
Amblyospizinae

Amblyospiza albifrons

Plocepasserinae

Sporopipes

Plocepasser

Philetairus socius

Pseudonigrita cabanisi

Pseudonigrita arnaudi

Bubalornithinae

Dinemellia dinemelli

Bubalornis

Ploceinae

all other weaverbirds

Subspecies and distribution

Three subspecies of the grey-capped social weaver are recognised. [5] The southerly subspecies dorsalis can be distinguished by its bluish grey instead of livery brown back.

Description

The grey-capped social weaver is small for a weaver with 11–12 cm (4.3–4.7 in) long, and it weighs 15–26 g (0.53–0.92 oz). It is a sparrow-like liver-colored bird, with a pale grey crown, a dark grey bill, a whitish eye-ring, horn-colored legs, with some black in the wing and a light terminal band in the for a weaver relatively short tail. [8] The tail band is visible during flight. [9] The cap of the adult male is almost white, that of females more light grey. Adolescents have a duller plumage, a brown bill, and the cap is light liver-colored. [8] [7]

The birds make long series of seven to ten high-pitched piercing squeaks, sounding like tseeer-tseeer-tseeer-.... [7] [10]

Behaviour

Arriving with building material Pseudonigrita arnaudi Amboseli gate 1.jpg
Arriving with building material
Nest with two entrances below Pseudonigrita arnaudi Amboseli gate 2.jpg
Nest with two entrances below

The grey-capped social weaver is monogamous and breeds in colonies. [4] Its behavior closely resembles that of the sociable weaver Philetairus socius. [11] [12]

In studies conducted in Kenya, some individuals were observed to rest in their nests year round, even outside the breeding periods, with two to five together. The immediate surroundings of the nests were generally not defended against birds from other families that nested or slept in the same Acacia tree housing the colony. However, birds from other trees were usually attacked when landing in the colony tree. The order in which birds are allowed to feed was according to dominance, although members from other families from the same colony where better tolerated than birds from other colonies. Aggression was rare or absent between members of the same group. [11] [12]

Feeding

The grey-capped social weaver feeds on both grass seeds and insects, such as grasshoppers, beetles, termites and caterpillars. Feeding mostly takes place in groups at some distance from the colony. [7]

Breeding

Grey-capped social weavers breed colonially. The nests are not only used for breeding but also for fully grown birds to sleep in at night. Breeding takes place throughout the year, but there is a peak that enables the birds to make use of periods that food is plenty, such as between August and December in South Sudan and between March and May in eastern Africa. Nests are built hanging from thin branches, often in Vachellia drepanolobium , and sometimes in other acacia species such as the umbrella thorn acacia ( V. tortilis ), blackthorn ( Senegalia mellifera ) or gum acacia ( S. senegal ). The roofed nests have thick walls and are constructed from grass straws, which, in the dry climate keep well for many months. Nest are often constructed with two or three side-to-side or under old nests. One of the two entrances is closed just before the eggs are laid and opened again around the moment of fledging. [4] [11] [12] The clutch consists of four eggs. They are approximately 19 mm (0.75 in) in length and 14 mm (0.55 in) in diameter, greenish, bluish or white, unadorned or with fine black or olive colored specks, more dense at thick end, or so heavily blotched that the overall color seems olive-brown or ash-grey. Both parents incubate the eggs but the female spends about twice as much time incubating as the male. The eggs hatch after thirteen or fourteen days. [4] The nestlings are initially fed on a diet consisting exclusively of insects, and grass seeds are only given during the last days. Fledging occurs after about twenty days. [8] [11] [12] Adult and adolescent birds from previous broods often help in nest building and feeding the chicks. [8] [11] [12]

Roofed nests, with two downward-facing nest entrances, colony nesting, and choosing a thorny nesting tree, are all considered adaptations that help limit predation. Aggregated nests, thick walls and communal sleeping are considered adaptations against the cold nights in the arid distribution area of P. arnaudi. [12]

Chestnut sparrows (Passer eminibey) sometimes drive grey-capped social weavers from their nests to take them over. Cut-throat finches (Amadina fasciata) however only use deserted nests. [4]

Aviculture

The grey-capped social weaver is sometimes kept and bred in captivity by hobbyists. Due to its social structure, P. arnaudi only starts breeding when in larger established groups (at least about ten pairs). It needs large and high cages, and thin branches to attach the nest and much suitable nesting material (grass straws) needs to be available. A specialised website suggest a ground cover of sand beneath the nesting branches, and grass elsewhere, inter-planted with a few very resistant shrubs. Adults fare well on a diet of 95% seeds and 5% insects, but during the breeding season about 20% of the food should consist of living insects, such as mealworms and small crickets. Fine stone grit and calcium sources, such as shell grit and cuttlebone, need to be provided. Due to its large demand in nesting material, excessive theft may occur if other Plocepasserinae-species are kept in the same confinement. This website also suggests to compose a group at one instance and not to introduce other birds later, particularly during breeding. [8]

Related Research Articles

<span class="mw-page-title-main">Ploceidae</span> Family of small passerine birds

Ploceidae is a family of small passerine birds, many of which are called weavers, weaverbirds, weaver finches and bishops. These names come from the nests of intricately woven vegetation created by birds in this family. In most recent classifications, Ploceidae is a clade, which excludes some birds that have historically been placed in the family, such as some of the sparrows, but which includes the monotypic subfamily Amblyospizinae. The family is believed to have originated in the mid-Miocene. All birds of the Ploceidae are native to the Old World, most in Africa south of the Sahara, though a few live in tropical areas of Asia. A few species have been introduced outside their native range.

<span class="mw-page-title-main">Clay-colored sparrow</span> Species of bird

The clay-colored sparrow or clay-coloured sparrow is a small New World sparrow of North America.

<span class="mw-page-title-main">Village weaver</span> Species of bird in the Ploceidae family

The village weaver , also known as the spotted-backed weaver or black-headed weaver, is a species of bird in the family Ploceidae found in much of sub-Saharan Africa. It has also been introduced to Portugal and Venezuela as well as to the islands of Hispaniola, Martinique, Puerto Rico, Mauritius and Réunion.

<span class="mw-page-title-main">Black-necked weaver</span> Species of bird

The black-necked weaver is a resident breeding bird species in much of tropical Africa from Senegal and northern Angola to South Sudan and Tanzania.

<span class="mw-page-title-main">Red-billed quelea</span> A small, migratory weaver bird native to Sub-Saharan Africa

The red-billed quelea, also known as the red-billed weaver or red-billed dioch, is a small—approximately 12 cm (4.7 in) long and weighing 15–26 g (0.53–0.92 oz)—migratory, sparrow-like bird of the weaver family, Ploceidae, native to Sub-Saharan Africa.

<span class="mw-page-title-main">Chestnut sparrow</span> Species of bird

The chestnut sparrow is a species of passerine bird in the sparrow family Passeridae. It is the smallest member of the sparrow family, at about 11 cm (4.3 in) long. The breeding male has deep chestnut plumage and the female and juvenile are coloured a duller grey with some chestnut markings. Like its closest relatives in the genus Passer, the Arabian golden sparrow and the Sudan golden sparrow, it is gregarious and found in arid areas. Ranging through the east of Africa from Darfur in Sudan to Tanzania, it is found in dry savanna, papyrus swamps, and near human habitation. Adults and juveniles both feed mostly on grass seeds, and fly in flocks, often with other species of birds, to find food. It nests in trees, building its own domed nests, and also usurping the more elaborate nests of weavers.

<span class="mw-page-title-main">Swainson's sparrow</span> Species of bird

Swainson's sparrow is a species of bird in the sparrow family Passeridae. Sometimes considered a subspecies of the grey-headed sparrow, it occurs in northeastern Africa, largely in the Ethiopian Highlands. This sparrow was named after the English naturalist and illustrator William John Swainson.

<span class="mw-page-title-main">Cape sparrow</span> A small passerine bird from southern Africa

The Cape sparrow, or mossie, is a bird of the sparrow family Passeridae found in southern Africa. A medium-sized sparrow at 14–16 centimetres (5.5–6.3 in), it has distinctive plumage, including large pale head stripes in both sexes. Its plumage is mostly grey, brown, and chestnut, and the male has some bold black and white markings on its head and neck. The species inhabits semi-arid savannah, cultivated areas, and towns, and ranges from the central coast of Angola to eastern South Africa and Eswatini. Three subspecies are distinguished in different parts of its range.

<span class="mw-page-title-main">Baya weaver</span> Species of bird found in southeast Asia

The baya weaver is a weaverbird found across the Indian Subcontinent and Southeast Asia. Flocks of these birds are found in grasslands, cultivated areas, scrub and secondary growth and they are best known for their hanging retort shaped nests woven from leaves. These nest colonies are usually found on thorny trees or palm fronds and the nests are often built near water or hanging over water where predators cannot reach easily. They are widespread and common within their range but are prone to local, seasonal movements mainly in response to rain and food availability.

<span class="mw-page-title-main">White-headed buffalo weaver</span> Species of bird

The white-headed buffalo weaver or white-faced buffalo-weaver is a species of passerine bird in the family Ploceidae native to East Africa. The buffalo part of its name derives from its habit of following the African buffalo, feeding on disturbed insects. Two subspecies are recognized.

Social weaver can refer to any of three African birds:

<span class="mw-page-title-main">Bird colony</span> Large congregation of birds at a particular location

A bird colony is a large congregation of individuals of one or more species of bird that nest or roost in proximity at a particular location. Many kinds of birds are known to congregate in groups of varying size; a congregation of nesting birds is called a breeding colony. Colonial nesting birds include seabirds such as auks and albatrosses; wetland species such as herons; and a few passerines such as weaverbirds, certain blackbirds, and some swallows. A group of birds congregating for rest is called a communal roost. Evidence of colonial nesting has been found in non-neornithine birds (Enantiornithes), in sediments from the Late Cretaceous (Maastrichtian) of Romania.

<span class="mw-page-title-main">Taita fiscal</span> Species of bird

The Taita fiscal or Teita fiscal is a member of the shrike family found in east Africa from southeastern South Sudan, southern Ethiopia, and western Somalia to northeastern Tanzania. Its habitat is dry open thornbush and acacia and other dry open woodland.

<span class="mw-page-title-main">Red-billed buffalo weaver</span> Species of bird

The red-billed buffalo weaver is a species of bird in the family Ploceidae. It is found in eastern and southern Africa. Its natural habitat is the dry savanna.

<span class="mw-page-title-main">Sociable weaver</span> Species of bird

The sociable weaver is a species of bird in the weaver family that is endemic to southern Africa. It is the only species in the monotypic genus Philetairus. It is found in South Africa, Namibia, and Botswana. but their range is centered within the Northern Cape Province of South Africa. They build large compound community nests, a rarity among birds. These nests are perhaps the most spectacular structure built by any bird.

<span class="mw-page-title-main">Sparrow-weaver</span> Genus of birds

The sparrow-weavers (Plocepasser) are a genus of birds in the family Ploceidae (weavers), but some taxonomic authorities place them in the family Passeridae.

<span class="mw-page-title-main">Orange weaver</span> Species of bird

The orange weaver is a species of bird in the weaver family, Ploceidae. It is sparsely distributed across African tropical rainforest.

<span class="mw-page-title-main">Nelicourvi weaver</span> Species of bird

The nelicourvi weaver is a species of bird in the family Ploceidae. It is endemic to Madagascar. Together with its closest relative, the sakalava weaver, it is sometimes placed in a separate genus Nelicurvius. A slender, sparrow-like bird, it is 15 cm (5.9 in) long and weighing 20–28 g (0.71–0.99 oz). Breeding males have a black bill and head, brown eyes, yellow collar, grey belly, chestnut-brown lower tail coverts, olive back, and blackish flight feathers edged greenish. Non-breeding males have mottled grey and green heads. In the breeding female the front of the head is yellow and the back olive green, with a broad yellow eyebrow. It builds solitary, roofed, retort-shaped nests, hanging by a rope from a branch, vine or bamboo stem, in an open space. It primarily feeds on insects, looking on its own or in very small groups, often together with long-billed bernieria. Its natural habitat is subtropical or tropical moist lowland and mountain forests. The conservation status of Nelicourvi weaver is least concern according to the IUCN Red List.

<i>Pseudonigrita</i> Genus of birds

Pseudonigrita is a genus of sparrow-like birds in the weaverbird family.

<span class="mw-page-title-main">Black-capped social weaver</span> Species of bird

The black-capped social weaver is a sparrow-like species of bird that has been assigned to the weaverbird family. It was originally described by Fisher and Reichenow, and later re-classified by the latter to the genus Pseudonigrita. Adults have a large black cap, ivory-colored bill, red eyes, brown back and wings, blackish-brown tail, white throat and underparts with a black midline, and dark horn-colored legs. It breeds in colonies and roofed nests with an entrance at the bottom in thorny trees such as acacias are constructed by the male from grass stems. It is found in parts of Ethiopia, Kenya, Somalia, and Tanzania. It is sometimes kept and bred in captivity.

References

  1. BirdLife International (2016). "Pseudonigrita arnaudi". IUCN Red List of Threatened Species . 2016: e.T22718718A94593477. doi: 10.2305/IUCN.UK.2016-3.RLTS.T22718718A94593477.en . Retrieved 12 November 2021.
  2. 1 2 Bonaparte, Charles Lucien (1850). Conspectus generum avium (in Latin). Lugduni Batavorum [Leiden, Netherlands]: E.J. Brill. p. 444.
  3. Boetticher, Hans von (1942). "Der kleine Schwarzkopf-Sperlingsweber" (PDF). Verhandlungen der Ornithologischen Gesellschaft in Bayern (in German). 22 (2): 207–210. Retrieved 2017-04-23.
  4. 1 2 3 4 5 6 7 8 "Grey-headed Social Weaver Pseudonigrita arnaudi". Weaver Watch - Monitoring the Weavers of the World. Retrieved 2017-04-03.
  5. 1 2 Gill, Frank; Donsker, David; Rasmussen, Pamela, eds. (January 2021). "Old World sparrows, snowfinches, weavers". IOC World Bird List Version 11.1. International Ornithologists' Union. Retrieved 20 February 2021.
  6. De Silva, Thilina N.; Peterson, A. Townsend; Bates, John M.; Fernandoa, Sumudu W.; Girard, Matthew G. (2017). "Phylogenetic relationships of weaverbirds (Aves: Ploceidae): A first robust phylogeny based on mitochondrial and nuclear markers". Molecular Phylogenetics and Evolution. 109: 21–32. doi:10.1016/j.ympev.2016.12.013. PMID   28012957.
  7. 1 2 3 4 Craig, A. (2017). "Grey-capped Social-weaver (Pseudonigrita arnaudi)". In del Hoyo, J.; Elliott, A.; Sargatal, J.; Christie, D.A.; de Juana, E. (eds.). Handbook of the Birds of the World Alive. Barcelona: Lynx Edicions. cited on "Grey-capped Social-weaver" . Retrieved 2017-04-01.
  8. 1 2 3 4 5 "Marmerwever Pseudonigrita arnaudi". Werkgroep voor Ploceidae (in Dutch). Retrieved 2017-04-10.
  9. Redman, Nigel; Stevenson, Terry; Fanshawe, John (2009). Birds of the Horn of Africa Ethiopia, Eritrea, Djibouti, Somalia, Socotra. London: Christopher Helm. p. 304. ISBN   9781408135761.
  10. Redman, Nigel; Stevenson, Terry; Fanshawe, John (2010). Birds of the Horn of Africa: Ethiopia, Eritrea, Djibouti, Somalia and Socotra. Bloomsbury Publishing. ISBN   9781408135761 . Retrieved 2017-04-17.
  11. 1 2 3 4 5 Collias, Nicholas E.; Collias, Elsie C. (1977). "Weaverbird nest aggregation and evolution of the compound nest". The Auk. 94 (1): 50–64. JSTOR   4084889.
  12. 1 2 3 4 5 6 Collias, Nicholas E.; Collias, Elsie C. (1980). "Behavior of the Grey-Capped Social Weaver (Pseudonigrita arnaudi) in Kenya". The Auk. 97 (2): 213–226. JSTOR   4085697.