Thick-billed weaver

Thick-billed weaver
Nominate male in Pretoria, South Africa
Scientific classification
Kingdom:Animalia
Phylum:Chordata
Class:Aves
Order:Passeriformes
Family:Ploceidae
Genus:Ambylospiza
Species: A. albifrons
Binomial name
Amblyospiza albifrons
(Vigors, 1831)
Synonyms
  • Pyrrhula albifrons Vigors, 1831

The thick-billed weaver or grosbeak weaver (Amblyospiza albifrons) is a distinctive and bold species of weaver bird that is native to the Afrotropics. It comprises the monotypic genus Amblyospiza[2] and subfamily Amblyospizinae.[3]

They have particularly strong mandibles, which are employed to extricate the seeds in nutlets and drupes, and their songs are comparatively unmusical and harsh. Their colonial nests are readily distinguishable from those of other weavers, due to their form and placement, and the fine strands used in their construction.

They habitually fan and flick their tails.

Range

It has a patchy distribution in West, East and southern Africa,[4] where it is present in marshes, uplands, suburban areas and artificial wetlands.

It is found in Angola, Benin, Botswana, Burundi, Cameroon, CAR, Republic of the Congo, DRC, Ivory Coast, Equatorial Guinea, Ethiopia, Gabon, Ghana, Guinea, Kenya, Liberia, Malawi, Mozambique, Namibia, Nigeria, Rwanda, Senegal, Sierra Leone, Somalia, South Africa, South Sudan, Swaziland, Tanzania, Togo, Uganda, Zambia, and Zimbabwe.[1]

Habitat

Thick-billed weavers breed in reedy wetlands and can be found around forest edge outside the breeding season.[5]

Nesting

The thick-billed weaver constructs a distinctive nest which is compact, woven with thin strips of reeds and hung between the upright stems of reeds. It is globe-shaped with the entrance (unlike other weaver nests) near the top and facing to the side. The male weaves the nest with fine material leaving a neat impression, but the weave is in fact not as complex or developed as that of other weaver species. The initial entrance is large, but when a female has chosen the nest the entrance reduced to a narrow opening. Thick-billed weaver colonies may involve a single male, or may contain several males, and is usually established in a reed swamp.[5]

Thick-billed weavers are polygynous, in that a single male attempts to attract and mate with several females. A male may attract up to six females, and up to three nests may be active in any male's territory at once. When found at low density there are many apparently monogamous pairs, but they normally nest in small colonies. More than 100 nests have been counted in one South African colony. After mating the female normally will lay a clutch of 3 whitish pink eggs, spotted with red, purple and brown. The incubation of the eggs is carried out solely by the female. This lasts 14 to 16 days and the chicks are fed by regurgitation by the female until they fledge, though occasionally the male may also feed the young. The chicks fledge after about 18 to 20 days in the nest. The nests are vulnerable to predation and recorded nest predators include the white-browed coucal, house crow and the Nile monitor. After the nests have been used by the weavers they may be commandeered by climbing mice, or used for breeding by the orange-breasted waxbill or brown firefinch.[5]

Subspecies

There are five accepted subspecies:[6]

  • A. a. capitalba (Bonaparte, 1850) – discontinuously from south eastern Guinea to southern CAR and north western Angola
  • A. a. melanota (Heuglin, 1863) – South Sudan and southern Ethiopia, through the rift valley and adjacent lowlands to north western Tanzania
  • A. a. montana van Someren, 1921 – Kenyan and Tanzanian interior, south eastern DRC to Malawi and Okavango Basin
  • A. a. unicolor (G.A.Fischer & Reichenow, 1878) – East coast littoral from southern Somalia to Zanzibar and Pemba islands.
  • A. a. albifrons (Vigors, 1831) – eastern Zimbabwe and central Mozambique, southwards to eastern South Africa

Naming

The generic name Amblyospiza was coined by Carl Jakob Sundevall in 1850 and means "blunt, finch", referencing the very large bill, while the specific name albifrons refers white forehead of the males. The thick-billed weaver was formally described as Pyrrhula albifrons in 1831 by the Irish zoologist and politician Nicholas Aylward Vigors from the collection of Henry Ellis, the specimens of which were attributed to Algoa Bay and environs in the Eastern Cape.[5]

References

  1. 1 2 BirdLife International (2012). "Amblyospiza albifrons". IUCN Red List of Threatened Species. Version 2013.2. International Union for Conservation of Nature. Retrieved 26 November 2013.
  2. ↑ "ITIS Report: Amblyospiza". Integrated Taxonomic Information System. Retrieved 14 March 2013.
  3. ↑ De Silva, Thilina N.; Peterson, A. Townsend; Bates, John M.; Fernando, Sumudu W.; Girard, Matthew G. (April 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. Retrieved 1 September 2017.
  4. ↑ "Amblyospiza albifrons (Thick-billed weaver)". Biodiversity Explorer. Iziko Museums. Retrieved 30 March 2016.
  5. 1 2 3 4 "Thick-billed Weaver Amblyospiza albifrons". Weaver Watch. ADU - UCT. Retrieved 19 October 2016.
  6. ↑ "Thick-billed Weaver (Amblyospiza albifrons) - HBW 15, p. 138". Weavers (Ploceidae). The Internet Bird Collection. Retrieved 1 April 2016.
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.