The above is based on Weaver Wednesday 2, a weekly series about the discovery of each weaver species.
This species text first appeared as Weaver Wednesday [227] – Discovery [110]: Usambara Weaver on 2016-10-19
1. Basic biology
Usambara Weaver, figure from Nik BorrowUsambara Weaver, figure – stamp from Palestine
Identification. The Usambara Weaver is a rare weaver restricted to Tanzanian mountain forests. It is black above with a yellow belly and flanks. It is distinguished from the Dark-backed Weaver, with which it associates, by the yellow eye and large chestnut patch on the breast. It was previously treated as a race of the similar Olive-headed Weaver but the Usambara Weaver has a darker back and different habitat.
Distribution. The Usambara Weaver occurs at low densities in montane forests in the Eastern Arc Mountains of Tanzania, where it appears to have a very small and greatly fragmented population (see map above, based on Birds of Africa).
Map colours:
Light green – West Usambaras – frequent
Blue – Mt Nilo in the East Usambaras – present
Grey – Ulugurus – rare
Red – Udzungwa Mountains – sparse but widespread.
Usambara Weaver nest, figure from PHOWN
No races are recognised, although birds in the south have sometimes been recognized as a separate race based on minor plumage differences. It is considered rare, since forest is highly fragmented and is being progressively cleared for agriculture, timber and plantations. Its global population is currently estimated to be less than 2500 individuals, and declining.
Habitat. The Usambara Weaver inhabits the canopy of montane evergreen forests. It occasionally occurs at forest edge, in disturbed forest, plantations and in isolated trees in cultivated areas. The Usambara Weaver occurs singly, in pairs, or in mixed-species flocks, often with the Dark-backed Weaver.
Food. The Usambara Weaver feeds on insects. It often hangs upside-down from branches while foraging, to glean insects from trees covered in epiphytes. It also probes bark and lichen for hidden food.
Breeding. The Usambara Weaver is probably monogamous. The nest resembles that of the Dark-backed Weaver, being constructed from dry tendrils and creepers, but it has a shorter entrance tunnel with a flared opening. Nothing else is known of the breeding of this species.
The above is based on Weaver Wednesday, a weekly series about weaver species.
This species text first appeared as Weaver Wednesday [103]: Usambara Weaver on 2014-06-04
2. Breeding facts
Pair bond
no information
Breeding season
no information
Nest site
no information
Nest building
Nest resembles that of P. bicolor (made from dry tendrils and creepers), with shorter entrance tunnel and more flared opening. No other information
Colony size
no information
Clutch size
no information
Egg colour
no information
Egg size
no information
Incubation
no information
Chicks and nestling period
no information
Breeding information based on Handbook of the Birds of the World, Vol. 15.