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 [234] – Discovery [117]: Kilombero Weaver on 2016-12-07
1. Basic biology
Kilombero Weaver male, figure from PHOWN
Identification. The Kilombero Weaver adult male (photo) is bright yellow with a dark brown mask which may appear black from a distance. Females (below) and non-breeding males are dull coloured, with a buff eye-stripe and two-toned bill.
Distribution. The Kilombero Weaver is a range restricted species, endemic to the floodplain swamps along the Kilombero River in south-east Tanzania (see distribution map above from Birds of Africa).
This species is the newest weaver species known to science, being described as recently as 1990 by Neil and Liz Baker. Their paper provided the only published breeding information for the species.
Habitat. The Kilombero Weaver is found in seasonally flooded grasslands in river floodplains. It occurs in extensive riverside swamps with tall fringing beds of Phragmites reeds, generally away from trees. In December many birds in non-breeding plumage follow the Kilombero River downstream from the Ifakara ferry crossing.
Food. The Kilombero Weaver feeds on seeds. It forages by moving up and down grass stems, feeding at flowering and fruiting grass heads. Flocks also forage on the ground.
Kilombero Weaver female at nest, figure from PHOWN
Breeding. This species breeds in swamps fringed with tall Phragmites mauritianus, which is also used by Eastern Golden Weavers.
The Kilombero Weaver breeds in loose colonies which often overhang water and may have a few nests or up to 20 or 30 nests, but solitary nests also occur. It is probably polygynous. The nest is woven by the male, as an oval, with a semi-elliptical side entrance facing downwards. The nest is built of grass leaves and strips and lined with broader grass leaves.
The eggs (clutch 1-2) are uniform olive-brown to turquoise with light brown markings. Incubation and fledging periods are unknown.
Photo (left): female Kilombero Weaver at nest, from phown 1961 (see this record for a photo of the male at a nest).
The above is based on Weaver Wednesday, a weekly series about weaver species.
This species text first appeared as Weaver Wednesday [18]: Kilombero Weaver on 2012-10-17
2. Breeding facts
Pair bond
Probably polygynous
Breeding season
Dec-Feb
Nest site
attached by side to reed at point 2-3 m above ground (closer to water when habitat flooded)
Nest building
woven by male, after accepting nest, female apparently adds further material
Colony size
Colonial, with up to 30 nests together, but solitary nests also noted
Clutch size
1-2 eggs
Egg colour
olive-brown to turquoise with light brown markings
Egg size
mean of three eggs 20 x 13.9 mm
Incubation
no information
Chicks and nestling period
no information
Breeding information based on Handbook of the Birds of the World, Vol. 15.