Introduction

The Kilombero Weaver was first noticed by Eric Burnier, a Swiss physician and amateur naturalist, who worked at the Ifakara medical research station in Tanzania. The weaver was reasonably common in the area, but Burnier could not identify it, and so he mentioned it to the Bakers. During December 1986 Neil and Elizabeth Baker visited the town of Ifakara in Morogoro Region, east central Tanzania, mainly as a field trip for the Tanzanian Bird Atlas.

At the time of their visit, the weaver was breeding and male birds were easily located along the road to the nearby ferry at Kivukoni. The species was distinctive but could not be identified in the field. Five female and 2 male birds were caught in mist nets. One male and one female specimen were collected as types for a new species.

Subsequent visits to the site were made on 27 February 1987 and 2 April 1988. A further 12 males and 21 females were caught and measured. On 27 February 1987 two specimens were collected at Kivukoni for the University of Dar es Salaam.

The Bakers did not find any mixed species colonies with the Kilombero Weaver, and the closest known breeding weavers were small colonies of Eastern Golden Weavers nesting in bamboo in Ifakara township outside the swamp habitat 7 km away.

The Kilombero Weaver was first illustrated in the type description, by a colour plate of the male and female, and also a line drawing of a nest, and of the bill shapes of similar weavers.

Scientific citation

Meaning of names

First English name

Alternate names

Collector

Date collected

Locality collected

Type specimens

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 right 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.

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).