Olive-headed Weaver Ploceus olivaceiceps

Identification. The Olive-headed Weaver is a miombo weaver typically seen foraging quietly in the canopy, and occurring in eastern Africa. The male Olive-headed Weaver is slender-billed with a distinctive golden crown, olive face, throat and upperparts, orange-chestnut lower throat and breast; the upperparts are plain, and wings and tail dark; and the eye is red.The female has a wholly olive head, and less chestnut on the breast. The juvenile is similar to the female but with a yellow chin and throat. The poorly-known Usambara Weaver is similar to this species, but their ranges do not overlap.

Distribution. The Olive-headed Weaver occurs in Tanzania, east Zambia, Malawi and Mozambique (see map above, based on Birds of Africa). The northern-most record (from Mwamazengu, Tanzania) is from as recently as 1998. The southern Mozambique population has been described as a subspecies but the description was based on inadequate comparative specimens, and thus the species is treated as monotypic.

The isolated population near Panda in southern Mozambique is separated by more than 600 km from any other known sites. There are about 100 pairs in the Panda area compared to a global population estimate of about 20000 pairs (1998). This species is near threatened, but the situation may worsen with increasing habitat loss.

Habitat. The Olive-headed Weaver inhabits mature miombo (Brachystegia) woodland where Usnealichen is abundant.

Food. The Olive-headed Weaver feeds on insects, including butterflies and moths, beetles, bugs, and small wasps. It forages on tree trunks, clinging to the bark, and moving along the under and upper surfaces of branches, probing almost entirely in lichens. It is usually solitary or found in pairs, even when foraging in mixed bird parties.

Breeding. The Olive-headed Weaver is a monogamous, solitary nester, and the pair remains together all year. The nest is constructed entirely of Usnea, and is always placed in a thick clump of lichen, using living strands growing on a branch as a basis. The nest is placed on the underside of a thick branch rather than the tips of twigs. The nest is sited 12-18 m above the ground, generally near the crown of a tree. A short spout is usually added to the nest, but some nests lack a spout. Both male and female build the nest.

Eggs are plain turquoise-blue. Incubation and feeding of chicks is by both sexes, but much more by the female in both cases. Bohm’s Flycatchers may breed in old Olive-headed Weaver nests.

Breeding season
Oct in Zambia, Sept-Oct in Malawi and Aug-Oct in Mozambique

Nest site
attached to branch being utilized as a base on underside of thick branches (not outer twigs), up to 18 m above ground and mostly near crown of tree

Nest building
built by both sexes

Colony size
Solitary nester

Clutch size
2-3 eggs

Egg colour
plain turquoise-blue or white

Egg size
average size of three eggs 20 x 15 mm (Malawi)

Incubation
incubation by both sexes, but male only occasionally sitting, no information on duration of incubation period

Chicks and nestling period
chicks fed by both sexes, female contributing more than male, no information on duration of nestling period