Cape Weaver

The Cape weaver is a stocky 17 cm long bird with streaked olive-brown upperparts and a long pointed conical bill. The breeding male has a yellow head and underparts, an orange face, and a white iris. The adult female has an olive-yellow head and breast, shading to pale yellow on the lower belly. The female's eyes are brown, but 19% have pale eyes in summer and thus eye colour alone cannot be used to determine the sex. Young birds are similar to the female.

Vocalizations. The song of the Cape weaver is a harsh, rather hysterical sizzle. The alarm call is a sharp double chip and the contact call is a harsh "azwit".

The Cape weaver is endemic to South Africa, Lesotho and Eswatini, occurring across much of the area excluding the Kalahari Desert from the Orange River in the Northern Cape south to the Cape of Good Hope then east to northern KwaZulu Natal and inland almost to Bloemfontein in the Free State. The Cape weaver occurs in open grassland, lowland fynbos, coastal thicket and farmland, so long as there is permanent water and trees. In the more arid, hotter regions it is restricted to upland areas and it never occurs in forest.

When not breeding the Cape Weaver forms flocks, and it congregates in large roosts throughout the year, these may be shared with other birds, including other species of weavers. In some areas they desert the breeding colonies, returning at the commencement of the following breeding season. Anting has been observed and these birds bathe, even in rain or mist.

Breeding. The Cape weaver is a polygynous, territorial colonial nester, each male may have up to 7 females in a single breeding season. The males normally form colonies of between 2 and 20 males. Each male builds multiple nests within a small territory, which he vigorously defends against other males. Females test the quality of the construction of the nest by pulling at material on the interior; if it is acceptable the female adopts a hunched posture to indicate her readiness to mate. The nest is built by the male in about a week, and is a kidney-shaped, fully waterproof construction made of broad strips of grass or reeds that are woven together. Once a female accepts the nest the male builds an entrance tunnel at its base, while she lines the inside of the nest with fine grass and feathers. …