White-browed Sparrow-weaver Plocepasser mahali
Uhuru Park, Nairobi, Kenya, November 2006

A large, chunky and aptly-named sparrow-like weaver, the White-browed Sparrow-weaver is an African endemic found in dry, acacia habitat from Somalia to South Africa. The birds usually occur in noisy groups, building very ragged, untidy roosting and breeding nests that typically look like they’ve been half-destroyed in a storm!

Much has been written about the nests of this sociable species, and the following is an online abstract taken from Condor, Vol. 91, No. 1 (Feb., 1989): “Group-living White-browed Sparrow-Weavers build their roost and breeding nests on one side of nest trees. The placement of nests correlates with the direction of the local prevailing wind. Birds gain a 35% increase in the useful life of a nest built on the leeward side of a nest tree, compared with a nest built on the windward side. Solar radiation, humidity, and thermal effects appear unimportant in influencing nest placement. Foliage density and other nearby cover does not affect nest placement. Hence, White-browed Sparrow-Weaver nest placement appears to be an adaptation for having large numbers of intact nests available for breeding and for roosting throughout the year.”