Cape Sparrows roosting in Cape Weaver nests in Cape Town

Abstract

Night checks were conducted at seven Cape Weaver Ploceus capensis colonies in Pinelands to determine if the rate at which other species used the nests for roosting increased as it became colder. Cape Sparrows Passer melanurus roosted in nests, but the number roosting did not increase as night temperatures dropped, probably as temperatures were cool but not extreme. Cape Weavers were found to roost in nests, and their numbers increased as the breeding season approached. There were more male than female weavers, suggesting that males secured their territories ahead of breeding. Usually sparrows and weavers roosted singularly per nest, but sometimes Cape Sparrow pairs were seen. This study shows that Cape Sparrows may roost in Cape Weaver nests more frequently than previously thought. Additional colonies were monitored in Rondebosch, where there was one record of two Cape Sparrows roosting in two Cape Weaver nests. No Cape Sparrows were found roosting in Southern Masked Weaver P. velatus nests in Rondebosch, although not all these nests were checked. Cape and Southern Masked Weavers were not found to roost in the Rondebosch nests until June. Weavers and sparrows roosted with the head facing the nest entrance, with one weaver facing the other way.