Weaver news

PAPER: Sociable Weavers and paper wasps

2012-10-22 (282)

Bologna MA, Bombi P, Pitzalis M, Turillazzi S. 2007. A previously unreported association between a social wasp and a social passerine bird. Tropical Zoology 20:211-214

Abstract. An unreported association between the primitive social wasp Belonogaster lateritia Gerstaecker 1857 (Hymenoptera Vespidae) and the social bird Philetarius socius (Latham 1790) (Aves Ploceidae) is recorded. This association was observed only on active bird nests in a savannah area of central Namibia. On 25 checked nests, it was recorded on 5 of 5 active nests and 0 of 7 abandoned nests in savannah vegetation, never in desert areas. The wasp uses the inferior side of the bird nest aggregation, where tunnels open, as a substrate to fix the nest peduncle. The social and complex nests of P. socius are interpreted as an adaptive behaviour to reduce predation, and the presence of an aggressive associate wasp increases the defence against predators. The advantage for the wasp, besides the use of the substrate, could be the easiness of predation on flies attracted under the nest by the store of bird faeces.

This paper provides details of a survey of paper wasps suspended from Sociable Weaver nests, performed in 2004 and 2005. The 2004 survey was conducted in the Khomas and Hardap regions of Namibia. The 2005 survey was performed in September in the Luderitz, Ketmanshoop, Karas districts in Namibia and in Namaqualand and Bushmanland in South Africa.

Of course, this association was not unreported at the time of this paper (as claimed), although the earlier references were not in peer-reviewed journals. For instance:

Collias NE, Collias EC. 1964. Evolution of nest building in weaverbirds (Ploceidae).University of California Publications in Zoology 73:1-239 [reference to record by JT Emlen in 1953]

Anderson MD. 1994. First record of Sociable Weavers nesting in an exotic tree. Birding in Southern Africa 47: 20 [photo]

Oschadleus HD. 2000. First bird-ringing course held at Witsand Reserve. Bird Numbers 9(1):14

Photo (above): paper wasp nests on Sociable Weaver nest, from phown 1555.

Literature as featured in Weaver Watch news items