Nesting associations of small birds andPolybioides tabidus(Vespidae Epiponinae) in southern Cameroon

Abstract

Wasp nests of Polybioides tabidus, an Epiponinae, are frequently encountered in the south of Cameroon. We demonstrate here for the first time that they are attractive as a nesting site for several species of small birds. Anthreptes collaris, Lonchura poensis, Nigrita canicapilla, Platysteina cyanea and Ploceus ocularis nest in close proximity (less than 30 cm) to wasp nests. Larger bird species, such as Lanius collaris and Pycnonotus barbatus also nest in the vicinity of wasp nests, but at a distance greater than 75 cm. We conducted our survey of bird nests in relatively homogeneous mango and orange tree plantations in Yaoundé. Because the trees of these plantations were similar in age, size, stipe and foliage density, we were able to control for nest site characteristics other than the presence or absence of wasp nests. Mango trees with wasp nests were 3.3 times more likely to have bird nests than were trees without wasp nests. In this situation, the presence or absence of wasp nests in the trees constitutes the most important parameter of variability for birds' nesting. The presence of wasp nests results in the aggregation of bird nests of two, and occasionally three, species. There is a positive correlation between the size of the bird and the distance of its nest from the wasp nest. Larger bird species tend to be less involved in this type of association. A three-way nesting association of ants, wasps and birds was observed only once. The ant involved was Tetramorium aculeatum (Myrmicinae).