Bower location by the Spotted Bowerbird (Chlamydera maculata)

Abstract

This study records the spatial distribution of Spotted Bowerbird (Chlamydera maculata) bowers at a study site in central Queensland, and examines how vegetation characteristics, the location of conspecific's bowers and canopy architecture affect bower location. Bowers were preferentially situated in brigalow regrowth habitat, with a mean (± s.d.) nearest-neighbour distance of 1059 ± 516 m. Bowers were evenly spaced within the region of highest bower density (20 bowers), but not within the study area as a whole. Bush canopy above bowers was thicker, attenuated more light, and covered a greater area than that of randomly selected bushes. Bower location within a bush was associated with a narrow range of canopy heights. These results suggest that bower location is primarily determined by large-scale habitat preferences. Secondly, within suitable habitat, bower location is influenced by male-male interactions. At a third, finer scale, choice of bower site is strongly influenced by microhabitat preferences, specifically bush architecture. The possibility that displaying under bushes represents a strategy for minimising aerial predation, and/or enhancing the visual characteristics of display elements, is discussed.