Experimental manipulation of mixed-species flocks reveals heterospecific audience effects on calling

摘要: Animal signallers are subject to audience effects when they alter communication due changes in the presence or characteristics of receivers. Studies aimed at understanding have typically examined conspecific audiences on signaller communication. Less work has focused heterospecific audiences, which present an important avenue research for species that participate mixed-species groups. Here we experimentally tested flocks Carolina chickadees, Poecile carolinensis, and tufted titmice, Baeolophus bicolor, effects. Birds were trapped from naturally occurring held seminatural outdoor aviaries, where recorded calling. We found chickadees titmice sensitive number conspecifics communicating via ‘chick-a-dee’ calls, social cohesion calls produced by both species. Chickadees also flocks, but chick-a-dee calling behaviour did not differ with regard flocks. Furthermore, playbacks simulated risk, more a flock. After these playbacks, fewer increasing numbers whereas These results suggest factors within their communicating, appear than do titmice. this is dominance status dominant over chickadees.