Do male black-capped chickadees eavesdrop on song contests? A multi-speaker playback experiment

Within a network of communicating individuals, animals may gather information about the relative quality of conspecics by eavesdropping on their signalling interactions. For territorial male songbirds, eavesdropping may be a low-cost, low-risk method for assessing the relative quality of the males around them. We used a three-speaker playback design to evaluate whether male black-capped chickadees (Poecile atricapillus) respond differently to two simulated countersinging intruders who differ only in relative features of their singing performance. We arranged three loudspeakersin an equilateraltriangle at the center of playback subjects’ territories.After luring males to the first loudspeaker by broadcasting non-song vo- calizations, we played songs from the remaining loudspeakers to simulate a countersinging