Black-capped chickadees, Poecile atricapillus, avoid song overlapping: evidence for the acoustic interference hypothesis

摘要: Many animals produce sounds that overlap the of others. In some animals, overlapping is thought to be an aggressive signal important in resource defence. Yet, can also occur by chance, and therefore its function controversial. this study, we conducted two experiments test black-capped chickadees, Poecile atricapillus. experiment 1, simulated territorial intrusions broadcasting songs inside established chickadee territories. Resident males overlapped playback-simulated intruders significantly less than expected as most species which has been described. Chickadees more when they were farther from intruder. This pattern suggests chickadees avoid a mechanism for reducing acoustic interference (‘interference avoidance hypothesis’). However, could constitute submissive signalling if de-escalation (associated with greater distance between opponents) through increasing rates (‘submissive Therefore, 2, contrasted these hypotheses comparing responses playback stimuli low or high potential value. We manipulated at different amplitudes. value either song stimuli, elicit aggression, white noise matching time-amplitude characteristics. If signal, then predicted would but not lack Contrary prediction, equally often, often chance. Furthermore, both types broadcast lower amplitudes (i.e. potential). Together, findings provide compelling evidence species, biotic abiotic interference.