Male black-capped chickadees begin dawn chorusing earlier in response to simulated territorial insertions

Abstract

Variation in the level of competition for mates and territories is likely to influence the behaviour of competitors. The start of the dawn chorus in songbirds is influenced by a variety of internal factors (e.g. circadian rhythms) and external factors (e.g. light levels, social cues). Here we investigate whether the start time of the dawn chorus is influenced by the singing behaviour of conspecific competitors. Using an Acoustic Location System, we recorded the dawn chorus in neighbourhoods of 5e10 blackcapped chickadees, Poecile atricapillus. We used playback to simulate an unfamiliar male performing a dawn song bout within an existing male’s territory. Playback began 15 min before the earliest song