Neighboring birds sing 'out of tune'
Great tits living next to each other may sing their songs at significantly different rates, more or less frequently, as compared to non-neighboring birds, according to a study published February 18, 2015 in the open-access journal PLOS ONE by Lysanne Snijders from Wageningen University, Netherlands and colleagues.
Great tits are territorial and use their song to signal their territory to unfamiliar potential competitors and familiar neighbors, where boundaries have likely already been established. To investigate how signal traits vary in relation to the overall social environment, the authors of this study tested whether neighboring birds sharing a territory boundary, rather than birds just flying in the area, is related to similarity in dawn song traits between territorial wild great tits. Researchers collected song recordings from over 70 unique male great tits at dawn, during the breeding season, and compared songs between neighbors and non-neighbors.
Scientists found that neighboring birds sang at significantly different rates-measured as songs per minute-compared to non-neighbors, where they found no effect of proximity on song rate similarity. The researchers suggest that the dissimilarity in dawn song rate between neighbors may either be the result of neighboring great tits actively avoiding similar song rates to possibly prevent interference, or just a result of one of the many factors birds use to select their territory. The authors conclude that great tit neighborhood structure is likely to be a relevant in shaping variation in territorial birdsong.