According to a group of ornithologists headed by Dr Lysanne Snijders of Wageningen University, the Netherlands, 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.
Two female great tits. Image credit: Shirley Clarke / Fordingbridge Camera Club / CC BY-SA 3.0.
The great tit (Parus major) is a passerine bird in the family Paridae. These birds are found throughout most of Europe, in Central and Northern Asia, the Middle East, and parts of North Africa.
They 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, Dr Snijders and her colleagues conducted a long-term study on a population of great tits at Westerheide, the Netherland.
They 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.
The team collected song recordings from 72 unique male great tits at dawn, during the breeding season, and compared songs between neighbors and non-neighbors.
The 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 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 scientists said.
“Great tit neighborhood structure is likely to be a relevant in shaping variation in territorial birdsong.”
The results are published online in the open-access journal PLoS ONE.
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Snijders L et al. 2015. Song Trait Similarity in Great Tits Varies with Social Structure. PLoS ONE 10 (2): e0116881; doi: 10.1371/journal.pone.0116881
