Skylarks don’t talk to strangers…or wanderers

Bird songs are among the most complex and fascinating forms of animal communication. Tiny differences in bird songs can often result in “dialects”, where populations of the same species have slightly different variations on the same songs. In a study out today in Naturwissenschaften, ornithologists have taken it a step further. Some skylarks can not only differentiate among songs of neighboring  birds, but also match these songs with their territories and punish birds who stray from their own “property.”

Elodie Briefer, a postdoc at Queen Mary University of London, and her colleagues studied skylarks in fields surrounding the University of Paris. They found that familiar skylark neighbors are tolerated if they stay in their own territory, but — not surprisingly —  skylarks with songs they don’t recognize as from the area are attacked if they intrude too close to the nest.

But they also used playback experiments to observe the birds’ reactions when they heard the song of a familiar skylark from different directions. Neighboring birds who strayed from their own territories were also treated as intruders.

The songs of neighboring skylarks share more syllables with each other than with the songs of strangers. Briefer said in a statement:

This may have evolved because it is safer for the birds to live close together, but they need a way to keep intruders out. By sharing a local dialect in their song, they can keep an ear out for other birds that live nearby and kick any strangers out of the neighbourhood.

Read the full paper at Naturwissenschaften (subscription required for full text), and check out Briefer’s video below of skylarks responding to a stranger’s song.

Briefer, E., Aubin, T., & Rybak, F. (2009). Response to displaced neighbours in a territorial songbird with a large repertoire Naturwissenschaften, 96 (9), 1067-1077 DOI: 10.1007/s00114-009-0567-0