Mocking Birds songs

A team of US scientists has found that mockingbirds living in variable climates sing more elaborate songs. Complex tunes, sung by males to impress females, are likely to signal the birds' intelligence. Published in Current Biology, the findings suggest that females seek mates with superior singing skills - smart enough to survive harsh climes.

Carlos Botero, a researcher from the National Evolutionary Synthesis Center in North Carolina, led the study. He and his colleagues compared recordings of 29 species of mockingbird, studying patterns in their songs including the number of different notes, the number of syllables and the birds' abilities to mimic other sounds.