In the first part of the series, "To Fly or Not to Fly," David Attenborough travels around the world to seek evidence for the evolution of ... audio featured in the Bird Songs area.

In recent years this has led to some eye-opening revelations about monogamy and infidelity in the animal world -- particularly in birds ... a larger repertoire of songs, which have been shown ...

Why do no two bird songs sound the same? Evolution, Dianne Brunton, Auckland professor of biological sciences and birdsong expert says. Brunton has made a study of honeyeaters in New Zealand ...