Winged impersonator investigated
Published 06/04/2010 | 06:47
New research into a songbird's gift for mimicry could help explain why some birds impersonate other species, scientists in Scotland have said.
A study of the bowerbird, better known for its elaborate mating rituals, found it learns its calls directly from the species being mimicked, rather than from other bowerbirds.
Scientists believe the discovery could shed light on how and why around 20% of songbirds have developed the ability to copy the sounds of other creatures.
Bowerbirds can mimic the calls of other birds, as well as other animal sounds and human voices but little is known about why they do it, and how they learn and expand their repertoire.
Laura Kelley, of the University of Edinburgh's school of biological sciences, travelled to Queensland, Australia, to research her PhD on the subject.
She recorded the sounds made by male spotted bowerbirds living wild in a national park. Analysis of their calls showed that birds living near each other had a similar repertoire of mimicry.
The birds' impersonations of two other species in the area, butcherbirds and kites, showed slight variations between each bowerbird's versions of the calls. The differences suggest the birds copied the original species and not their bowerbird neighbours.
Ms Kelley, who led the study by the universities of Edinburgh and St Andrews, said "surprisingly" little research has been done on the subject. She said: "This is one of the first studies to look at what a natural population of mimics is copying and where they might be copying it from.
"For hundreds of years people have looked at how birds learn their song, why birds learn their song and how it varies among individuals. Mimicry is, to my mind. a form of song learning, yet it's a relatively neglected area of research. It's quite impressive just how accurately they can copy sounds."
The research was published in the journal Biology Letters and was funded by the Natural Environment Research Council.