Biologists discover birdlife barbershop quartet

University of St Andrews scientists have discovered the bird world’s very own ‘barbershop quartet’.

The team studied the song of plain- tailed wrens in Ecuador and found that the birds live in groups of up to seven, joining together to sing choruses, often continuously for up to two minutes at a time.

According to Professor Peter Slater, who has nearly 30 years’ experience studying bird song, “With the exception of humans, this must be one of the most complicated singing performances ever described in the animal kingdom”.

Dr Nigel Mann and Kimberly Dingess, together with Professor Slater, all from the School of Biology, made this startling find – published on-line in the Royal Society’s journal Biology Letters – as part of a larger study of 22 species of wren, funded by the Leverhulme Trust.

Listening to the song in the early morning in a bamboo forest near Quito, Professor Slater described what he heard as ‘mind-boggling’.

“It’s already known that some birds duet and that others sing in choruses but these wrens do both and, furthermore, the choruses are extraordinarily precise and well coordinated. The song consists of a series of four phrases which lasts two seconds and is repeated many times, ABCDABCD… All the males in a group sing A and C, all the females B and D and, despite the speed of the performance, the different phrases overlap hardly at all. But within a sex they all do exactly the same thing at exactly the same time, made more impressive by the fact that each bird has some 20 phrases of the two types, yet all choose the right phrase at the right time. They occasionally get it wrong, but not often!”

So, why do members of a group join to produce such a complex chorus? Professor Slater has two theories about the plain-tailed wrens: “Our hunch is that the wrens do this as joint territorial defence. The presence of several birds singing in a coordinated fashion is likely to be extremely intimidating as they all gather round an intruding wren singing together.

“Another possibility is that, because more than just the breeding pair are singing, it may help to synchronise the group’s breeding efforts. Groups like this tend to be parents and their previous offspring, which all combine to tend the current brood. While daylength helps to synchronise the breeding of birds in higher latitudes, near the equator it hardly changes. Maybe chorusing keeps them all in tune with each other.”

These hypotheses remain untested but the team plan further work on this species to understand its breeding system and the role within it of this remarkable song.

ENDS

Issued by Beattie Media On behalf of the University of St Andrews For more information, please contact Claire Grainger, Press Officer – 01334 462530, 07730 415 015 or [email protected]; Ref: press releases/peterslater View the latest University news at http://www.st-andrews.ac.uk

NOTE TO EDITORS

A jpeg photograph of 1. the bird, 2. its habitat and 3. a sound file are all available from Claire Grainger, University of St Andrews Press Officer on 01334 462530, 07730 415 015 or email cg24@st- andrews.ac.uk

Professor Slater is also available for interview – telephone direct on 01334 463500, 07871 268 707 or email [email protected]