Public Release:  'Mum! I'm hungry!' Hungry chicks have unique calls to their parents

BioMed Central

It can be hard to get noticed when you're a little chick in a big colony, but new research published in BioMed Central's open access journal BMC Ecology reveals that baby birds in need of a feed have individual ways of letting their parents know.

German and Swiss ornithologists studied the calls of chicks in a population of Jackson's golden-backed weaver birds on the shores of Lake Baringo in Kenya. Already knowing that parent birds can distinguish their own chicks from others by unique pattern changes in the frequency of their call, the researchers wondered how the parents could also tell if their own chick was hungry, and how hungry.

By temporarily removing chicks from their nests, the team set up cameras and microphones to record the chicks' behavior and begging calls. Lead researcher Hendrik Reers said, "Weaver bird chicks have two parts to their call; a "whistle-like" call followed by a "trill-like" call. In a non-hungry state, these parts of the call are slightly different from bird to bird,., and this allows the mother to identify their chicks. As the chicks get hungrier, as you might expect with any baby, the call gets louder and more energetic, but each bird still has a unique way of modifying their "normal" call to an "I'm hungry" call. These results imply that parents have to be familiar with their chicks' begging calls in order to estimate their hunger precisely."

The group found that the weaver bird chicks changed the length, pitch and amplitude of their begging calls, adding extra trills and shortening whistles. In fact, the hungrier a chick got, the more unique the call became. It seems that if you're a baby bird singing for your supper, the best way to make sure you get fed is to sing a different tune from everyone else!

###

Media Contact
Matt McKay
Head of Public Relations, BioMed Central
Tel: +44 (0) 20 3192 2216
Mob: +44 (0) 7825 257423
Email: matthew.mckay@biomedcentral.com

Notes to Editors

1. The effect of hunger on the acoustic individuality in begging calls of a colonially breeding weaver bird
Hendrik Reers and Alain Jacot
BMC Ecology (in press)

Please name the journal in any story you write. If you are writing for the web, please link to the article. All articles are available free of charge, according to BioMed Central's open access policy.

Article citation and URL available on request at press@biomedcentral.com on the day of publication.

2. BMC Ecology is an open access journal publishing original peer-reviewed research articles in environmental, behavioral and population ecology as well as biodiversity of plants, animals, and microbes.

3. BioMed Central (http://www.biomedcentral.com/) is an STM (Science, Technology and Medicine) publisher which has pioneered the open access publishing model. All peer-reviewed research articles published by BioMed Central are made immediately and freely accessible online, and are licensed to allow redistribution and reuse. BioMed Central is part of Springer Science+Business Media, a leading global publisher in the STM sector.

Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.