The effect of hunger on the acoustic individuality in begging calls of a colonially breeding weaver bird

BMC Ecology

Research Article

Hendrik Reers¹  Alain Jacot² 

[1] Behavioural Ecology and Evolutionary Genetics Group, Max Planck Institute for Ornithology, D 82319, Seewiesen, Germany;Behavioural Ecology and Evolutionary Genetics Group, Max Planck Institute for Ornithology, D 82319, Seewiesen, Germany;Swiss Ornithological Institute, Field Station Valais, 3970, Salgesch, CH, Switzerland;

关键词: Discriminant Function Analysis;    Linear Mixed Effect Model;    Acoustic Parameter;    Call Parameter;    Individual Recognition;   

DOI  :  10.1186/1472-6785-11-3

 received in 2010-10-05, accepted in 2011-01-26,  发布年份 2011

来源: Springer

【 摘 要 】

BackgroundIn colonially breeding birds, the ability to discriminate between individuals is often essential. During post-fledging care, parents have to recognize their own offspring among many other unrelated chicks in the breeding colony. It is well known that fledglings and food-provisioning parents of many bird species use contact calls to convey their identity. These calls are also often used as hunger-related signals of need in young birds. Here, we investigate how such calls incorporate signals of need and at the same time act as reliable indicators of each chick's identity.ResultsIn a field study, we experimentally manipulated the hunger level of colonially breeding Jackson's golden-backed weaver (Ploceus jacksoni) nestlings close to fledging and investigated its effects on acoustic call parameters. Some acoustic parameters that were related to the time-frequency pattern showed high individuality and were largely unaffected by a nestling's state of hunger. However, the majority of call parameters were significantly affected by hunger. Interestingly, most of these acoustic parameters showed both consistent changes with hunger and high between-individual differences, i.e. potential for individual recognition.ConclusionThe results indicate that individual recognition processes can be based on static, hunger-independent call parameters, but also on dynamic hunger-related parameters that show high individuality. Furthermore, these signal properties suggest that the assessment of signals of need can be improved if the signal value is referenced to a chick's vocal spectrum.

【 授权许可】

CC BY   
© Reers and Jacot; licensee BioMed Central Ltd. 2011