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Song and female choice for extrapair copulations in the sedge warbler, Acrocephalus schoenobaenus

journal contribution
posted on 01.04.2007, 00:00 authored by R Marshall, Kate BuchananKate Buchanan, C Catchpole
Although 90% of passerine birds live in socially monogamous pair bonds, molecular studies have revealed that genetic polygamy occurs in 86% of surveyed passerines, because individuals engage in copulations outside the pair bond (extrapair copulations; EPCs). Most explanations for the occurrence of EPCs involve female gaining indirect benefits from the extrapair male. The sedge warbler is a socially monogamous species in which some offspring result from EPCs (8% in this study). Complex song is a sexually selected male trait used by females which select mates based on a variety of male qualities. We used microsatellite DNA profiling to detect extrapair young and assign paternity. ‘Good genes’ theory predicts that females should engage in EPCs with males of higher quality than their social mate, with resulting fitness benefits. Extrapair males had smaller song repertoires and smaller territories than the social mate. This apparent preference for small-repertoire males as extrapair mates conflicts with the predictions from previous studies of this species. Sudden cessation of song after pairing may mean that song cues are unavailable for later extrapair matings and females may switch to other cues. Such behaviour may lead to different patterns of female choice during social and extrapair mating in the sedge warbler. We conclude that multiple reasons underlie patterns of female choice in this species.

History

Journal

Animal behaviour

Volume

73

Issue

4

Pagination

629 - 635

Publisher

Baillière, Tindall and Cassell [etc.].

Location

London, England

ISSN

0003-3472

eISSN

1095-8282

Language

eng

Publication classification

C1.1 Refereed article in a scholarly journal

Copyright notice

2007, The Association for the Study of Animal Behaviour