Sex-specific associative learning cues and inclusive fitness benefits in the Seychelles warbler

Authors

  • D. S. Richardson,

    1. Department of Animal and Plant Sciences, University of Sheffield, Sheffield, UK
    2. Department of Animal Ecology, University of Lund, Lund, Sweden
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  • T. Burke,

    1. Department of Animal and Plant Sciences, University of Sheffield, Sheffield, UK
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  • J. Komdeur

    1. Animal Ecology Group, Centre for Evolutionary and Ecological Studies, University of Groningen, Haren, The Netherlands
    2. Department of Zoology, University of Melbourne, Victoria, Australia
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D. S. Richardson, Department of Animal Ecology, University of Lund, SE-223 62 Lund, Sweden.
Tel.: +46 46 2223613; fax: +46 46 2224716;
e-mail: david.richardson@zooekol.lu.se

Abstract

In cooperative breeding vertebrates, indirect fitness benefits would be maximized by subordinates that accurately assess their relatedness to group offspring and preferentially help more closely related kin. In the Seychelles warbler (Acrocephalus sechellensis), we found a positive relationship between subordinate-nestling kinship (determined using microsatellite marker genotypes) and provisioning rates, but only for female subordinates. Female subordinates that helped were significantly more related to the nestlings than were nonhelpers, and the decision to help appears to be based on associative learning cues. High levels of female infidelity means that subordinates cannot trust their legitimacy through the male line, consequently they appear to use the continued presence of the primary female, but not the primary male, as a reliable cue to determine when to feed nestlings. By using effective discrimination, female subordinates are able to maximize the indirect benefits gained within a cooperative breeding system otherwise driven primarily by direct breeding benefits.

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