Early growth, dominance acquisition and lifetime reproductive success in male and female cooperative meerkats

Authors

  • Sinead English,

    Corresponding author
    1. Large Animal Research Group, Department of Zoology, University of Cambridge, Cambridge, UK
    • Correspondence

      Sinead English, Current address: Edward Grey Institute, Department of Zoology, University of Oxford, Oxford OX1 3PS, U.K. Tel: +44 (0) 1865 271203; Fax: +44 (0) 1865 271168; E-mail: sineadenglish@cantab.net

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  • Elise Huchard,

    1. Large Animal Research Group, Department of Zoology, University of Cambridge, Cambridge, UK
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  • Johanna F. Nielsen,

    1. School of Biological Sciences, Institute of Evolutionary Biology, University of Edinburgh, Edinburgh, UK
    2. Institute of Zoology, Zoological Society of London, London, UK
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  • Tim H. Clutton-Brock

    1. Large Animal Research Group, Department of Zoology, University of Cambridge, Cambridge, UK
    2. Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, South Africa
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Abstract

In polygynous species, variance in reproductive success is higher in males than females. There is consequently stronger selection for competitive traits in males and early growth can have a greater influence on later fitness in males than in females. As yet, little is known about sex differences in the effect of early growth on subsequent breeding success in species where variance in reproductive success is higher in females than males, and competitive traits are under stronger selection in females. Greater variance in reproductive success has been documented in several singular cooperative breeders. Here, we investigated consequences of early growth for later reproductive success in wild meerkats. We found that, despite the absence of dimorphism, females who exhibited faster growth until nutritional independence were more likely to become dominant, whereas early growth did not affect dominance acquisition in males. Among those individuals who attained dominance, there was no further influence of early growth on dominance tenure or lifetime reproductive success in males or females. These findings suggest that early growth effects on competitive abilities and fitness may reflect the intensity of intrasexual competition even in sexually monomorphic species.

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