Alternative reproductive tactics in male Cape ground squirrels Xerus inauris

    Authors

    M. Scantlebury; J. M. Waterman;N. C. Bennett

    Comments

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    Abbreviated Journal Title

    Physiol. Behav.

    Keywords

    Cape ground squirrel; alternative reproductive tactic; resting metabolic; rate; cortisol; testosterone; luteinising hormone; vigilance; reproductive suppression; CRYPTOMYS DAMARENSIS COLONIES; MEERKATS SURICATA-SURICATTA; SUSTAINED; METABOLIC-RATE; DAMARALAND MOLE-RATS; GLUCOCORTICOID LEVELS; OXYGEN-CONSUMPTION; SPERM COMPETITION; SOCIAL-DOMINANCE; MATING SYSTEMS; EXOGENOUS GNRH; Psychology, Biological; Behavioral Sciences

    Abstract

    In some animal societies, males vary in the strategies and tactics that they use for reproduction. Explanations for the evolution of alternative tactics have usually focussed on extrinsic factors such as social status, the environment or population density and have rarely examined proximate differences between individuals. Anecdotal evidence suggests that two alternative reproductive tactics occur in cooperatively breeding male Cape ground squirrels. Here we show that there is strong empirical support for physiological and behavioural differences to uphold this claim. `Dispersed' males have higher resting metabolic rates and a heightened pituitary activity, compared with philopatric 'natal' males that have higher circulating cortisol levels. Dispersed males also spend more time moving and less time feeding than natal males. Additionally, lone males spend a greater proportion of their time vigilant and less of their time foraging than those that were in groups. The choice of whether to stay natal or become a disperser may depend on a number of factors such as age, natal group kin structure and reproductive suppression, and the likelihood of successful reproduction whilst remaining natal. Measuring proximate factors, such as behavioural and endocrine function, may provide valuable insights into mechanisms that underlie the evolution of alternative reproductive tactics. (C) 2008 Elsevier Inc. All rights reserved.

    Journal Title

    Physiology & Behavior

    Volume

    94

    Issue/Number

    3

    Publication Date

    1-1-2008

    Document Type

    Article

    Language

    English

    First Page

    359

    Last Page

    367

    WOS Identifier

    WOS:000256899500007

    ISSN

    0031-9384

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