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Caching in the presence of competitors: Are Cape ground squirrels (Xerus inauris) sensitive to audience attentiveness?

Abstract

When social animals cache food close to their burrow, the potential for an audience member to observe the event is significantly increased. As a consequence, in order to reduce theft it may be advantageous for animals to be sensitive to certain audience cues, such as whether they are attentive or not to the cache event. In this study, observations were made on three groups of Cape ground squirrels (Xerus inauris) in their natural habitat when they cached provisioned food items. When individuals cached within 10 m of conspecifics, we recorded the attentiveness (i.e. whether any audience members were orientated towards the cacher, had direct line of site and were not engaged in other activities) and identity of audience members. Overall, there was a preference to cache when audience members were inattentive rather than attentive. Additionally, we found rank effects related to cache avoidance whereby high-ranked individuals showed less avoidance to cache when audience members were attentive compared to medium- and low-ranked individuals. We suggest this audience sensitivity may have evolved in response to the difference in competitive ability amongst the ranks in how successful individuals are at winning foraging competitions. This study demonstrates that Cape ground squirrels have the ability to not only monitor the presence or absence of conspecifics but also discriminate individuals on the basis of their attentive state.

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Acknowledgments

We would like to thank Tim Clutton-Brock and the Kalahari Research Trust for support and access to work on the Kuruman River Reserve. This study would not have been possible without the logistical support from Dave Gaynor. We would like to thank the volunteers on the squirrel project for their help collecting the ad libitum data on the squirrels. Thanks must also be extended to Simon Townsend and Nicola Harrison for helpful comments on the manuscript. The maintenance of the study population and collection of basic data was financed by the Universities of Cambridge and Zurich. JS and MBM were both funded by the University of Zurich.

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Correspondence to Jamie Samson.

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All applicable international, national and/or institutional guidelines for the care and use of animals were followed. All procedures performed in studies involving animals were in accordance with the ethical standards of the institution [University of Pretoria Animal Ethics Committee (S4532-13) and in the approved permit (number: ECO16-13)] at which the studies were conducted.

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The authors declare that they have no conflict of interest.

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Samson, J., Manser, M.B. Caching in the presence of competitors: Are Cape ground squirrels (Xerus inauris) sensitive to audience attentiveness?. Anim Cogn 19, 31–38 (2016). https://doi.org/10.1007/s10071-015-0910-0

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  • DOI: https://doi.org/10.1007/s10071-015-0910-0

Keywords

  • Audience effects
  • Attentiveness
  • Rank
  • Caching
  • Cape ground squirrel
  • Xerus inauris