Abstract
Urbanisation critically threatens biodiversity because of habitat destruction and novel selection pressures. Some animals can respond to these challenges by modifying their behaviour, particularly anti-predator behaviour, allowing them to persist in heavily transformed urban areas. We investigated whether the anti-predator behaviour of the Cape ground squirrel Xerus inauris differed in three localities that differed in their level of urbanisation. According to the habituation hypothesis, we predicted that ground squirrels in urban areas would: (a) be less vigilant and forage more; (b) trade-off flight/vigilance in favour of foraging; and (c) have shorter flight initiation distances (FID) when approached by a human observer. Observations were made in winter and summer at each locality. As expected, ground squirrels in urbanised areas were less vigilant and had shorter FIDs but did not trade-off between foraging and vigilance. In contrast, a population in a non-urbanised locality showed greater levels of vigilance, FID and traded-off vigilance and foraging. A population in a peri-urban locality showed mixed responses. Our results indicate that Cape ground squirrels reduce their anti-predator behaviour in urban areas and demonstrate a flexible behavioural response to urbanisation.
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Acknowledgements
We thank Dominic Moss of the Johannesburg Zoo, Stefan Du Toit of Krugersdorp Nature Reserve and Claire Knoop of Madikwe Game Reserve for giving us permission to conduct our experiments at the respective localities. Morah-Leigh Cooper and Wesley and Melissa Neumann provided assistance and accommodation at Madikwe Game Reserve. Thank you to our field assistants. The comments by three anonymous reviewers improved the manuscript. Funding and animal ethics approval (ethics clearance No. 2012/33/2A) was obtained from the University of the Witwatersrand.
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Communicated by: Sven Thatje
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Chapman, T., Rymer, T. & Pillay, N. Behavioural correlates of urbanisation in the Cape ground squirrel Xerus inauris . Naturwissenschaften 99, 893–902 (2012). https://doi.org/10.1007/s00114-012-0971-8
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DOI: https://doi.org/10.1007/s00114-012-0971-8