ORIGINAL PAPER Behavioural correlates of urbanisation in the Cape ground squirrel Xerus inauris Tarryn Chapman & Tasmin Rymer & Neville Pillay Received: 28 May 2012 / Revised: 15 September 2012 / Accepted: 18 September 2012 / Published online: 30 September 2012 # Springer-Verlag Berlin Heidelberg 2012 Abstract Urbanisation critically threatens biodiversity be- cause of habitat destruction and novel selection pressures. Some animals can respond to these challenges by modifying their behaviour, particularly anti-predator behaviour, allow- ing 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 sum- mer at each locality. As expected, ground squirrels in urban- ised areas were less vigilant and had shorter FIDs but did not trade-off between foraging and vigilance. In contrast, a popu- lation in a non-urbanised locality showed greater levels of vigilance, FID and traded-off vigilance and foraging. A pop- ulation 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. Keywords Anti-predator behaviour . Behavioural modifications . Behavioural plasticity . Cape ground squirrel . Urbanisation . Xerus inauris Introduction Urbanisation is a critical threat to biodiversity and is likely to continue to be so into the future (Davis 1976; Chase and Walsh 2006; McKinney 2006). Defined as the transforma- tion of rural/natural-formed landscapes into urban ones through the complex interaction of various processes (e.g. spatial diffusion, physical planning and landscape geogra- phy; Antrop 2000), urbanisation results in fragmentation of the natural habitat and ultimately impacts the biodiversity and ecology of an area (Devictor et al. 2006; Shochat et al. 2006). Yet, some species can thrive in urban areas, and their ability to do so is dependent on species-specific traits, which enable them to track human-induced changes by evolving new characteristics or enhancing pre-existing adaptations (Sih et al. 2011). The ability of a species to succeed in urban environments might depend on whether it can respond behaviourally to change (Watson 2009; Magle and Angeloni 2010), with species that display behavioural plasticity having a particu- lar advantage (Sih et al. 2011). Such plasticity might man- ifest in anti-predator behaviour which is likely to decrease in species living in urban areas, either because animals living in urban areas habituate to the presence of people (the habituation hypothesis; Watson 2009; Magle and Angeloni 2010) or because they respond to the absence of natural predators (McKinney 2002; Shochat et al. 2006). It is often difficult to tease apart these effects because urbanisation generally decreases natural predator abundance. However, although natural predators might be extirpated through the process of urbanisation, domestic predators, such as dogs Communicated by: Sven Thatje T. Chapman : T. Rymer : N. Pillay (*) School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Private Bag 3, Wits, Witwatersrand 2050, South Africa e-mail: Neville.Pillay@wits.ac.za Present Address: T. Rymer School of Marine and Tropical Biology, Faculty of Science and Engineering, James Cook University, PO Box 6811, Cairns, QLD 4870, Australia Naturwissenschaften (2012) 99:893–902 DOI 10.1007/s00114-012-0971-8