Behavioral Ecology Advance Access originally published online on May 16, 2007
Behavioral Ecology 2007 18(4):716-724; doi:10.1093/beheco/arm035
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Activity patterns of urban red foxes (Vulpes vulpes) reduce the risk of traffic-induced mortality
a School of Biological Sciences, University of Bristol, Woodland Road, Bristol, BS8 1UG, UK b Environment Department, University of York, Heslington, York YO10 5DD, UK
Address correspondence to P.J. Baker, who is now at Plant Science Laboratories, School of Biological Sciences, University of Reading, Whiteknights, Reading, Berkshire RG6 6AS, UK. E-mail: p.j.baker{at}reading.ac.uk.
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Abstract |
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Traffic collisions can be a major source of mortality in wild populations, and animals may be expected to exhibit behavioral mechanisms that reduce the risk associated with crossing roads. Animals living in urban areas in particular have to negotiate very dense road networks, often with high levels of traffic flow. We examined traffic-related mortality of red foxes (Vulpes vulpes) in the city of Bristol, UK, and the extent to which roads affected fox activity by comparing real and randomly generated patterns of movement. There were significant seasonal differences in the number of traffic-related fox deaths for different age and sex classes; peaks were associated with periods when individuals were likely to be moving through unfamiliar terrain and would have had to cross major roads. Mortality rates per unit road length increased with road magnitude. The number of roads crossed by foxes and the rate at which roads were crossed per hour of activity increased after midnight when traffic flow was lower. Adults and juveniles crossed 17% and 30% fewer roads, respectively, than expected from randomly generated movement. This highly mobile species appeared to reduce the mortality risk of minor category roads by changing its activity patterns, but it remained vulnerable to the effects of larger roads with higher traffic flows during periods associated with extraterritorial movements.
Key words: aversive behavior, carnivora, dispersal, extra-territorial movements, habitat fragmentation, risk-sensitive behavior, urbanization.
Received 7 December 2006; revised 21 February 2007; accepted 27 March 2007.