Paul C. Cross Andrew P. Dobson Douglas W. Smith Matthew C Metz Daniel R. Stahler Peter J. Hudson Emily S. Almberg 2015 <p><span>Infection risk is assumed to increase with social group size, and thus be a cost of group living. We assess infection risk and costs with respect to group size using data from an epidemic of sarcoptic mange (</span><i>Sarcoptes scabiei</i><span>) among grey wolves (</span><i>Canis lupus</i><span>). We demonstrate that group size does not predict infection risk and that individual costs of infection, in terms of reduced survival, can be entirely offset by having sufficient numbers of pack-mates. Infected individuals experience increased mortality hazards with increasing proportions of infected pack-mates, but healthy individuals remain unaffected. The social support of group hunting and territory defence are two possible mechanisms mediating infection costs. This is likely a common phenomenon among other social species and chronic infections, but difficult to detect in systems where infection status cannot be measured continuously over time.</span></p> application/pdf 10.1111/ele.12444 en Blackwell Science Social living mitigates the costs of a chronic illness in a cooperative carnivore article