Social living mitigates the costs of a chronic illness in a cooperative carnivore

Abstract 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 ( Sarcoptes scabiei ) among grey wolves ( Canis lupus ). We demonstrate that group s...

Full description

Bibliographic Details
Published in:Ecology Letters
Main Authors: Almberg, E. S., Cross, P. C., Dobson, A. P., Smith, D. W., Metz, M. C., Stahler, D. R., Hudson, P. J.
Other Authors: Festa‐Bianchet, Marco, National Science Foundation, National Park Service, U.S. Geological Survey, Yellowstone Park Foundation
Format: Article in Journal/Newspaper
Language:English
Published: Wiley 2015
Subjects:
Online Access:http://dx.doi.org/10.1111/ele.12444
https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fele.12444
https://onlinelibrary.wiley.com/doi/pdf/10.1111/ele.12444
https://onlinelibrary.wiley.com/doi/full-xml/10.1111/ele.12444
Description
Summary:Abstract 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 ( Sarcoptes scabiei ) among grey wolves ( Canis lupus ). 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.