Predation risk and food: opposite effects on overwintering survival and onset of breeding in a boreal rodent
Article first published online: 11 JUN 2012
© 2012 The Authors. Journal of Animal Ecology © 2012 British Ecological Society
Journal of Animal Ecology
Volume 81, Issue 6, pages 1183–1192, November 2012
How to Cite
Haapakoski, M., Sundell, J. and Ylönen, H. (2012), Predation risk and food: opposite effects on overwintering survival and onset of breeding in a boreal rodent. Journal of Animal Ecology, 81: 1183–1192. doi: 10.1111/j.1365-2656.2012.02005.x
- Issue published online: 29 OCT 2012
- Article first published online: 11 JUN 2012
- Received 15 September 2011; accepted 30 April 2012 Handling Editor: Ims Rolf
- indirect predation;
- predator stress
1. In seasonal environments, optimal onset of breeding and survival plays major roles in individual fitness. Many physiological and behavioural factors related to breeding increase the risk of predation; thus, breeding decisions should be based on current risks and benefits. According to life-history theory, if current predation risk is high and breeding itself increases the risk, it may be beneficial to postpone breeding.
2. During winter in northern hemispheres, food availability is limited and is at its lowest just prior to the onset of breeding in spring. Food constraint may lead to poor condition and reduced ability to start breeding.
3. We studied the effects of food and predation risk on winter survival and onset of breeding in a common boreal rodent, the bank vole (Myodes glareolus). In a 2 × 2 factorial experiment, we manipulated food availability (food supplemented or not) and predation risk (presence/absence of predator odour) in 20 large outdoor enclosures in central Finland.
4. Survival probabilities were highest in no predation risk treatments, whereas they were lowest in the predator risk treatment. The same trend was observed in vole densities and the weight change in individuals. Voles with food addition bred earlier than in the other treatments.
5. We conclude that during energy constrained harsh conditions in winter, predation risk causes behavioural changes throughout the winter and has significant negative survival and fitness effects for small mammals, reflected as delay in the start of breeding.