Both as co-first authors.
One size fits all: Eurasian lynx females share a common optimal litter size
Article first published online: 16 JUL 2013
© 2013 The Authors. Journal of Animal Ecology © 2013 British Ecological Society
Journal of Animal Ecology
Volume 83, Issue 1, pages 107–115, January 2014
How to Cite
Gaillard, J.-M., Nilsen, E. B., Odden, J., Andrén, H., Linnell, J. D. C. (2014), One size fits all: Eurasian lynx females share a common optimal litter size. Journal of Animal Ecology, 83: 107–115. doi: 10.1111/1365-2656.12110
- Issue published online: 18 DEC 2013
- Article first published online: 16 JUL 2013
- Manuscript Accepted: 3 JUN 2013
- Manuscript Received: 13 DEC 2011
- ITTECOP research programme
- Telemark counties
- Swedish Environmental Protection Agency
- Swedish Association for Hunting and Wildlife Management
- Norwegian Directorate for Nature Management
- Norwegian Research Council
- Regional Management Board from Region 2, 3 and 4 (Norway)
- the offices of Environmental Affairs in Hedmark, Oslo
- environmental stochasticity;
- individual optimization;
- Lack clutch size;
- life-history evolution;
- reproductive tactic
- Lack proposed that the average clutch size of altricial species should be determined by the average maximum number of young the parents can raise such that all females in a given population should share a common optimal clutch size. Support for this model remains equivocal and recent studies have suggested that intra-population variation in clutch size is adaptive because each female has its own optimal clutch size associated with its intrinsic ability to raise offspring.
- Although Lack litter size and condition-dependent litter size are presented as two competing models, both are based on the concept of individual optimization. We propose a unified optimal litter size model (called ‘adaptive litter size’) and identify a set of conditions under which a common vs. a state-dependent optimal litter size should be observed.
- We test whether females of Eurasian lynx (Lynx lynx) have a common optimal litter size, or whether they adjust their litter size according to their state. We used a detailed individual-based data set collected from contrasting populations of Eurasian lynx in Scandinavia.
- Observed reproductive patterns in female lynx provide strong support for the existence of a common optimal litter size. Litter size did not vary according to female body mass or reproductive category, or among contrasted populations and years. A litter size of 2 was associated with a higher fitness than both smaller and larger litters, and thus corresponded to the ‘adaptive litter size’ for female lynx.
- We suggest that the reproductive pattern of female lynx might correspond to a risk avoidance tactic common to all individuals, which has evolved in response to strong environmental constraints generated by a highly unpredictable food supply during lactation.