Oecologia. 2016 Jul;181(3):795-807. doi: 10.1007/s00442-016-3597-2. Epub 2016 Mar 11.
- 1Centre
d'Écologie et des Sciences de la Conservation (CESCO UMR 7204),
Sorbonne Universités, MNHN, CNRS, UPMC, 43 rue Buffon, CP51, 75005,
Paris, France. christielecoeur@gmail.com.
- 2Centre
d'Écologie et des Sciences de la Conservation (CESCO UMR 7204), Sorbonne
Universités, MNHN, CNRS, UPMC, 43 rue Buffon, CP51, 75005, Paris,
France.
- 3Laboratoire d'Écologie Alpine, Université Grenoble Alpes, CNRS, Grenoble, France.
Abstract
Most
research on the demography of wild animal populations has focused on
characterizing the variation in the mortality of organisms as a function
of intrinsic and environmental characteristics. However, such variation
in mortality is difficult to relate to functional life history
components (e.g. reproduction, dispersal, hibernation)
due to the difficulty in monitoring biological processes at a
sufficiently fine timescale. In this study, we used a 10-year
individual-based data set with an infra-annual timescale to investigate
both intra- and inter-annual survival patterns according to intrinsic
and environmental covariates in an introduced population of a small
hibernating rodent, the Siberian chipmunk. We compared three distinct
periods related to particular life history events: spring reproduction,
summer reproduction and hibernation. Our results revealed strong interactions between intrinsic and temporal effects. First, survival of male chipmunks strongly decreases during the reproduction periods, while survival is high and equal between sexes during hibernation. Second, the season of birth affects the survival of juveniles during their first hibernation,
which does not have long-lasting consequences at the adult stage.
Third, at an inter-annual scale, we found that high food resource
availability before hibernation
and low chipmunk densities specifically favour subsequent winter
survival. Overall, our results confirm that the well-known patterns of
yearly and inter-individual variation of mortality observed in animals
are themselves strongly variable within a given year, suggesting that
they are associated with various functional components of the animals'
life history.
KEYWORDS:
Hibernation; Male-biased mortality; Mark-recapture; Seasonal survival; Tamias sibiricus
