O' Mother Where Wert Thou? Maternal Strategies in the Southern Elephant Seal: a Stable Isotope Investigation
International audience Maternal effects are widespread in ecology and can alter the dynamics of a population. We investigated the impact of maternal foraging strategies on offspring weaning mass, a proxy of maternal foraging success and of offspring survival, in Southern Elephant Seals on îles Kergu...
Published in: | Proceedings of the Royal Society B: Biological Sciences |
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Main Authors: | , , , , |
Other Authors: | , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
HAL CCSD
2012
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Subjects: | |
Online Access: | https://hal.archives-ouvertes.fr/hal-00671325 https://doi.org/10.1098/rspb.2012.0199 |
Summary: | International audience Maternal effects are widespread in ecology and can alter the dynamics of a population. We investigated the impact of maternal foraging strategies on offspring weaning mass, a proxy of maternal foraging success and of offspring survival, in Southern Elephant Seals on îles Kerguelen. Using four years of data, we modelled pup weaning mass as a two-components mixture and used blood stable isotope values to discriminate between maternal foraging strategies previously identified from bio-logging studies. Carbon isotope ratio was a strong predictor of weaning mass, but the relationship was non-monotonic in contrast to a priori expectations. Females foraging in the Interfrontal Zone weaned pups with a smaller mass compared to females foraging in Antarctic waters. Pup mass was positively correlated with a proxy of global Primary Production in the Interfrontal Zone for small weanlings. Maternal effects, via a poor foraging efficiency in the 1970s, may help explaining the large population decrease observed at that time on îles Kerguelen because of an overall decrease in pup weaning mass, survival and subsequent recruitment. |
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