dc.contributor.author |
Oosthuizen, Wessel Christiaan
|
|
dc.contributor.author |
Altwegg, Res
|
|
dc.contributor.author |
Nevoux, Marie
|
|
dc.contributor.author |
Bester, Marthan Nieuwoudt
|
|
dc.contributor.author |
De Bruyn, P.J. Nico
|
|
dc.date.accessioned |
2018-06-29T11:59:45Z |
|
dc.date.issued |
2018-06 |
|
dc.description |
Supplementary material: Appendix 1–4. |
en_ZA |
dc.description.abstract |
Early developmental conditions contribute to individual heterogeneity of both phenotypic traits and fitness components, ultimately affecting population dynamics. Although the demographic consequences of ontogenic growth are best quantified using an integrated measure of fitness, most analyses to date have instead studied individual fitness components in isolation. Here, we estimated phenotypic selection on weaning mass in female southern elephant seals Mirounga leonina by analyzing individual‐based data collected between 1986 and 2016 with capture–recapture and matrix projection models. In support of a hypothesis predicting a gradual decrease of weaning mass effects with time since weaning (the replacement hypothesis), we found that the estimated effects of weaning mass on future survival and recruitment probability was of intermediate duration (rather than transient or permanent). Heavier female offspring had improved odds of survival in early life and a higher probability to recruit at an early age. The positive link between weaning mass and recruitment age is noteworthy, considering that pre‐recruitment mortality already imposed a strong selective filter on the population, leaving only the most ‘robust’ individuals to reproduce. The selection gradient on asymptotic population growth rate, a measure of mean absolute fitness, was weaker than selection on first‐year survival and recruitment probabilities. Weaker selection on mean fitness occurs because weaning mass has little impact on adult survival, the fitness component to which the population growth of long‐lived species is most sensitive. These results highlight the need to interpret individual variation in phenotypic traits in a context that considers the demographic pathways between the trait and an inclusive proxy of individual fitness. Although variation in weaning mass do not translate to permanent survival differences among individuals in adulthood, it explains heterogeneity and positive covariation between survival and breeding in early life, which contribute to between‐individual variation in fitness. |
en_ZA |
dc.description.department |
Mammal Research Institute |
en_ZA |
dc.description.department |
Zoology and Entomology |
en_ZA |
dc.description.embargo |
2019-06-01 |
|
dc.description.librarian |
hj2018 |
en_ZA |
dc.description.sponsorship |
The Dept of Science and Technology of South Africa provided funding through the National Research Foundation (NRF). |
en_ZA |
dc.description.uri |
http://www.oikosjournal.org |
en_ZA |
dc.identifier.citation |
Oosthuizen, W.C., Altwegg, R., Nevoux, M. et al. 2018, 'Phenotypic selection and covariation in the life-history traits of elephant seals : heavier offspring gain a double selective advantage', Oikos, vol. 127, no. 6, pp. 875-889. |
en_ZA |
dc.identifier.issn |
0030-1299 (print) |
|
dc.identifier.issn |
1600-0706 (online) |
|
dc.identifier.other |
10.1111/oik.04998 |
|
dc.identifier.uri |
http://hdl.handle.net/2263/65269 |
|
dc.language.iso |
en |
en_ZA |
dc.publisher |
Wiley |
en_ZA |
dc.rights |
© 2017 The Authors. Oikos 2017 © Nordic Society Oikos. This is the pre-peer reviewed version of the following article : 'Phenotypic selection and covariation in the life-history traits of elephant seals : heavier offspring gain a double selective advantage', Oikos, vol. 127, no. 6, pp. 875-889, 2018, doi : 10.1111/oik.04998. The definite version is available at : http://www.oikosjournal.org. |
en_ZA |
dc.subject |
Early conditions |
en_ZA |
dc.subject |
Individual heterogeneity |
en_ZA |
dc.subject |
Phenotypic selection |
en_ZA |
dc.subject |
Environmental variation |
en_ZA |
dc.subject |
Heterogeneity |
en_ZA |
dc.subject |
Individual fitness |
en_ZA |
dc.subject |
Body size |
en_ZA |
dc.subject |
Temporal variation |
en_ZA |
dc.subject |
Population |
en_ZA |
dc.subject |
Elephant seal (Mirounga leonina) |
en_ZA |
dc.subject |
Capture–recapture models |
en_ZA |
dc.title |
Phenotypic selection and covariation in the life‐history traits of elephant seals : heavier offspring gain a double selective advantage |
en_ZA |
dc.type |
Postprint Article |
en_ZA |