Le succès reproducteur au début de la vie, la longévité et le succès reproducteur tardif chez la femelle de la chèvre de montagne

Authors: Panagakis, Andrea
Advisor: Côté, Steeve D.
Abstract: The life-history theories of aging, which describe the mechanisms underlying age-related physiological declines, predict lifetime trade-offs between early reproductive allocation and latelife survival, reproduction, or both components of fitness. Recent studies in wild populations have found evidence for these early-late life trade-offs, but rarely across multiple traits while exploring the additional effects of variation in environmental conditions and individual quality. Benefiting from 27 years of longitudinal data from monitoring adult female mountain goats (Oreamnos americanus) at Caw Ridge, Alberta, we investigated the influence of age at first reproduction (AFR) and early reproductive success (ERS) on longevity and late reproductive success, while accounting for the influence of natal environmental conditions and individual quality. Contrary to our predictions, we did not find evidence for early-late life trade-offs in this population. AFR and ERS instead had positive but weak direct effects on late reproductive success. Population density in the year of a female's birth strongly reduced late reproductive success both directly and indirectly through AFR and ERS. The sole determinant of female longevity was the direct, negative effect of density. As predicted by previous studies in this population, high-quality females had a higher ERS compared to low-quality females. The results of this investigation provide an integrated picture of early-late life trade-offs, underscoring the importance of accounting for environmental conditions due to their potentially strong implications for population dynamics.
Document Type: Mémoire de maîtrise
Issue Date: 2016
Open Access Date: 24 April 2018
Permalink: http://hdl.handle.net/20.500.11794/26943
Grantor: Université Laval
Collection:Thèses et mémoires

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