Age-specific survival and annual variation in survival of female chamois differ between populations

Abstract

In many species, population dynamics are shaped by age-structured demographic parameters, such as survival, which can cause age-specific sensitivity to environmental conditions. Accordingly, we can expect populations with different age-specific survival to be differently affected by environmental variation. However, this hypothesis is rarely tested at the intra-specific level. Using capture-mark-recapture models, we quantified age-specific survival and the extent of annual variations in survival of females of alpine chamois in two sites. In one population, survival was very high (>0.94; Bauges, France) until the onset of senescence at approximately 7 years old, whereas the two other populations (Swiss National Park, SNP) had a later onset (12 years old) and a lower rate of senescence. Senescence patterns are therefore not fixed within species. Annual variation in survival was higher in the Bauges (SD = 0.26) compared to the SNP populations (SD = 0.20). Also, in each population, the age classes with the lowest survival also experienced the largest temporal variation, in accordance with inter-specific comparisons showing a greater impact of environmental variation on these age classes. The large difference between the populations in age-specific survival and variation suggests that environmental variation and climate change will affect these populations differently.

Ageing with a silver-spoon: A meta-analysis of the effect of developmental environment on senescence

“…This is because if good environmental conditions during the first part of life (i.e., during development and early‐reproductive life) result in higher reproductive investment in early adult life, investment in late‐life reproduction should be reduced, potentially increasing the rates of reproductive senescence. In addition, if a correlation between developmental and late‐life environment was what was driving the effect of developmental environment on senescence, we would expect to see a significant effect in survival senescence rates (Reichert et al ; Bleu et al ; Le Coeur et al ; Péron et al ), in addition to the observed effect on reproductive senescence rates.…”

Trade‐offs between age‐related breeding improvement and survival senescence in highly polygynous elephant seals: Dominant males always do better

“…No studies have explored the life‐history traits of adult male elephant seals using data that span several generations. Here, we study the relationship between current breeding social rank (breeding state at time t ) and survival, recruitment and future breeding success (at time t + 1; direct fitness traits sensu Bleu et al, ; Hamel et al, ). We assume that social rank correlates closely with breeding success because dominant breeders sire many more offspring than subordinates (see Hoelzel et al, ).…”

“…failed breeders or breeders cf. non-breeders; Bleu et al, 2015). Strong sexual selection leads to considerable rank-related skew in breeding success among males of polygynous species, with dominant breeders siring most offspring born into a population (Galimberti, Fabiani, & Sanvito, 2002).…”

“…No studies have explored the life-history traits of adult male elephant seals using data that span several generations. Here, we study the relationship between current breeding social rank (breeding state at time t) and survival, recruitment and future breeding success (at time t + 1; direct fitness traits sensu Bleu et al, 2015;Hamel et al, 2010).…”

Multi‐event capture‐recapture analysis in Alpine chamois reveals contrasting responses to interspecific competition, within and between populations

“…m SB ≠ m FB and/or ψ SB−SB ≠ ψ FB−SB ); (b) age at year t ; (c) red deer population size index at year t ; we added the yearly population counts as a covariate on mortality m and/or breeding probabilities ψ . When modelling age‐specific mortality probabilities, we considered the three age classes previously described in these populations (see Bleu et al., 2015 for a description of these age classes in the study areas): age class 1, age class 2–12 and age class >12 (Figure 2). Because the age class 1 brings together few kids (captured at different ages in their first year of life, and most often after the peak of juvenile mortality) and females of age 1 (Figure 2), mortality m 0−1 for this age class was likely underestimated.…”