| Popis: |
Mediated by resource availability, acquisition and assimilation, body size is a key component of fitness. Growth traits directly influence survival and reproductive success, thus trade-offs between increases in structural growth or body reserves characterizes a nexus for maximizing fitness in environments with unpredictable periods of prey paucity. Phenotypic plasticity in growth and body condition enables organisms to cope with variable and finite resource environments, thereby influencing population persistence. Resource availability during early life can markedly influence lifetime patterns of growth, reproductive success, and survival, particularly for indeterminately growing ectotherms, which rely on both available resources as well as ambient temperatures to maximize fitness traits. We use a novel estimator of the von Bertalanffy growth model to analyze the effects of early life resource variation using 17 years of mark-recapture data from populations of western terrestrial garter snakes (Thamnophis elegans), which differ along a pace-of-life continuum into fast- and slow-living ecotypes. In contrast to fast pace-of-life animals, slow-living populations respond to stochastic variation in prey availability with lifetime growth that reflects their early-life prey environment—exhibiting compensatory strategies in both structural growth and body condition. Our findings highlight the importance of accounting for context-dependent early-life environments when evaluating population traits. |
