Survival, not reproduction, drives population growth of a neotropical mammal (Philander quica) in a seasonal environment

Abstract

Seasonality is a prevalent environmental feature in tropical forests and can shape the life history of organisms subjected to regular and periodic changes in temperature and rainfall. Tropical forest marsupials usually reproduce seasonally in response to limited productive periods. This seasonality in reproduction may have an impact on other vital rates and contribute differently to population growth rate (λ) in different seasons. Here, we employed a periodic matrix population model and elasticity analysis to assess the potential contribution of survival, maturation, and reproductive rates to λ in both dry and wet seasons for the marsupial Philander quica. Survival played a predominant role over reproduction in shaping population dynamics, with subadult and pouch young survival exhibiting critical roles in dry and wet seasons, respectively. Despite unpredictable environmental perturbations such as the La Niña phenomenon, the predominance of survival in driving population growth underscores the resilience of marsupial life histories and inherent constraints shaping evolutionary trajectories.