Rapid environmental changes – in climate, land use, and biotic interactions – are accelerating species extinctions and extirpations globally. Identifying the drivers that threaten populations is essential for conservation yet can be difficult given the variable nature of an organism’s response to biotic and abiotic stressors. We analyzed a 13-year monitoring dataset to explore the demographic responses of fishers (Pekania pennanti) to rapid environmental change in the southern Sierra Nevada, California, USA. Fisher survival was sensitive to both biotic and abiotic factors, although the strength and direction of these effects were ultimately mediated by age and sex. Specifically, male survival was lower among young individuals and decreased with increasing temperatures, basal area of hardwoods, and fungi consumption. Female survival was resilient to age effects and diet yet increased with greater forest heterogeneity and decreased with increasing temperatures and snow depth. Our findings illustrate the importance of disentangling the effects of both intrinsic and extrinsic factors on survival, especially among species with distinct sexual or ontogenetic differences. As global drivers of environmental change intensify in strength and frequency, understanding these complex relationships will allow practitioners to best manage for population persistence of fishers and habitat resilience concurrently.