Phase-dependent climate-predator interactions explain three decades of variation in neonatal caribou survival

1. Climate can have direct and indirect effects on population dynamics via changes in resource competition or predation risk, but this influence can be modulated by density- or phase-dependent processes. We hypothesized that for ungulates, climatic conditions close to parturition have a greater influence on the predation risk of neonates during population declines, when females are already under nutritional stress triggered by food limitation. 2. We examined the presence of phase-dependent climate-predator interactions on neonatal ungulate survival by comparing spatial and temporal fluctuations in climatic conditions, cause specific mortality, and per capita resource limitation. We determined cause-specific fates of 1384 caribou (Rangifer tarandus) from 10 herds in Newfoundland, spanning more than 30 years during periods of numerical increase and decline, while exposed to predation from black bears (Ursus americanus) and coyotes (Canis latrans). 3. We conducted Cox proportional hazards ...