Forest harvest and natural stressors compound to reduce juvenile ungulate survival

Abstract Understanding how anthropogenic disturbances compound with natural stressors to influence wildlife survival, particularly during vulnerable life stages, is critical for conserving biodiversity and informing management decisions. Juveniles can be sensitive to disturbances, which possibly reduce their survival and lead to population declines. We monitored survival of 180 juvenile moose Alces alces from capture (7–8 months old) to recruitment at 18 months old in two anthropogenically disturbed systems in western Canada, where population declines coincided with extensive salvage logging following an insect outbreak. We investigated how juvenile use of forest harvest features influenced their mortality risk, and whether this risk was modified by body condition, long‐term use of forest harvest features, forage availability, weather or predation risk from wolves Canis lupus and black bears Ursus americanus . Juvenile survivorship was 0.59 (95% CI = 0.51–0.67). Wolf predation accounted for 55.1% of mortalities, followed by bears (14.5%), humans (14.5%), health‐related (10.1%) and cougars ( Puma concolor ) (5.8%). Juvenile moose use of forest harvest features—new cutblocks (0–8 years since harvest; hazard ratio [HR] = 1.29, 95% CI: 1.02–1.64) and higher road densities (HR = 1.44, 95% CI: 1.06–1.95)—reduced their survival, presumably from increased predator and hunter efficiency in these habitats. Older cutblocks did not impact juvenile survival (HR = 0.87, 95% CI: 0.69–1.09). Forest harvest appears inherently risky, regardless of predation risk, forage, weather, juvenile condition and long‐term use. However, juveniles with more winter ticks, Dermacentor albipictus (HR = 1.37, 95% CI: 1.08–1.73), and yearlings with lower weights at capture (HR = 0.32, 95% CI: 0.18–0.61) had heightened mortality risk, likely from increased vulnerability to predation. Synthesis and applications . Anthropogenic disturbances, such as forest harvest, create risky landscapes for juveniles by increasing their vulnerability to predation and hunting, and when combined with natural stressors like parasitism, likely drive population declines. Managing landscapes with a species‐centric approach that addresses the cumulative effects of human and natural stressors is essential to mitigate adverse impacts from resource extraction and support wildlife populations.