Mitigating human-caused mortality for large carnivores is a pressing global challenge
for wildlife conservation. However, mortality is almost exclusively studied at local
(within-population) scales creating a mismatch between our understanding of risk
and the spatial extent most relevant to conservation and management of wide-ranging
species. Here, we quantified mortality for 590 radio-collared mountain lions
statewide across their distribution in California to identify drivers of human-caused
mortality and investigate whether human-caused mortality is additive or compensatory.
Human-caused mortality, primarily from conflict management and vehicles,
exceeded natural mortality despite mountain lions being protected from hunting.
Our data indicate that human-caused mortality is additive to natural mortality as
population-level survival decreased as a function of increasing human-caused mortality
and natural mortality did not decrease with increased human-caused mortality.
Mortality risk increased for mountain lions closer to rural development and decreased
in areas with higher proportions of citizens voting to support environmental initiatives.
Thus, the presence of human infrastructure and variation in the mindset of
humans sharing landscapes with mountain lions appear to be primary drivers of risk.
We show that human-caused mortality can reduce population-level survival of large
carnivores across large spatial scales, even when they are protected from hunting.