Trophy hunting mediates sex-specific associations between early-life environmental conditions and adult mortality in bighorn sheep

1. Environmental conditions during early development, from conception to sexual maturity, can have lasting consequences on fitness components. Although adult lifespan often accounts for much of the variation in fitness in long-lived animals, we know little about how early environment affects adult lifespan in the wild, and even less about whether these effects differ between the sexes.
2. Using data collected over 45 years from wild bighorn sheep (Ovis canadensis), we investigated the effects of early environment on adult mortality in both sexes, distinguishing between natural and anthropogenic sources of mortality.
3. We used the average body mass of yearlings (at about 15 months of age) as a yearly index of environmental quality. We first examined sex differences in natural mortality responses to early environment by censoring harvested males in the year they were shot. We then investigated sex differences in the effects of early environment on overall mortality (natural and huntin...