WILDLIFE

Herring decline, black bear trafficking, a retirement home for once-captive whales and more

THE AVERAGE PERCENTAGE

by which female wildlife outlive their male counterparts. The study’s authors analyzed data for more than 130 wild mammal populations and found the greatest longevity differences in common brushtail possums, lions, orcas, moose, greater kudu and sheep. Why do females live longer? The research points to a few possible answers: males put more energy into sexual characteristics, such as growing larger horns, leaving them susceptible to extreme environmental events. They also produce more androgens, male hormones that can impair immune defence. Surprisingly, the study found that males’ “riskier” behaviour relating to sexual competition for females did not make a big difference.