Among wild mammals too, females live longer

In all human populations, average lifespans are longer for women than for men. Moreover, nine out of ten supercentenarians—that is, people 110 years old and up—are women. But what about for other mammals, in the wild? A team led by Jean-François Lemaître, a CNRS researcher at the Biometry and Evolutionary Biology laboratory (CNRS / Claude Bernard Lyon 1 University / VetAgro Sup), compiled demographic data for 134 populations of 101 mammalian species—from bats to lions, orcas to gorillas—making their study the widest reaching and most precise to date. In 60% of the cases, female mammals live longer than males: 18.6% longer on average (versus only 7.8% longer in humans). Is this because male mortality rates rise faster with age? Not necessarily, according to Lemaître’s team: for about half of the populations studied, the rise in mortality with age is even more pronounced among female mammals. However, mortality risk is lower among females at all ages.