Overview
- The Science Advances study pooled life records for 528 mammal and 648 bird species in zoos, plus wild data for 110 species, to estimate adult life expectancy with standardized models.
- In zoos, female mammals averaged roughly a 12–16% adult life-expectancy advantage, while male birds averaged about 5–6%, with larger and more variable gaps in the wild.
- Mating systems and sexual selection—especially polygyny and male-biased size dimorphism in mammals, and greater monogamy in birds—consistently predicted which sex lives longer beyond sex-chromosome effects.
- Caregiving correlated with longevity in the caregiving sex, notably in primates, suggesting selection for survival where extended offspring dependence is common.
- Researchers note the patterns mirror humans, where women outlive men in nearly every country, and public-health experts point to modifiable behaviors—risk-taking, tobacco and alcohol use, sun protection, and preventive care—that could narrow the gap.