Overview

• An international team reporting in Science Advances compared lifespans across 1,176 species—528 mammals and 648 birds—using data from the wild and from zoo records.
• On average, female mammals live about 12–13% longer than males, while in birds males live roughly 5% longer.
• The patterns persist in protected zoo settings, drawing on Species360 records, which strengthens the case for inherent biological influences.
• Researchers highlight sexual selection and caregiving roles as contributors, with male–male competition shortening male lifespans in many mammals and intensive maternal care correlating with longer-lived females.
• In humans, women outlive men in nearly every country, including a 5.8-year gap in the U.S. in 2021, and experts note the difference can be narrowed through preventive care, screening, and reducing risky behaviors.