Female mammals usually outlive males, but a 27-year study found the pattern was reversed among...

Female birds have shorter lifespans than male birds, researchers find Female mammals usually live longer than males, but a 27-year study of North American birds has found the opposite pattern in birds.Researchers at the University of California, Los Angeles (UCLA) analyzed more than 563,000 bird-banding records and found that adult female birds had a 12.4% lower survival rate than adult males across 35 bird species. The study, published in Proceedings of the Royal Society B, is the first large-scale research to examine differences in survival between male and female birds.On average, female birds lived for 1.36 years after reaching adulthood, while males lived for 1.61 years. The research was funded by the National Science Foundation."Female birds are generally studied less than males, so I wanted to focus on them," said Joanna Wu, a doctoral candidate in ecology and evolutionary biology at UCLA and the study's lead author. "As I read more studies, I noticed that females often had lower survival rates than males. I expected the opposite because males usually compete for mates and take more risks. These findings surprised me because females are essential for reproduction and keeping...