WASHINGTON, Aug. 12 (UPI) -- U.S. researchers say they've found why older female cheetahs are rarely able to reproduce, a finding that could bolster genetic diversity among the big cats.
Scientists at the Smithsonian Conservation Biology Institute say a study of 34 cheetahs at eight institutions found that while the hormones and eggs of cheetahs older than 8 years appear normal, the animals' uterine tracts tend to suffer from abnormal cell growth, infections and cysts that prevent pregnancy.