Reproductive and genetic consequences of founding isolated lion populations

This study compared the outbred Serengeti lion population with the small, geographically isolated Ngorongoro Crater population, which descended from few founders and experienced inbreeding. The authors measured genetic markers alongside reproductive traits including semen quality and circulating reproductive hormones. The Crater lions showed reduced genetic variation and a higher incidence of abnormal sperm and lower testosterone, paralleling patterns documented in cheetahs. The work provided a clear natural experiment linking demographic isolation and inbreeding to measurable declines in male reproductive function. It strengthened the general argument that loss of genetic diversity carries reproductive costs in felids and informed management strategies aimed at maintaining gene flow among fragmented big-cat populations.