Endangered Greater One‐horned Rhinoceros Carry High Levels of Genetic Variation

The population of Rhinoceros unicornis in the Chitwan Valley, Nepal, was reduced to an estimated effective population size (N e of 21–28 individuals (60–80 total animals) in 1962. Protein electrophoresis shows that heterozygosity remains very high in this population (H o = 9.9%) despite its near extinction. We attribute this high heterozygosity to large N e 's prior to the population bottleneck, the recent occurrence of the bottleneck, and long generation time. These results illustrate the importance of considering historical demography and life history parameters when evaluating the possible genetic effects of bottlenecks in wild populations. They also offer support to recent arguments that the erosion of genetic diversity attributed to bottlenecks may be overemphasized.