Conservation genetics of the black rhinoceros, Diceros bicornis bicornis, in Namibia

摘要

Poaching and habitat destruction across sub-Saharan Africa brought the black rhinoceros (Diceros bicornis) close to extinction. Over the past few decades, however, one of four subspecies, D. b. bicornis, has experienced a significant population increase as a consequence of its protection within Etosha National Park (ENP), Namibia. We report here on the level and spatial distribution of black rhinoceros genetic diversity within ENP. Using nine microsatellite loci, genetic variation was assessed from 144 individuals. Our results are consistent with the observation of lower levels of genetic diversity in D. b. bicornis, when compared to D. b. michaeli, but greater diversity when compared to D. b. minor. We also showed that ENP’s black rhino genetic diversity is well represented in Waterberg National Park, originally founded with ENP individuals. We found no genetic signature of a recent bottleneck in ENP, however, suggesting that the genetic diversity within ENP has not been adversely affected by the recent severe population decline. Using Bayesian clustering methods, we observed no significant population structure within ENP, but positive spatial genetic correlation is observed at distances up to 25 km. This relationship exists in females but not males, suggesting reduced dispersal among females, the first evidence of limited female dispersal or philopatry in any species of rhinoceros.