The Utility of DNA Microsatellite Markers in Conservation of a Namibian Population of the Black Rhinoceros (Diceros Bicornis)

Abstract

Massive declines in the latter half of the 20th century left black rhinoceros populations perilously close to extinction with only approximately 3600 individuals remaining, in contrast to estimated census numbers of over 100,000 individuals in 1900. While Diceros bicornis bicornis is the second most abundant subspecies of black rhino, behind D. b. minor, relatively few genetic studies have focused on this taxon. I used polymorphic DNA microsatellite markers to describe population structure in this subspecies. Using these genetic markers, the goals of this study were: i) to characterize the genetic variability of D.b. bicornis individuals (n = 170) found in Etosha National Park, Namibia, using seven DNA microsatellite markers, ii) to determine if there is population structure within Etosha National Park, using both traditional Wright’s F-statistics and a Bayesian model that requires no a priori population assignment, iii) to determine relatedness amongst founding and newly introduced black rhinoceroses held in private game farms throughout Namibia, using moment estimators of relatedness; and iv) to determine parentage of game farm rhinos with partial or no pedigree data available, using likelihood-based methods. I found that: i) the levels of genetic diversity in D.b. bicornis from Etosha National Park are consistent with previously published studies using microsatellite markers, and are relatively high; ii) the population structure within Etosha National Park is ambiguous using traditional F-statistics, but can be subdivided into three diagnosable clusters (western, central and eastern) using a Bayesian approach; iii) a relatively high degree of relatedness exists among founding members of game farm rhinos; and iv) assignments of parentage had greater success when there were fewer candidate parents and support the notion that black rhinoceroses are polygynous.