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. / Thesis (Master, Biology) -- Queen's University, 2009-06-01 10:18:14.064

Between November 2002 and October 2006, blood samples were collected from 46 black rhinoceroses (Diceros bicornis) originating from various national parks and game reserves within South Africa. The samples were divided into two groups, based on the black rhinoceros subspecies from which they originated: twenty-eight (n = 28) of the samples originated from subspecies D. b. bicornis, and eighteen (n = 18) from subspecies D. b. minor. DNA was extracted; the V4 hypervariable region of the 18S rRNA gene amplified and subjected to the Reverse Line Blot (RLB) hybridization assay. The RLB results demonstrated the presence of either Theileria bicornis or Babesia bicornis in 9 of the 46 samples examined. A further three PCR products failed to hybridize with any of the Babesia or Theileria species-specific probes, and only hybridized with the Babesia/Theileria genus-specific probe, suggesting the presence of a novel species or variant of a species. Samples collected from black rhinoceroses originating from the more arid areas of South Africa, Tswalu Game Reserve and the old Vaalbos National Park, were found to be apparently free of T. bicornis and B. bicornis piroplasms. Based on these findings, it was concluded that B. bicornis and T. bicornis are relatively widespread in black rhinoceros populations in South Africa and pose a potential risk to the success of metapopulation management programs. Of the two black rhinoceros subspecies that occur in South Africa, D. b. bicornis is at greater risk due to their apparently Babesia/Theileria-naïve status in certain areas, when compared to the subspecies D. b. minor. Conservation managers need to carefully evaluate methods and procedures during the translocation of black rhinoceroses, especially when relocating from geographically and climatically diverse ecosystems and more so when dealing with the subspecies D. b. bicornis. Copyright / Dissertation (MSc (Veterinary Tropical Diseases))--University of Pretoria, 2009. / Veterinary Tropical Diseases / unrestricted

Captive-breeding has been identified as an integral part of the conservation of threatened species. The black rhinoceros (Diceros bicornis) as a species is currently listed by the IUCN as critically endangered (CR), while the white rhinoceros’s (Ceratotherium simum) current status is near-threatened (NT). Three African rhinoceros subspecies currently occur in captive populations in regional population management programmes, namely the South-central black rhinoceros (Diceros bicornis minor), the Eastern black rhinoceros (Diceros bicornis michaeli) and the Southern white rhinoceros (Ceratotherium simum simum). Concerns have been raised, however, that these populations are not self-sustainable. This study aims to analyze the demographic parameters that contribute to the growth rates of the global captive populations of African rhinoceros. The study sets out to determine if these global captive populations are currently self-sustaining, which demographic factors have the most influence on the population growth rates, and whether or not 50- and 100- year targets set for the captive African rhinoceros populations are attainable. Demographic data from 1 January 2010 until 31 December 2010 were analysed through population census, life table and age structure analyses. Two additional concerns, namely poor reproductive performance of the female F1 generation and male-biased birth sex ratios, were also assessed. The results indicate that the captive populations of D. b. minor and C. s. simum are not self-sustainable, with population growth rates (λ) of 0.98 and 0.99, respectively. Diceros bicornis michaeli is the only subspecies with a growing population, with a population growth rate of 1.02. Sensitivity analyses conclude that fecundity rates, and not mortality rates, are the limiting factor to population growth in all three subspecies. While lifetime reproductive success values for D. b. minor and C. s. simum captive-born females are far lower than those of the founder generation, several factors need further investigation to determine the true cause of this. Birth sex ratio analysis shows no significant difference from parity for both black rhinoceros subspecies, however, quadratic logit regression conducted on the white rhinoceros data indicated a statistically significant male-bias. In all three subspecies, no significant link was found between maternal age and the sex of the offspring. Overall, the results of this study show that the 50 year and 100 year targets set at the GCAP workshop in 1992 are achievable. However, D. b. minor will only be able to achieve the target population sizes with an increase in fecundity rate of around 170% or alternatively, additional supplementation from the wild. Recommendations for the future include a global study of breeding husbandry at an institutional level, and the formalisation of a Global Species Management plan for D. b. minor. / Dissertation (MSc)--University of Pretoria, 2014. / I would like to acknowledge several organisations and people that have supported me throughout this MSc. The National Research Foundation (NRF), which provided me with the funding for my studies. My employer, The National Zoological Gardens of South Africa, a research facility of the NRF, and particularly the CEO, Dr Clifford Nxomani and my manager, Dr Abeda Dawood, who gave me support, encouragement and most importantly, time off to concentrate on this thesis. A special heartfelt thanks goes to my supervisors, Prof. Chris Chimimba, who never gave up on me, even though this study took a little bit longer than it was supposed to, and Dr Ed Stam, whose dedication, patience and endless comments (and good cappuccinos) helped shape this thesis. Lastly, my husband David, who always encourages me to do better and never allows me to become complacent; thank you, my love, for always pushing me to achieve. / Zoology and Entomology / MSc / Unrestricted

Black rhinoceroses (Diceros bicornis) have been extirpated from most of their historic range with the remaining individuals (ca. 5200) living in geographically isolated populations. Management priorities include creating new populations whilst maintaining genetic diversity and promoting gene flow between existing isolated populations. Such objectives are however currently hindered by a lack of comparative/reference data on levels of diversity, relatedness and inbreeding in a large, free-ranging black rhinoceros population. Here I attempt to address this gap in our knowledge by investigating the genetic diversity of the black rhinoceros Diceros bicornis minor within Kruger National Park (the largest free-ranging population of this subspecies) using nuclear and mitochondrial DNA. I compared the diversity of this founded population with the two source populations (KwaZulu-Natal, South Africa and Zimbabwe) using published studies, and evaluate the relative contribution of source lineages relative to the proportion of original founders. Analysis of the mtDNA control region revealed four haplotypes, with moderate haplotype and nucleotide diversity (h=0.48 (± 0.05 SD); π= 0.29%). Data from 13 microsatellite loci revealed moderate to high levels of genetic variation (number of alleles = 4.92 ± 0.90, effective number of alleles = 2.26 ± 0.25, observed heterozygosity = 0.50 ± 0.04, expected heterozygosity = 0.51 ± 0.04), low mean pairwise relatedness (r = -0.03), a low inbreeding coefficient (Fis = 0.04) and no evidence of genetic structuring. Diversity levels within the Kruger black rhinoceros population were high compared to levels reported in black rhinoceroses originating in KwaZulu-Natal and similar to those reported in individuals originating in Zimbabwe. Results show that 40-60% of the Zimbabwean lineages are represented in the Kruger population which is a noticeable increase in the relative contribution of the Zimbabwe founder population. The data provided by this study can be used to guide management and conservation decisions regarding maximising genetic variability across the subspecies. Furthermore, given the encouraging levels of genetic diversity observed, the Kruger black rhinoceros population would be an ideal source population for supplementation of genetically depauperate populations or creating new populations. Finally, these findings demonstrate a positive outcome in mixing the KwaZulu-Natal and Zimbabwe gene pools, with evidence that the founder Kruger black rhinoceros population has been genetically rescued from the low diversity seen in the KwaZulu-Natal black rhinoceroses in South Africa.

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