An assessment of demographic parameters of African rhinoceros species (Diceros bicornis and Ceratotherium simum) and their significance to management in captivity

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dc.contributor.advisor Chimimba, Christian Timothy
dc.contributor.postgraduate Rehse, Tracy
dc.date.accessioned 2021-05-04T11:13:05Z
dc.date.available 2021-05-04T11:13:05Z
dc.date.created 2014
dc.date.issued 2014-01
dc.description Dissertation (MSc)--University of Pretoria, 2014. en_ZA
dc.description.abstract 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. en_ZA
dc.description.availability Unrestricted en_ZA
dc.description.degree MSc en_ZA
dc.description.department Zoology and Entomology en_ZA
dc.description.sponsorship 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. en_ZA
dc.identifier.citation Rehse, T 2014, An assessment of demographic parameters of African rhinoceros species (Diceros bicornis and Ceratotherium simum) and their significance to management in captivity, MSc Dissertation, University of Pretoria, Pretoria, viewed yymmdd <http://hdl.handle.net/2263/79770> en_ZA
dc.identifier.other M14/9/210 en_ZA
dc.identifier.uri http://hdl.handle.net/2263/79770
dc.language.iso en en_ZA
dc.publisher University of Pretoria
dc.rights © 2019 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria.
dc.subject Diceros bicornis minor en_ZA
dc.subject Diceros bicornis michaeli en_ZA
dc.subject Ceratotherium simum simum en_ZA
dc.subject Global captive population sustainability en_ZA
dc.subject Demographic analysis en_ZA
dc.subject Target population size en_ZA
dc.subject F1 female reproductive performance en_ZA
dc.subject UCTD
dc.title An assessment of demographic parameters of African rhinoceros species (Diceros bicornis and Ceratotherium simum) and their significance to management in captivity en_ZA
dc.type Dissertation en_ZA


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