Informations et ressources scientifiques
sur le développement des zones arides et semi-arides

Titre : Evaluating the success of phased-release reintroductions for captive-born cheetah (Acinonyx jubatus) in South Africa

Auteur : Muller, Allison Anne

Université de soutenance : Stellenbosch University

Grade : Master of Science (MScConsEcol ) 2022

Résumé
The global cheetah population has declined to an estimated 7,100 individuals, with half the global population currently found in southern Africa. Where natural metapopulation dynamics are no longer possible, human mediated gene flow is coordinated in the form of managed metapopulations. In 2011, the Endangered Wildlife Trust (EWT, South Africa) established a Cheetah Metapopulation Project (CMP) to ensure the genetic and demographic viability of cheetah on small, fenced reserves in South Africa. Research from the CMP indicates that a new source population is required to ensure new genetics enter the metapopulation as the current rate is below the required four individuals per year. A phased-release method, consisting of two distinct phases, allows for the reintroduction of captive-born cheetah into the cheetah metapopulation in South Africa. The limited research on the reintroduction of captive-born carnivore studies indicates that captive-born cheetah are able to express behaviour seen in wild-born cheetah. This study aimed to provide an evaluation of a phased-release methodology for the reintroduction of captive-born cheetah in South Africa. This was achieved by determining criteria to evaluate the behavioural, spatial, and foraging ecology of each captive-born cheetah at both an individual-level and a population-level to allow for comparisons with wild-born cheetah and other methods of captive release. Post-release movements were calculated at month intervals, using data from GPS collars and post-release monitoring data from October 2019 to August 2021. Home-range (95%) and home-range overlap estimates were established for all cheetah. Of the twelve cheetah released following the phased-release method, five individuals settled after an exploration period, while five other individuals were still in their exploration stage at the end of the current study. The twelve cheetah used all available habitat types at some point during their movements, and all females birthed their first litter within seven months post-release. Alterations to a male cheetah’s social group also caused a change in habitat utilisation. Nineteen different prey species were identified at kill sites and prey consumption estimates indicated that the majority of the cheetah were able to reach the monthly energy requirement, although excessive supplement feeding was provided unjustifiably for four individuals. Body condition scoring and monitoring of kill sites was dependant on consistent monitoring which, when compromised or inconsistent, proved to limit the accuracy of these criteria. The criteria used for the evaluation of behavioural, spatial, and foraging ecology, proved successful on an individual level, and indicated areas that needed further investigation. When applied to a population level, phased-release cheetah showed similar characteristics to those of wild-born cheetah. It is recommended that the evaluation of this phased-release method is continued over a longer time period to further determine the success of this release method.

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