Mark Keith
University of Pretoria
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Featured researches published by Mark Keith.
Oryx | 2011
Michelle Thorn; Matthew Green; Mark Keith; Kelly Marnewick; Philip W. Bateman; Elissa Z. Cameron; Dawn M. Scott
Accurate assessment of carnivore population status is frequently hindered by insufficient distribution data. For northern South Africa we address this deficit by mapping new records from landscape-scale sign surveys, questionnaire interviews, problem animal records and camera trapping. The black-backed jackal Canis mesomelas and caracal Caracal caracal remain common and wide- spread. Ranges of the serval Leptailurus serval and brown hyaena Hyaena brunnea were much larger than previous estimates, reducing the risk of simultaneous extirpation across all occupied locations. The proportion of range area occupied was larger for several species, notably the leopard Panthera pardus , cheetah Acinonyx jubatus and serval. We conclude that the serval continues to recover from historical threats and is expanding into new areas. A larger brown hyaena range and less fragmented pattern of occurrence probably confers greater resilience to threats than was suggested by previous data. Reduced extinction risk arising from the increased area occupied by the cheetah and leopard is tempered by probable local range contraction. Our maps provide baseline information for monitoring the distribution of these six species, which is essential in managing ecological issues that have a spatial component such as responses to changing land use. Our results also demonstrate the utility of detection/non- detection surveys in rapid assessment of carnivore populations at large spatial scales.
Animal Conservation | 2005
Mark Keith; C. T. Chimimba; Belinda Reyers; A.S. van Jaarsveld
The current study investigates whether a simple measure of taxonomic diversity (Taxonomic Distinctiveness (TD)) can be used as a proxy for different measures of phylogenetic diversity (Phylogenetic Distinctiveness (PD)) in determining species of regional conservation priority, and uses extant South African Chiroptera and Carnivora as a case study. Published phylogenies for the two mammalian Orders allowed the quantification of a node-based measure that was considered to represent phylogenetic diversity (PD NODE ), as well as a branch length-based measure that was considered to represent the amount of evolutionary change over time (PD BRANCH ). Both the PD NODE and PD BRANCH , together with TD were included in our regional conservation priority assessment. Although no statistically significant differences were detected between the PD NODE , PD BRANCH and the TD for both the Chiroptera and Carnivora, these measures were also shown to be correlated with each other. More importantly, inclusion of either the PD NODE , PD BRANCH , or TD in our analysis did not significantly alter the species that were identified as being of regional conservation priority. Both regional priority scores for the South African Chiroptera and Carnivora and their respective rankings were broadly consistent across the three potential indicators of conservation status utilised. These results suggest that the inclusion of either the PD NODE and/or PD BRANCH in conservation prioritisation exercises may not add value to that currently provided by the TD. Consequently, this implies that in the absence of relevant PD data, the utilisation of the TD in regional conservation priority settings may provide the appropriate information on evolutionary diversity.
European Journal of Wildlife Research | 2015
Sze-Wing Yiu; Mark Keith; Leszek Karczmarski; Francesca Parrini
Reintroductions have been increasingly used in carnivore conservation. Animal movement influences fitness and survival and is the first behavioural response of reintroduced animals to ‘forced dispersal’ in a new habitat. However, information available on early post-release movement of reintroduced carnivores remains limited. We studied movements of 11 reintroduced lions (Panthera leo) in Dinokeng Game Reserve, South Africa, in their first season of release and investigated changes in movements over time. Movement patterns of lions were more diverse than expected and varied between sexes and individual groups. Some lion groups returned to the area surrounding the release site after initial exploration and avoided human settlements, suggesting that vegetation and human disturbances influenced dispersal upon release. Cumulative home range size continued to increase for all lions despite individual differences in movement patterns. We highlight the importance of considering the variation in individual-specific behaviour and movement patterns to assess early establishment and reintroduction success.
PLOS ONE | 2018
Stefan H. Foord; Lourens H. Swanepoel; Steven William Evans; Colin S. Schoeman; Barend F.N. Erasmus; M. Corrie Schoeman; Mark Keith; Alain Smith; Evans V. Mauda; Naudene Maree; Nkhumeleni Nembudani; Anna S. Dippenaar-Schoeman; Thinandavha C. Munyai; Peter J. Taylor
Human-dominated landscapes comprise the bulk of the world’s terrestrial surface and Africa is predicted to experience the largest relative increase over the next century. A multi-scale approach is required to identify processes that maintain diversity in these landscapes. Here we identify scales at which animal diversity responds by partitioning regional diversity in a rural African agro-ecosystem between one temporal and four spatial scales. Human land use practices are the main driver of diversity in all seven animal assemblages considered, with medium sized mammals and birds most affected. Even the least affected taxa, bats and non-volant small mammals (rodents), responded with increased abundance in settlements and agricultural sites respectively. Regional turnover was important to invertebrate taxa and their response to human land use was intermediate between that of the vertebrate extremes. Local scale (< 300 m) heterogeneity was the next most important level for all taxa, highlighting the importance of fine scale processes for the maintenance of biodiversity. Identifying the triggers of these changes within the context of functional landscapes would provide the context for the long-term sustainability of these rapidly changing landscapes.
Journal of Mammalogy | 2018
Robynne Kotze; Mark Keith; Christiaan W. Winterbach; Hanlie Winterbach; Jason P. Marshal
Carnivores that exhibit fission–fusion social organization can adapt group sizes to prevailing social and ecological conditions. This study focuses on social organization of African lions (Panthera leo) in the Okavango Delta, a seasonally flooded wetland. We used generalized estimating equations and generalized linear mixed models to estimate the effects of flooding, as well as prey availability and intraspecific competition on group sizes of lions. During years of high flood, total lion pride sizes as well as reproductive rates declined. Prides showed extensive overlap in annual home ranges, likely as a result of habitat saturation at high densities, and pride sizes were not limited by prey availability. At the subgroup level, the number of attending cubs was the most consistent predictor of subgroup size of adult females. For subgroups without cubs, higher numbers of neighbors in adjacent, competing prides resulted in larger subgroups in focal prides, likely to maintain numerical advantage in inter-pride encounters. Larger subgroups were also formed in response to greater availability of large prey, as successfully hunting large prey requires a greater degree of cooperation. In the southwestern Okavango Delta, competition for space resulting from changing flooding regimes is a greater limiting factor for total pride sizes than food availability.
South African Journal of Wildlife Research - 24-month delayed open access | 2002
Mark Keith; V.M. Peddemors; Marthan Nieuwoudt Bester; J.W.H. Ferguson
South African Journal of Science | 2004
J. E. Victor; Mark Keith
Journal of Experimental Marine Biology and Ecology | 2015
Ryan Rudolf Reisinger; Mark Keith; Russel D. Andrews; P. J. N. de Bruyn
Journal of Ethology | 2013
Mark Keith; Shanan Atkins; Alice E. Johnson; Leszek Karczmarski
Ecology and Evolution | 2015
Jeannine McManus; Desiré L. Dalton; Antoinette Kotze; Bool Smuts; Amy J. Dickman; Jason P. Marshal; Mark Keith