Browsing by Author "Mokhatla, Mohlamatsane"

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    Has strategic planning made a difference to amphibian conservation research in South Africa?
    (South African National Biodiversity Institute (SANBI), 2019-09-25) Measey, John; Tarrant, Jeanne; Rebelo, Alex; Turner, Andrew; du Preez, Louis; Mokhatla, Mohlamatsane; Conradie, Werner
    Background: Conservation relies on the strategic use of resources because monies for conservation action are limited, especially in developing countries. South Africa’s Frog Atlas project established a baseline for the country’s amphibian data and threat levels in 2004, and in 2009 a prioritisation exercise developed a strategy for conservation research. Objectives: In this article, we assess this strategy for conservation research. Method: We conducted a quantitative and qualitative assessment of research undertaken since the strategy was developed. Results: The strategy has produced a lasting impact on taxonomy, ecological studies, monitoring and capacity building. Publications in all areas have increased, but particularly in conservation ecology. Other indicators are increases in the numbers of locality records for target taxa, species descriptions and postgraduate degrees with amphibians as the principal topic. We document important milestones for South African amphibian conservation, including the first Biodiversity Management Plan for Species (BMP-S) for Hyperolius pickersgilli, a smart device app that uploads locality data to an open access database, 15 years of monitoring data and new amphibian identification books for adults and children. The Red List Index calculated for South African amphibians shows that the country’s species are becoming more threatened (a 1% reduction in 10 years), but a hindcasting exercise suggests that most of the damage was already done by 1990. We provide a checklist for 131 amphibian species in South Africa, of which 82 species are endemic. Conclusion: A strategy for conservation research was found to greatly augment the focus of research on South African frogs. A new strategy should focus on fewer taxa over meaningful time spans.
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    The role of ambient temperature and body mass on body temperature, standard metabolic rate and evaporative water loss in southern African anurans of different habitat specialisation
    (PeerJ, 2019) Mokhatla, Mohlamatsane; Measey, John; Smit, Ben
    Temperature and water availability are two of the most important variables affecting all aspects of an anuran’s key physiological processes such as body temperature (Tb), evaporative water loss (EWL) and standard metabolic rate (SMR). Since anurans display pronounced sexual dimorphism, evidence suggests that these processes are further influenced by other factors such as vapour pressure deficit (VPD), sex and body mass (Mb). However, a limited number of studies have tested the generality of these results across a wide range of ecologically relevant ambient temperatures (Ta), while taking habitat use into account. Thus, the aim of this study was to investigate the role of Ta on Tb, whole-animal EWL and whole-animal SMR in three wild caught African anuran species with different ecological specialisations: the principally aquatic African clawed frog (Xenopus laevis), stream-breeding common river frog (Amietia delalandii), and the largely terrestrial raucous toad (Sclerophrys capensis). Experiments were conducted at a range of test temperatures (5–35 °C, at 5 °C increments). We found that VPD better predicted rates of EWL than Ta in two of the three species considered. Moreover, we found that Tb, whole-animal EWL and whole-animal SMR increased with increasing Ta, while Tb increased with increasing Mb in A. delalandii and S. capensis but not in X. laevis. Whole-animal SMR increased with increasing Mb in S. capensis only. We did not find any significant effect of VPD, Mb or sex on whole-animal EWL within species. Lastly, Mb did not influence Tb, whole-animal SMR and EWL in the principally aquatic X. laevis. These results suggest that Mb may not have the same effect on key physiological variables, and that the influence of Mb may also depend on the species ecological specialisation. Thus, the generality of Mb as an important factor should be taken in the context of both physiology and species habitat specialisation.