Abstract:

Using predictive modelling to guide the conservation of a Critically Endangered KwaZulu-Natal endemic

Jeanne Tarrant 1, Adrian J Armstrong 2

1African Amphibian Conservation Research Group, School of Environmental Sciences and Development, Potchefstroom Campus, North-West University, Private Bag X6001, Potchefstroom, 2520, South Africa.
2Conservation Planning Division, Ezemvelo KZN Wildlife, P.O. Box 13035, Cascades, 3202, South Africa

Knowledge of distribution is crucial for implementing appropriate conservation measures. Amphibians are the most Threatened Class of vertebrate, with wetland-associated anurans in particular suffering high levels of habitat loss. We used predictive modelling to better understand the distribution of the Critically Endangered Pickersgill’s Reed Frog (Hyperolius pickersgilli) and to guide conservation action. MaxEnt distribution models were produced based on limited occurrence data. Predicted localities with probability of occurrence ? 60 % were surveyed. During the survey period (2010 – 2012), only six new subpopulations were discovered. The mean probability of occurrence for the species at wetlands where it was detected was greater than that at wetlands where it was absent. In addition, 17 known historical localities were re-visited and the species was deemed absent at 8 of these. The total number of localities at which the species is now known to occur is 17. We recalculated the area of occupancy and extent of occurrence for the species as 108 km² and 2081.5 km², respectively. According to the IUCN Red List criteria, the status of H. pickersgilli is thus Endangered based on results of this study. A friction map was used to assess linkages between potential meta-populations as derived from the modelled distribution. These maps will be used to identify habitat for rehabilitation and to guide translocations and re-introductions. Given the degree of isolation of subpopulations and the potentially severe threats to most of these, urgent conservation action for H. pickersgilli is crucial. This study provides a method for use in conservation planning for wetland-breeding amphibians.

Presentation Topic

Using predictive modelling to guide the conservation of a Critically Endangered KwaZulu-Natal endemic

 

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Potchefstroom Campus, North-West University, Private Bag X6001, Potchefstroom, 2520, South Africa

 

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