Overland movement in African clawed frogs (Xenopus laevis): empirical dispersal data from within their native range

PeerJ. 2017 Nov 10:5:e4039. doi: 10.7717/peerj.4039. eCollection 2017.

Abstract

Dispersal forms are an important component of the ecology of many animals, and reach particular importance for predicting ranges of invasive species. African clawed frogs (Xenopus laevis) move overland between water bodies, but all empirical studies are from invasive populations with none from their native southern Africa. Here we report on incidents of overland movement found through a capture-recapture study carried out over a three year period in Overstrand, South Africa. The maximum distance moved was 2.4 km with most of the 91 animals, representing 5% of the population, moving ∼150 m. We found no differences in distances moved by males and females, despite the former being smaller. Fewer males moved overland, but this was no different from the sex bias found in the population. In laboratory performance trials, we found that males outperformed females, in both distance moved and time to exhaustion, when corrected for size. Overland movement occurred throughout the year, but reached peaks in spring and early summer when temporary water bodies were drying. Despite permanent impoundments being located within the study area, we found no evidence for migrations of animals between temporary and permanent water bodies. Our study provides the first dispersal kernel for X. laevis and suggests that it is similar to many non-pipid anurans with respect to dispersal.

Keywords: Aquatic; Clawed frogs; Dispersal; Locomotion; Migration; Performance; Pipidae; Stamina; Terrestrial.

Grants and funding

The National Research Foundation (NRF) of South Africa (NRF Grant No. 87759 to John Measey) provided financial support. F. André De Villiers and John Measey received financial and logistical support from the DST-NRF Centre of Excellence for Invasion Biology (CIB). This project received support from the BiodivERsA project (BiodivERsA BR/132/A1/INVAXEN) “Invasive biology of Xenopus laevis in Europe: ecology, impact and predictive models”. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.