About the Authors

W. Louis Phipps

Affiliations Department of Paraclinical Sciences, University of Pretoria, Onderstepoort, Guateng, South Africa, School of Biological and Biomedical Sciences, Durham University, Durham, Co. Durham,United Kingdom

Stephen G. Willis

s.g.willis@durham.ac.uk

Affiliation School of Biological and Biomedical Sciences, Durham University, Durham, Co. Durham,United Kingdom

Kerri Wolter

Affiliation Vulture Programme, Plot 121 Rietfontein, Brits District, North West Province, South Africa

Vinny Naidoo

Affiliation Biomedical Research Centre, University of Pretoria, Onderstepoort, Guateng, South Africa

Competing Interests

The authors confirm that Stephen Willis is a PLOS ONE Editorial Board member. This does not alter the authors' adherence to all the PLOS ONE policies on sharing data and materials.

Author Contributions

Acted as the first author's study supervisor: VN SGW. Conceived and designed the experiments: WLP SGW KW VN. Performed the experiments: WLP KW. Analyzed the data: WLP SGW. Wrote the paper: WLP SGW VN.