1 School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Johannesburg, South Africa.
2 School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Johannesburg, South Africa; Department of Behavioural Biology, University of Münster, Münster, Germany.
3 School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Johannesburg, South Africa; Institut Pluridisciplinaire Hubert Curien, Département d'Ecologie Physiologie et Ethologie, UMR7178, 67087 Strasbourg, France. Electronic address: carsten.schradin@iphc.cnrs.fr.