1. Institute of Zoology; Zoological Society of London; Regent's Park London NW1 4RY UK
2. National Museum; Florisbad Quaternary Research; PO Box 266 Bloemfontein 9301 South Africa
3. Clinic for Zoo Animals; Exotic Pets and Wildlife; Vetsuisse Faculty; University of Zurich; Winterthurerstr. 260 CH-8057 Zurich Switzerland