1 South African Research Chair in Conservation Physiology, South African National Biodiversity Institute, 2 Cussonia Ave, Brummeria, Pretoria 0184, South Africa.
2 iThemba LABS, 514 Empire Rd, Johannesburg 2193, South Africa.
3 UNM Biology Department, University of New Mexico, Albuquerque, NM 87131, USA.
4 Centre for Integrative Ecology, School of Life & Environmental Sciences, Deakin University, 75 Pigdons Road, Waurn Ponds VIC 3216, Australia.