Gus has conducted research on African carnivores for over 40 years. His major studies include behavioural ecology of brown hyaenas and spotted hyaenas in the Kalahari and population ecology of wild dogs in Kruger National Park. He retired from SANParks as a Research Fellow in 2006 and returned to the Kgalagadi Transfrontier Park, South Africa/Botswana to conduct a cheetah study. The aim of the study was to define the ecological role and adaptations of the species to an arid environment, incorporating studies of feeding ecology and energetics, ranging behaviour and habitat use, mating system and reproductive success, demographics and conservation status. The results have been published in a book ‘Kalahari Cheetahs: adaptations to an arid region’. He is now an advocate for the conservation of ecosystem integrity as the pivotal conservation objective and a mentor and supporter of young African conservationists. He is writing a popular account of ‘Kalahari Cheetahs’.