My main interests are lizard and snake systematics, but also biogeography of reptiles and amphibians. I was first editor and a contributor to the Atlas and Red List of the Reptiles of South Africa, Lesotho and Swaziland (2014).
There is widespread invasion of the day gecko Lygodactylus capensis within Bloemfontein (central and suburbs) and scarcity of other lizard species in the area.