Gaboon adders are active throughout the year, but are largely sedentary. In their prime habitat of forest–thicket–grassland mosaic in Zululand their normal foraging movements are short range, punctuated by long periods of inactivity. Occasional long distance movements suggest changes in foraging area, but these movements take place within a home range, to which the snakes show long-term fidelity. The snakes breed during the southern autumn, March to May. A male adder tracked during the breeding season performed a long, looping excursion well outside its home range. During this sally, through marginal to poor habitats and prime terrain, movements were rapid, with only short spells of inactivity, and little apparent foraging behaviour. This excursion is interpreted as mate-seeking with males actively searching for sedentary females.