Season but not sex influences burrow length and complexity in the non-sexually dimorphic solitary Cape mole-rat (Rodentia: Bathyergidae)

Little is known about how season influences burrowing activity, burrow structure or reproductive behaviour in subterranean mammals. We excavated burrow systems of male and female Georychus capensis, a solitary, subterranean rodent, in winter (wet season) and summer (dry season) to investigate whether, if any, seasonal differences were due to putative mate-seeking behaviour of males. Burrow structure differed between seasons but not between sexes. For both sexes, summer burrows were shorter and covered a smaller area, but explored the surrounding environment more efficiently than winter burrows. Summer burrows had fewer mounds, which indicated that less expansion of the burrow systems occurred during this season. We discuss these differences in exploration and the use of the environment between seasons in terms of mating strategies of G.capensis and observed levels of sexual dimorphism in our populations. This study supports recent ideas regarding sexual selection relating to exaggerated traits in females, which affect a female's ability to acquire reproductive resources that often appear similar to that selected for by males.