The brown hyaena, Hyaena brunnea, lives at over twice the density of the spotted hyaena, Crocuta crocuta, in the arid southern Kalahari. This is achieved mainly through the more diverse diet of the brown hyaena, many of the components of which are small and scattered. The spotted hyaena tends to specialise on large and medium-sized mammals. Spottet hyaena territories are three times the area of those of brown hyaenas. Moreover, the social group sizes of the brown hyaena appear to be more responsive to increases in food availability than those of brown hyaenas. Both species employ a hinterland method of scent marking rather than border marking. Solitary foraging brown hyaenas also appear to use scent marking to communicate to other group members where they have recently foraged. Spotted hyaenas are the dominant species and may influence brown hyaena numbers where they occur at high densities.