Aardwolf: Diet and Foraging
Throughout its distribution range the aardwolf feeds primarily on one local species of nasute harvester termite (genus Trinervitermes). The preferred species are T. bettonianus in East Africa (Kruuk and Sands 1972); T. rhodesiensis in Zimbabwe and Botswana (Smithers 1971); and T. trinervoides in South Africa (Cooper and Skinner 1979, Richardson 1987a). In South Africa the diet is supplemented in winter by the pigmented harvester termite Hodotermes mossambicus (Richardson 1987a) and in East Africa during the rainy season by a number of other termites belonging mainly to the genera Odontotermes and Macrotermes (Kruuk and Sands 1972).
The aardwolf is a solitary forager. Even within mated pairs, individuals forage away from one another. The unweaned young are the only individuals that will be tolerated to accompany an adult when foraging (Koehler and Richardson, 1990). Its termite prey occur in dense concentrations, completely exposed on the soil surface while browsing or collecting dry grass (Kruuk and Sands 1972, Richardson 1987a). Unlike most other ant- or termite-eating mammals, such as the aardvark (Orycteropus afer), which have to dig to access their prey, the aardwolf licks termites from the soil surface using its broad, sticky tongue. A single aardwolf can consume up to 300,000 termites in one night (Koehler and Richardson, 1990; Richardson and Bearder, 1984; Richardson, 1987a).
The aardwolf is primarily nocturnal, and its activity periods seem to be determined largely by the activity of termites. The termite species, Trinervitermes trinervoides, cannot tolerate direct sunlight (Hewitt et al. 1972) so it is primarily active at night. However, during cold nights in winter these termites are inactive, so the aardwolf becomes active earlier in the afternoon in order to feed on the heavily pigmented termite Hodotermes mossambicus, a diurnal species (Hewitt et al. 1972, Richardson 1987a). The aardwolf nevertheless experiences a period of food deprivation during the southern African winter and loses up to 20% of its body weight (Richardson 1987a, Anderson 1994). This is a critical period for the cubs and many die during particularly dry years (Richardson 1987a). Although there is no winter in East Africa, T. bettonianus appears to be less active during the wet season, so the aardwolf has to feed on a wider variety of termites (Kruuk and Sands 1972). It is unknown whether this is also a period of food deprivation for the aardwolf in this region.