Foraging by fungus-growing termites (Isoptera : Termitidae, Macrotermitinae) in the Okavango Delta, Botswana

Observations were made of foraging frequency and food selection by species of Macrotermitinae in a savanna habitat in the distal reaches of the Okavan go Delta, Botswana. A removal experiment in the field was also conducted. O bservable foraging showed seasonal peaks in frequency, related to temperatu re in Macrotermes michaelseni and to moisture in sympatric soil nesting Ter mitidae. Foraging was mostly on woody litter of the dominant canopy trees a nd mammalian dung. There was considerable overlap in the selection of food items between species but M. michaelseni were seen more frequently on items of woody litter greater than 6 mm in diameter. In Petri-dish trials,Microt ermes spp. workers were aggressive towards M. michaelseni individuals and i n the field the foraged more frequently and effectively when M michaelseni numbers were experimentally reduced. Macrotermes michaelseni appeared to av oid competition with other fungus-growing species by spatial separation wit hin the habitat and some limited separation in food selection, but intense competition is probably rare as space and food resources may rarely be limi ting.