Foraging and distribution patterns in a termite assemblage dominated by fungus-growing species in semi-arid northern Botswana

Abstract

Termite foraging was monitored with cellulose baits in both the wet and dry season in the semi-arid Okavango Delta region of northern Botswana. Seven wood-feeding species were found. Fungus-growing termites dominated the assemblage in all plots, and four species (Macrotermes michaelseni, Odontotermes sp. A, Allodontermes sp. and Microtermes sp.) were found in most. Foraging by smaller-bodied Allodontermes sp. and Microtermes sp. was largely confined to the wet season. Foraging by M. michaelseni and Odontotermes sp. A was more constant, but showed a general peak in the early dry season (May and June), likely due to nutrient and energy demands associated with alate production. Despite extensive overlap in distributions of these species, co-occurrences on baits were significantly less frequent than expected by chance. In addition, incidence in a plot of Allodontermes sp. and Microtermes sp. was negatively correlated in the wet season, as was that of M. michaelseni and Odontotermes sp. A in the dry season. Differences in body size, life history, and nest structure produce temporal and spatial heterogeneity in the foraging and distribution patterns of termites, and therefore suggest that consideration of community composition can improve prediction of the influence of termite assemblages on decomposition.