Stable isotope analysis of termite food habits in East African grasslands

Stable carbon isotope techniques were employed to study the food habits of the termite Macrotermes michaelseni (Isoptera: Termitidae) in a semiarid savanna habitat in Kenya. At Kajiado this species utilized approximately 70% herbaceous vegetation (mostly grass) and 30% woody vegetation, while at Ruiru approximately 64% of the vegetation utilized was woody and 36% herbaceous. Stabel carbon isotope ratios varied between castes within sites, but were consistent with the manner in which carbon flows through termite colonies. δ(13)C values increased in the sequence: diet→fungus comb→nonreproductive castes→reproductive castes. These results are in agreement with the idea that organic carbon becomes enriched in (13)C as it passes through a food chain.