Termitivore or detritivore? A quantitative investigation into the diet of the East African caecilian Boulengerula taitanus (Amphibia: Gymnophiona: Caeciliidae)

Abstract

AbstractMost caecilians are thought to be generalist predators of soil ecosystem engineers (earthworms, termites and ants), but it has been suggested that members of the East African genus Boulengerula are specialist predators. Surprisingly, in the only detailed study of diet of any Boulengerula, the authors speculated that B. taitanus is partly detritivorous, based on the large amount of organic matter found in the alimentary canal. Here we test the conflicting hypotheses that B.taitanus is a termitivore or detritivore, using the stomach and gut contents of 47 specimens collected in the Taita Hills, Kenya. Termites and earthworms contribute most significantly to diet by number and mass, respectively. These constitute the major dietary items, together with dipteran larvae and other soil macrofauna. Contents of the intestine are mostly soil and organic matter originating from prey items. The mass content of the intestines averages 69% of total gut contents, and is significantly greater than identifiable stomach contents. The null hypotheses that B. taitanus is a generalist and a predator are not rejected.