Diet-Dependent Differences in Digestive Efficiency in Two Sympatric Species of Box Turtles, Terrapene carolina and Terrapene ornata

Terrapene carolina and Terrapene ornata are sympatric in Missouri, but they tend to occupy different habitats. There is also disparity in their diets, with T. carolina tending to be more herbivorous than T. ornata. Differences in diet and habitat may require different digestive physiologies between species. We investigated the ability of these species to digest three different pure diets of fruit (blackberry, mayapple, and strawberry). Diet type had a significant effect on digestive efficiency and gut transit rate. We found T. carolina had significantly longer gut transit times than did T. ornata when fed strawberry diets but not when fed blackberry and mayapple diets. Terrapene ornata had significantly higher digestive efficiency than did T. carolina for mayapple diets but not for strawberry and blackberries diets. This study suggests that diet-dependent differences in digestive ability exist between these turtle species.