The Dietary Composition ofChrysemys Picta Picta(Eastern Painted Turtles) with Special Reference to the Seeds of Aquatic Macrophytes

Abstract

Animals facilitate macrophyte seed dispersal in various ways despite specializations of macrophytes for water dispersal. Previous diet analyses of freshwater aquatic turtles revealed that several North American turtle species consume a variety and abundance of seeds among other plant material and animal prey. We quantified the dietary habits of Chrysemys picta picta (Eastern Painted Turtle) in a Massachusetts lake to examine if these animals included hydrophyte seeds in their diet and evaluate their capacity as passive seed-dispersal agents. Fifty-four turtles were trapped and housed to collect feces. Examination of feces revealed a diverse diet with comparatively high frequencies of animal, plant, and algal matter. Eight hundred fifty-seven seeds of at least nine plant species were egested (among 87% of turtles), with all but five (99%) seeds visibly intact. Seeds of Nuphar (473) and Decodon (305) were most abundant in the feces. Life-history characteristics of both C. p. picta and Nuphar suggest an effective endozoochorous seed dispersal association.