Date of Graduation

Spring 2010

Degree

Master of Science in Biology

Department

Biology

Committee Chair

Don Moll

Keywords

alligator snapping turtle, Macrochelys temminckii, seed dispersal, chelonochory, saurochory

Subject Categories

Biology

Abstract

The alligator snapping turtle (Macrochelys temminckii) is a large freshwater turtle that inhabits many lotic water bodies in the Southeastern United States. The species consumes primarily fish but also consumes large amounts of vegetation including seeds of common persimmon (Diospyros virginiana), tupelos (Nyssa sp.), willow oak (Quercus phellos), and pecan (Carya illinoensis). Captive specimens of M. temminckii were fed samples of the above-mentioned seeds to assess how the species affects ingested seeds in order to evaluate the potential role this species may play as a seed disperser. The proportion of seeds defecated intact varied with species (57−99 %), was lowest in D. virginiana, and highest in N. aquatica. Ingestion reduced the percentage of seeds that germinated in comparison to uneaten controls in all species except Q. phellos where ingestion increased germination percent. Germination percent also decreased the longer seeds remained inside turtles. Ingestion reduced the germination rates of D. virginiana and N. aquatica seeds but increased germination rates for seeds of Q. phellos in comparison to uneaten controls. Due to fungal contamination, conclusions could not be drawn regarding the effect of ingestion on germination percent or rate of C. illinoensis seeds. This study suggests M. temminckii could potentially play some role as a disperser of Q. phellos and N. aquatica but is less likely for D. virginiana. Information regarding post-dispersal fates of seeds ingested by M. temminckii and other freshwater turtles is needed to evaluate the importance of freshwater turtles as dispersers of riparian and wetland vegetation.

Copyright

© Jean Pierre Elbers

Campus Only

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