Effect of Ingestion by Alligator Snapping Turtles (Macrochelys Temminckii) on Seeds of Riparian Vegetation
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.
alligator snapping turtle, Macrochelys temminckii, seed dispersal, chelonochory, saurochory, Biology
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