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Predation of Radio-Marked Mallard (Anas platyrhynchos) Ducklings by Eastern Snapping Turtles (Chelydra serpentina serpentina) and Western Fox Snakes (Pantherophis vulpinus) on the Upper Mississippi River

Kenow, K.P., Kapfer J.M., and Korschgen C.E., 2009, Predation of Radio-Marked Mallard (Anas platyrhynchos) Ducklings by Eastern Snapping Turtles (Chelydra serpentina serpentina) and Western Fox Snakes (Pantherophis vulpinus) on the Upper Mississippi River: Journal of Herpetology, v. 43, n. 1, p. 154–158.

Abstract

Information on the predation rate of Eastern Snapping Turtles (Chelydra serpentina serpentina) and Western Fox Snakes (Pantherophis vulpinus) on waterfowl, particularly ducklings, is minimal. Most information that exists focuses on the percent of waterfowl found in the diet of sampled turtles or snakes. Although this information is useful, it does not elucidate the potential effect of reptile predation on waterfowl populations by measuring predation rate (i.e., the number of sampled ducklings consumed by reptile predators). We attempted to determine this by tracking the fate of 448 day-old Mallard (Anas platyrhychos) ducklings from 1991–1994 on the Upper Mississippi River. A total of 120 ducklings were preyed upon during the study (26.7% predation rate). Of these, 13 were consumed by Eastern Snapping Turtles (2.9% predation rate) and four by Western Fox Snakes (0.8% predation rate). Predation rate by reptiles was lower than mammals and similar to that of fish and birds, but several depredations with undetermined sources could have been caused by Eastern Snapping Turtles. For a proper perspective on predation impacts on duckling populations, one must also consider the influence of habitat quality as it relates to the interactions of predation, food resources, and cover.

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