Foraging Ecology and Demography of Sternotherus Odoratus in a Southwestern Missouri Population
Sternotherus odoratus is a chiefly crepuscular turtle that inhabits a variety of soft-bottom aquatic ecosystems from stream and rivers to lakes, ponds, and ditches. Previous studies have examined its diet, but few have addressed other aspects of its feeding ecology. The objectives of this study were three-fold: 1) to collect demographic data on a previously undocumented population, 2) to quantify the diet of this species in the western portion of its range, and 3) to determine if there are any seasonal or sexual differences in diet. Turtles were collected from Lake Springfield, Green Co, MO from June through October 1998 (N=252). Individuals were collected, their stomachs were flushed, and fecal samples collected, and all samples were subsequently identified. This population has a male:female sex ratio of 1:1.08, a biomass of 16.28kg/ha, a density of 174 turtles/ha, and a population of approximately 1161 stinkpots. Sexual size dimorphism was noted with females having larger carapace widths and greater masses, and males having smaller platron lengths. Stinkpots consumed algae, seeds, plant material, crayfish, molluscs, insects and fish. Sexual differences existed for many of the prey categories and some of the individual taxa. Monthly dietary variation was also noted and appeared to be due to sexual differences in activity period and food availability. Stinkpots may be dispersing seeds of an aquatic plant and may obtain higher nutritive values from certain prey taxa via associative effects during digestion.
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