Ecology of Two Endangered Aquatic Turtles in Missouri: Kinosternon flavescens and Emydoidea blandingii

Abstract

Kinosternon flavescens and Emydoidea blandingii are both included on the Missouri list of endangered species, and the Missouri populations of K. flavescens are under consideration for placement upon the federal list. There are 4 known populations of K. flavescens and 2 of E. blandingii within the state, all in Clark County in the western floodplain of the Mississippi River. Goose Pond, a small patch of remnant marsh in a former river channel of the Des Moines River, is the last natural habitat in Missouri that contains a population of either species. Sandy soil appears to be a habitat requisite for both species. K. flavescens appears to tolerate major alterations of the natural habitat, whereas E. blandingii requires clean shallow water with abundant aquatic vegetation and appears to be sensitive to habitat manipulation. K. flavescens at Goose Pond had an aquatic feeding period of only 3 mo. The species began aquatic feeding during April, but then ceased during July without any later resumption. E. blandingii fed for .apprx. 4 1/2 mo. with 2 distinct phases: the 1st phase during April, May, June, and the 1st half of July; and a 2nd phase during the latter half of Aug. and the 1st half of Sept. prior to hibernation. K. flavescens fed predominantly upon hard-shelled snails, and to a lesser extent upon insects, fish and crayfish. E. blandingii fed predominantly upon crayfish and insects. The data suggest that E. blandingii in Missouri attain sexual maturity at a carapace length of 170-180 mm.