Population ecology of the softshell turtle, Trionyx muticus

Abstract

Nesting success of Trionyx muticus was studied during two field seasons from individually marked nests, Supplementary information was obtained from eggs subjected to submersion experiments in the laboratory, Open areas on high ridges of sandbars are preferred nesting sites; apparently females recognize these areas from the water. Predation on nests was low. The major cause of egg mortality was submersion produced by extended rises in water level; laboratory experiments suggest that egg viability is decreased when submersion lasts for more than one day. Nesting success was lower in 1973, an unusually wet season, than in 1974 which was unusually dry, Evidence indicates that there must be a minimum number of hatchlings in a nest to insure escape from the nest.