Population Dynamics of the Spotted Turtle, Clemmys guttata, on Carroll Island.

摘要

The population dynamics and structure of the spotted turtle, Clemmys guttata, were studies from 1970 until 1982. Carroll Island was the site of chemical testing from post WW II until 1971. Special consideration was given to the impact upon the populations of turtles by the chemicals released on Carroll Island. Several findings are noteworthy. The number of juveniles on the island has steadily declined over the 12 years of sampling. The current (1982) population is half of that estimated for 1972-73. The proportion of females dropped as low as 0.25 of the population. Four possible hypotheses are delivered to explain the observations. The most likely explanations are that a temperature anomaly or natural catastrophe dramatically reduced the proportion of females present. At the same time the population of turtles overshot the carrying capacity of the environment after cessation of an artificial or natural constraint.