Morphological parameters and spring activities in a central Ontario population of midland painted turtle, Chrysemys picta marginata (Agassiz)

Abstract

Chrysemys picta marginata in a north-central sector of its range exhibits values for standard taxonomic characteristics that have wide individual variability. A population at Nogies Creek, Ontario did not exhibit values which might, from the literature, be expected ("typical") for this subspecies in that part of its range. Individual sizes do approach maxima for midland painted turtles. Nesting activities are described for the population. Photoperiod appears to be an instrumental guideline for timing daily and anriual nesting activities. Other environmental factors may temper its effect. Turtles might locate the nest sites by a simple form of homing.