Movement Patterns, Activity, and Home Range of the Eastern Spiny Softshell Turtle (Apalone spinifera) in Northern Lake Champlain, Quebec, Vermont

We studied movement patterns, activity, and home range of the eastern spiny softshell turtle (Apalone spinifera) in northern Lake Champlain (Quebec, Canada; Vermont) from 1996 to 1999. This turtle population is at the northern limit of its range and considered threatened. Of the 30 individuals captured and marked, 15 females and eight males were equipped with radio-transmitters and monitored from two weeks to 29 months. Mean annual home range size for females (32.06 km2, N = 11) was significantly larger than for males (2.75 km2, N = 4). Home ranges generally consisted of a spring-summer concentration area (0.90 km2) and a fall-winter concentration area (1.80 km2), plus the area traversed between these concentration areas. In general, movements did not vary significantly from May to September, but turtles were less active after mid-September. Three hibernacula and three nesting sites were identified. Seventy five percent of the radio-tracked individuals were concentrated in a small area surrounding one hibernaculum from September to April. We hypothesize that habitat fragmentation, both natural and resulting from human activities, was in part responsible for the large home range and long movements observed. Results indicate that, to conserve this spiny softshell turtle population, the seasonal concentration areas need strict protection, although a lakewide approach promoting the preservation of natural habitats is also necessary.