Habitat Use, Movements, and Nesting of Emydoidea blandingi in Central Wisconsin

Abstract

Eight radio-tagged Blanding's turtles (Emydoidea blandingi), monitored from June 1983 to January 1984, used ponds more often than predicted on the basis of available habitat while marsh habitats were used less than their availability. Most wetlands used by the turtles had water 0.5 m. The activity centers of two males (0.57 ha and 0.94 ha) did not differ significantly in size from those of six females (x = 0.56 ha, SD = 0.293). Male and female activity centers overlapped (x = 12%, SD = 14.7), and female activity centers overlapped with those of other females (i = 26%, SD = 16.5). Two males did not share activity centers, although other males were captured within them. Distances between activity centers of two males (260 m and 635 m) were not significantly different from those among centers of six females (x = 489 m, SD = 338 m). Females moved significantly greater distances per day (N = 56, 1 = 95.1 m, SD = 79.0) than did males (N = 21, x = 48.4 m, SD = 41.2). Mean nest distances from water, and nonnesting activity centers, were 168 m (SD = 90.8 m) and 620 m (SD = 144.0 m), respectively. At least four nests were destroyed by predators within 24 h of completion, and all nests were eventually destroyed. Fourteen of 16 nests were in grasslands. Life history data and the habitat requirements for Blanding's turtle (Emydoidea blandingi) are poorly known (McCoy, 1973; Graham and Doyle, 1977; Congdon et al., 1983). Yet, wetland alteration or elimination by humans is believed to be an important factor in the decline of many E. blandingi populations (Smith, 1961; Minton, 1971; Christiansen, 1981). We here provide quantitative data on the nesting ecology, movements, and habitat use of this species to provide baseline information enabling development of conservation strategies. MATERIALS AND METHODS Data were collected from June 1982 to January 1984 on the Petenwell Wildlife Area (PWA), a 291 ha protected wildlife area in Adams County, Wisconsin (TI8N, R4E, Sections 1 and 4), that is managed by the Wisconsin River Power Company. The PWA is located on the southern edge of an ecologic tension zone (Curtis, 1959), an area of transition (ca. 15-50 km wide) between northern and southern vegetation in Wisconsin. The study area is a complex of wetlands, including speckled alder (Alnus rugosa) swamps, marshes, small ( 4.5 m in height (tree) were determined with a measuring tape. A 0.5 m squ re frame was centered on the nest site to visually estimate coverage and frequency of occurrence of vegetation (Daubenmire, 1959). All statistical tests are Students t-test unless stat-