CARROLL, Lindsay M.*; JANZEN, Fredric J.; Iowa State University; Iowa State University: Behavior and structure of a riverine population of imperiled Blanding’s Turtles, Emydoidea blandingii

Effective conservation strategies require a thorough understanding of population structure and habitat use. Incorporation of detailed information about habitat use, corridors, and age-specific and sex-specific movement of individuals into management plans better ensures proper protection of habitat critical to healthy populations. Estimating factors such as population structure, survival and density, obtained from mark-recapture data, further strengthens proper management planning and efforts. As part of a larger on-going conservation project, we provide initial data on habitat use and population structure for a population of Blanding�s turtles in a heavily human-impacted area along the Mississippi River in northern Illinois. In May and June 2005, we captured turtles with baited lobster traps or during terrestrial encounters; turtles were then weighed and measured, fitted with radio-transmitters, and released at the points of capture within 24 h. We used triangulation methods to locate all nine females each day and the four males and one juvenile every other day. Our preliminary results indicate that individuals spent the majority of time in the water occupying specific activity centers. Females in particular also used the surrounding terrestrial habitat. Mark-recapture data from 2000-2005 reveal that 45 turtles were captured 83 times; of these 45 turtles, 13 were male, 22 were female, and 10 were juveniles. These findings could elucidate geographic variation in habitat use and population structure for this imperiled species.