Increase Text Size Decrease Text Size

Ten Year Cooperative Project Contributes to Protection of Blanding's Turtle

In 1999, a small population of Blanding’s turtles was found in Cleveland Metroparks Ohio & Erie Canal Reservation (OECR) during a park-wide turtle survey led by Dr. Hugh Quinn (former zoo Curator) and Dr. Dan Petit (former Chief of Natural Resources). In cooperation with the Ohio Department of Natural Resources, Cleveland Metroparks Zoo and Cleveland Metroparks Natural Resources Division initiated a program to increase turtle numbers at OECR as well as develop methods for potential reintroduction to other areas. In addition to surveys at OECR, the Park District’s research has centered on studying Blanding’s turtle biology at Sheldon Marsh, an Ohio DNR State Nature Preserve, and at Winous Point Marsh, a private wetland complex about 60 miles west of Cleveland. Jeanne Fromm, Jim Spetz, and Rick Spence, all former seasonal employees, spent many hours equipping turtles at both locations with radio transmitters. Radio tracking allows us to recapture turtles periodically as part of dietary, habitat use, and reproduction studies. New hatchlings at Winous Point were outfitted with transmitters to track movements and document mortality as the result of predation events.

Young hatchlings also have been reared at the Zoo as part of a “head-starting” program to provide larger individuals for reintroduction at OEC and Sheldon Marsh. Zoo Animal Keepers Brad Poynter and Nick Zarlinga provided daily care, feeding, and proper environmental conditions to encourage proper egg development and rapid growth of the young turtles.

Larger turtles (4-6 inches across) have greater survival and are less susceptible to predation. Nest and hatchling predation, mostly by raccoons, are serious threats to turtles. Through these reintroduction efforts, increased turtle numbers may help long-term survival of these populations. To date, 55 individuals have been released at OECR and 32 at Sheldon Marsh; many with transmitters to monitor their movements and survival. Numerous turtles have been recaptured, some as many as eight years after their release indicating successful establishment and survival.

Blanding’s turtles are an interesting species, and one big reason is their amazing longevity. Some individuals top 100 years and counting. What makes this longevity especially notable is that death is typically attributed to predation, automobile fatalities, or to diseases that affect individuals equally regardless of age. Long-term research in Michigan indicates that these turtles actually produce more eggs as they age, but they don’t seem to become any more vulnerable to diseases than young turtles. Compare that with the human life cycle where reproductive potential decreases with age and susceptibility to disease and other disorders increases. Basically, Blanding’s turtles are not affected by the aging process! Researchers are now trying to determine what regulates life span in turtles in hopes of figuring out how humans age.

Blanding’s turtles are found currently in 15 states and 3 provinces in Canada. In 14 of the states, the turtle is listed as endangered (4), threatened (7) or as a “Species of Special Concern” (3). Only Nebraska has a thriving population. Ohio’s historical records indicate that Blanding’s turtles were originally found in 50 locations in 13 counties. According to Carolyn Caldwell, Ohio Division of Wildlife, today’s number of surviving populations (occurrence records <10 years old) are thought to be 19 localities in 9 counties. Only three populations are known to have had successful recruitment in the past 10 years (i.e., hatchling or juvenile turtles have been observed). Moreover, two of these populations have fewer than 25 turtles, and the other may have up to 50. Such small population sizes can be negatively impacted easily. Until additional data shows the species is not in jeopardy, the threatened designation is warranted.


http://www.dnr.state.oh.us/wildlife/Home/resources/mgtplans/threatened/tabid/6006/Default.aspx (now offline)