Saving the Blanding's Turtle from Extinction

For 21 years, Forest Preserve District of DuPage County has worked to provide a safe place for Blanding’s turtle eggs to hatch in an effort to boost the population of this state-endangered animal as part of its Project Head Start.

To date, more than 3,000 Blanding’s turtles have been hatched by the District. In 2016 seven of the tracked females that produced eggs were Project Head Start hatchlings themselves more than 13 years ago. That’s particularly noteworthy because on average, it takes at least 14 years for female Blanding’s turtles to start breeding. So the eggs from those seven turtles were the program’s third generation or “grandchildren.”

Since 1996, the program has reared and released nearly 2,100 young turtles. In recent years, at least 90 percent of the fertile eggs recovered resulted in hatchlings. In 2013, 204 fertile eggs were collected and hatched, creating an unprecedented 100 percent hatch rate.

The program was started after District staff noticed they were only finding adult Blanding’s turtles in the preserves and no juveniles or young adults, indicating that Blanding’s turtles were dying off faster than they could repopulate, said District ecologist Dan Thompson.

One of the biggest threats to Blanding’s turtles is predators eating their eggs in the nest. During their 60-day incubation period, 90 percent of turtle nests are destroyed by predators each year. Raccoons are the most voracious predators of Blanding’s turtle eggs and hatchlings, juveniles and occasionally adult turtles. Other predators include the skunk, opossum and mink. Rising populations of these predators in many areas of the turtle’s historic range contributes to the loss of this species and is why so few turtles hatch or reach adulthood.

Blanding’s turtles (Emydoidea blandingii) live in wetlands and marshy areas in the Midwest and Northeast but is threatened by predators, habitat loss and heavy traffic. The medium-sized turtle can live more than 80 years, but it takes 14 to 20 years to reach maturity. The turtles will produce a clutch of 12 ‒ 13 eggs only once a year.

To improve their odds, every spring Thompson and his cohorts don hip waders and take to the wetlands and marshes to collect pregnant females before they lay their eggs. They bring the pregnant (gravid) turtles to the District’s Willowbrook Wildlife Center in Glen Ellyn, which is equipped with nurseries to receive and incubate the eggs. Each female is numbered and identified as are the eggs she lays, providing a scientific record of each mother and clutch of baby turtles to establish a database of genetic information and DNA. When the female is done laying eggs and ready to be released back into her natural habitat, she is fitted with a radio transmitter on her upper shell, or “carapace,” to make it easier to locate her next year.

After the eggs hatch, they are numbered and given a medical checkup to determine their weight, length and general health. They are kept and reared for about a year before being released back into the preserves after they are fitted with a microchip to help identify them in the future.

During the program’s 21 years, the District has expanded the program to include Wheaton Park District’s Cosley Zoo, Peggy Notebaert Nature Museum, Brookfield Zoo, St. Charles Park District, and the John G. Shedd Aquarium. Research has also been conducted with many local institutions such as the Benedictine University, University of Illinois, Loyola University, Wheaton College, Western Illinois University, Northern Illinois University and Governors State University.

The partnerships have allowed the District to expand and improve the program. To recover a species from the brink of extinction is a very difficult and challenging task. A collaborative effort such as this will have a much greater chance of success than one agency on its own.

Links to other information about the District’s Blanding’s Turtle program:
YouTube video on Brookfield Zoo pond
Helping the Blanding's Turtle One Egg at a Time 
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