Blanding's turtles are endangered in Illinois, and threatened nationwide, according to the zoo. Therefore, Brookfield Zoo created a breed and release program to help the wild population grow.
This fall, 12 turtles will be placed in DuPage County forest preserves.
Blanding's turtles have an approximate 2-percent chance of reaching maturity because of predators, like raccoons and herons. The turtles that live at Brookfield Zoo's Dragon Fly Marsh will be released after they've grown past their vulnerable stage.
Typically, turtles raised in captivity have an even lower survival rate than their wild counterparts. So Brookfield Zoo is taking certain precautions with the Blanding's turtles, such as having them hunt for their food, which consists of slugs and snails and small fish; and staying outside during all the seasons.
The zoo also plans to house 30 to 40 female turtles at an off-exhibit breeding space.
Blanding's turtles can live 80 to 85 years, but don't breed until they're 13 to 15 years old. That slow maturation; the fact they lay a small number of eggs- about a dozen compared the 60 or 70 other turtles lay; and an increase in predators has led to the population decline.