Straight From the Source: How we're saving the Blanding's turtle
When we think of wildlife in dire need of conservation, cute, cuddly and charismatic species often come to mind.
Saving species such as polar bears, pandas and tigers that live in faraway, exotic places is a popular, worthy endeavor. But freshwater turtles are one of the most threatened groups of vertebrates in the world; more than half of all species face extinction. They live in the murky, overlooked depths of ponds, rivers and marshes in Illinois, and they need our help as well.
Perhaps none is more worthy of our attention than the Blanding's turtle. Found throughout the Great Lakes region, this medium-sized, semiaquatic turtle has a distinctive, bright yellow chin and throat and characteristic, if not charismatic, smile.
Blanding's turtles were once common throughout their range, including northeastern Illinois, but have experienced widespread declines due to habitat loss and fragmentation, increased predation and poaching. The survival of these turtles hinges on our ability to protect and preserve the healthy, resilient ecosystems they rely upon. In the right conditions, Blanding's turtles can live upward of 80 years. Their longevity and sensitivity to threats makes them a modern "canary in a coal mine."
In Lake County, populations of Blanding's turtles occurred at several locations, including one of the largest known populations in the state. It wasn't until the Illinois Natural History Survey completed a county status assessment in 2010 that we learned many of the populations were extremely small and declining. None were considered viable or capable of persisting without intervention.
In response, the Lake County Forest Preserve District initiated a recovery program in 2010 with the goal of ensuring long-term Blanding's turtle persistence in Lake County.
Species recovery efforts are never easy or fast. Success requires identifying the causes of the decline, addressing them, waiting, adjusting, waiting and waiting some more. We deduced that even our most significant population was in decline because adult survivorship was too low, and not enough young turtles were being produced to replace those lost adults.
Adult turtles are famously tough thanks to their hard, durable shells and ability to almost completely protect soft tissue from exposure to the elements and to predators. However, 220 million years of evolution couldn't prepare turtles for automobiles -- the greatest cause of death for an adult turtle is direct strike by a vehicle.
Blanding's turtles are more susceptible to road mortality than most, as they travel great distances to find mates, food and appropriate nesting grounds. In this urban landscape, there aren't many places where they can avoid a significant roadway.
If life wasn't hard enough for adult turtles, the youngsters have it even tougher, thanks in large part to human subsidization of predators such as raccoons. During the past several decades, raccoon populations in urban and suburban landscapes have skyrocketed. Raccoons are good at finding turtle nests and eating turtle eggs.
We found nearly 93 percent of all turtle nests were dug up and the eggs eaten, most within 24 to 48 hours.
Only about 7 percent of eggs hatch. Those lucky enough to hatch and leave the nest, have to endure 14 to 20 years of hazards before they can reproduce and contribute to the population. Overall, each egg laid has a less than 1 percent chance of ultimately becoming an adult. Those odds are not enough to sustain a healthy population.
To overcome these seemingly insurmountable odds, a two-pronged, simultaneous approach was needed.
To increase adult survivorship, LCFPD has improved habitat. Higher-quality habitat means turtles don't need to travel as far, which means less exposure to hazardous roads. LCFPD and other partners have raised public awareness. Educational materials and turtle-crossing signs were distributed to warn drivers about turtles on the road during peak times of migration.
Early signs indicate these strategies are working. When the recovery program started, adult turtles had an 88 percent chance of surviving each year. Adult survival is now estimated at nearly 94 percent.
Just as encouraging is progress made to boost the population of young turtles. LCFPD initiated a program in which we give hatchlings a head start on life by rearing them in the safety of captivity. These hatchlings come from eggs collected from adult female turtles that are incubated and hatched through a partnership with the McHenry County Conservation District's Wildlife Resource Center.
Instead of only 7 percent of eggs becoming hatchlings, more than 80 percent hatch. They're raised to a size that isn't a delicious, bite-sized morsel for a multitude of predators. In eight years, LCFPD has hatched, raised and released more than 800 turtles, and nearly 40 percent have been recaptured during follow-up monitoring after surviving at least one year in the wild.
This concurrent increase in reproduction and adult survival indicates the population of Blanding's turtles in Lake County is in far better shape than it was eight years ago. Models indicate there is now a sufficient number of young turtles to replace the older generation, which is also living longer.
Though the results thus far are promising, we are a long way from calling the species truly recovered. Long-term persistence of the Blanding's turtle in Lake County and northeastern Illinois depends on the continuation of this success. For the moment, it's encouraging for the people and wildlife of Lake County that this particular "canary" continues to do well.
This project was made possible, in part, through the support of the Preservation Foundation of the Lake County Forest Preserves. The Foundation's Adopt-a-Turtle Program has provided critical funding to support head-starting efforts. To support the Lake County Forest Preserves' Blanding's Turtle Recovery Program, consider adopting a turtle at lcfpd.org/preservation-foundation/adopt-a-turtle.