Saving Endangered Turtles in the Pacific Northwest

Once again, this past August the Oregon Zoo released a group of turtles that had participated in “head starting” – a chance to grow too big to be eaten by non-native predators. For 10 western pond turtles reared at the Oregon Zoo, a nearly yearlong stretch basking in the warmth and light of a simulated summer helped them grow large enough to have a fighting chance in the wild. These turtles were released in August, in addition to the 21 who were released in June. The cycle begins again, as another group of 13 hatchlings from this September are now being housed in the big turtle tubs, and are gaining weight weekly.

"Here at the zoo, the turtles experience summer year-round, so they don't go into hibernation," explains Dr. David
Shepherdson, Oregon Zoo conservation scientist. "In 11 months, they grow to about the size of a 3-year-old wild turtle and have a much greater chance of surviving to adulthood." Once the turtles reach about 70 grams (a little
more than 2 ounces), they are returned to their natural habitat and monitored for safety.  "At this size, the young turtles are able to avoid most of the predators that threaten them, such as non-native bullfrogs," Shepherdson said. In one study, scientists estimated that 95 percent of the turtles released back to sites in the Columbia Gorge survive annually.

Now listed as an endangered species in Washington and a sensitive species in Oregon, the western pond turtle was once common from Baja California to the Puget Sound. The biggest threat to fragile baby turtles has been the bullfrog. Native to areas east of the Rockies, this nonindigenous frog has thrived throughout the West, driving pond turtles and a host of other small, vulnerable aquatic species to the brink of extinction.

With the help of our GlobalGiving supporters, the Oregon Zoo is working to conserve and restore populations of this vital native animal and their numbers are on the rise. Over the past two decades, approximately 1,500 turtles have been released, and with good results: the gorge turtle population ranged from a low of 150 in 1990 to approximately 1,500 in 2011. Scientists tracking them estimate that 95 percent of the turtles released to sites in the Columbia River Gorge have survived.

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