OLYMPIA – Forty-three rare western pond turtles – many with tiny radio transmitters glued to their shells – were released into a pond in Mason County this week as part of an ongoing effort to prevent the species from disappearing from Washington state.
Fourteen additional turtles were returned to a state wildlife site near Steilacoom, where they were collected as hatchlings and nurtured in captivity to improve their chance of survival.
All are graduates of a recovery program for state endangered western pond turtles involving the Washington Department of Fish and Wildlife (WDFW), Woodland Park Zoo, Oregon Zoo, the U.S. Fish and Wildlife Service and others who have been working since 1990 to restore the native species.
Fifteen of the turtles released this week were bred from captive adults at the zoo. Most, however, were collected from wild sites and nurtured at the zoo until they were large enough to prevent predators such as bullfrogs and largemouth bass from swallowing them whole.
That strategy, called “headstarting,” has a simple goal, said Harriet Allen, who oversees WDFW’s Threatened and Endangered Wildlife Program.
“The key is to raise them until they are bigger than a bullfrog’s mouth,” Allen said. “At the zoo, that generally takes about 10 months. In the wild, it can take two or three years – if they make it at all.”
By keeping turtles at warmer temperatures and feeding them throughout the winter, they grow much faster, making them less susceptible to predators, Allen said.
Once common in the Puget Sound region and the Columbia Gorge, the western pond turtle declined to just 150 known animals in Washington by the time the state listed it as an endangered species in 1993, Allen said. Loss of habitat, disease and predation by non-native species such as bullfrogs decimated their numbers.
This week’s releases will bring the total number of turtles in the wild to about 1,000 at three sites in the Columbia Gorge, the wildlife site near Steilacoom and the new site on property owned by the Washington Department of Natural Resources (DNR) in Mason County.
“The western pond turtle is a species of concern under DNR’s trust land Habitat Conservation Plan,” said Commissioner of Public Lands Doug Sutherland, who leads the Department of Natural Resources. “We are so pleased to be able to provide crucial habitat that helps in a species’ recovery.”
While monitoring turtles released at the new site, WDFW and its partners in the recovery effort are already preparing for next year’s “head start” class.
In spring, biologists attached radio transmitters to the shells of 17 female turtles at the WDFW Wildlife Area near Steilacoom so they can locate their hatchlings for collection in fall. The female turtles are monitored every two hours during the nesting season to determine where they nest, said Kelly McAllister, WDFW district wildlife biologist.
Once the nests are established, they are covered with wire cages to prevent predators from eating the eggs. Once the eggs hatch, young turtles about the size of a quarter are removed from the nests and taken to the zoo, where they can grow in safety.
“The ultimate goal of the program is for enough young turtles to survive in the wild without headstarting,” Allen said. “But, for now, the risks from bullfrogs are just too great and we need the ‘headstarted’ turtles to establish new populations.’”
Allen noted that the non-native bullfrog is classified by WDFW as a “prohibited aquatic animal species,” which poses a threat to the recovery of western pond turtles and other native reptiles and amphibians in Washington.
“That designation means it’s illegal to possess or sell bullfrogs and they can be hunted without a license,” she said. “There are no bag limits, and the season is open year-round.”
The Western Pond Turtle Recovery Program is a part of Woodland Park Zoo’s Partners for Wildlife conservation initiative, an expansion of the zoo’s efforts and resources in proven wildlife conservation projects, explained Woodland Park Zoo Conservation Director Dr. Lisa Dabek. The zoo currently participates on 45 field conservation projects in more than 29 countries around the globe.