Note: The Oregon Zoo provided KATU.com with this report.
PORTLAND, Ore. -- The Oregon Zoo released nearly 60 endangered western pond turtles back to the wild on Monday. The release was overseen by children involved in the Gorge Explorers' Summer Stewards program.
These endanged Washington turtles have spent the past 11 months under lights, simulating perpetual summer, inside the Oregon Zoo. "The lights trick the turtles into thinking it's still summer so they don't go into hibernation," said David Shepherdson, the zoo's conservation program scientist. "The turtles grow and grow, experiencing three years' growth in 11 months."
Once the turtles reach a suitable size of about 70 grams (a little more than 2 ounces), they are returned to their homes and monitored for safety.
"Since the turtles are larger, predators such as non-native bullfrogs and large-mouth bass are no longer threats," Shepherdson said.
Turtle reintroduction is part of a collaborative effort by the Oregon Zoo, Woodland Park Zoo, Washington Department of Fish and Wildlife, U.S. Fish and Wildlife Service and Bonneville Power Administration. As part of the Western Pond Turtle Recovery Project, conservation scientists "head start" newly hatched turtles gathered from wild sites, nurturing them at both zoos for about 11 months.
"Spending the first months of their life at the zoo gives the turtles a real edge," said Shepherdson. "The Woodland Park Zoo and the Washington Department of Fish and Wildlife have been working to save Washington's western pond turtles for 19 years. We're glad we could provide additional assistance in helping save these highly endangered turtles."
Thirty local children enrolled in the Gorge Explorers' Summer Stewards program, at least half of them ESL students, will help biologists release the turtles in the Columbia River Gorge.
"It is one thing to learn about conservation efforts, but it makes a much bigger impact when you actually see a zoo-reared turtle released back into the wilds of the Columbia Gorge," Shepherdson said.
The Gorge Explorers' Summer Stewards program provides students entering fourth grade in the fall with an opportunity to learn environmental stewardship, science literacy, improved language and social skills, confidence building, and working as a team, at no cost to the kids' families. It also provides six high school students with the opportunity for employment for the summer in a program designed to allow them to build job skills, work on a résumé, explore informal education career ideas through the development of mentoring skills with the younger children, and to provide environmental stewardship service projects in the community. The program is a collaboration between the Columbia Gorge Discovery Center, the Columbia Gorge Ecology Institute, USFWS and the Northern Wasco County School District 21.
"Going out to the release site helps us reach our aim, which is to provide the kids with a meaningful summer learning experience tied to their natural environment," said Jenny Gilbert, conservation education coordinator with the program. "It also provides the high school students an opportunity to practice their leadership skills and learn more about environmental stewardship."
Teens from the Oregon Zoo's Zoo Animal Presenters program, the Youth Conservation Corp and the Skamania Youth Forest Success program also will take part in the release.
Just a decade ago, western pond turtles were on the verge of completely dying out in Washington, with only 150 turtles left in the wild. Today, researchers estimate there are about 1,400.
Habitat degradation and disease were, and still are, problems, but the biggest threat to fragile baby turtles is 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.
Another non-native threat to western pond turtle survival is the red-eared slider. Sliders are native to the same range as the bullfrog and are winning the survival race against the native turtles. The sliders lay eggs later in the season and dig up existing turtle nests to use as their own.
To help restore these rare pond turtles to their natural habitat, recovery workers take to the field each year. Under the supervision of western pond turtle expert Kate Slavens, they count, trap and fit transmitters on adult female western pond turtles. The female turtles are monitored every two hours during the nesting season to determine where they nest. The nests, which the females dig in the ground and then cover after depositing their eggs, are protected with wire "exclosure" cages that help prevent predators from eating the eggs. The eggs are then allowed to incubate naturally, and the hatchlings are collected in the fall.
Hatchlings are about the size of a quarter when they are removed and taken to the zoo facilities, where they can grow in safety. Unlike wild turtles, zoo turtles are fed throughout the winter, so by their summer release, the 11-month-olds are about as big as 3-year-old turtles that grew up in the wild.
Some of the juvenile turtles are equipped with radio transmitters before release, so biologists can learn more about post-release dispersal, habitat use during active and hibernation periods, and, ultimately, their survival rate. Scientists tracking the released turtles estimate that 95 percent of the turtles released back into the Columbia River Gorge have survived.
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 Puget Sound. The Oregon Zoo's participation in the Western Pond Turtle Recovery Project is funded through The Oregon Zoo Foundation's Future for Wildlife conservation fund.
The Oregon Zoo is also helping turtles in Oregon. Working with Oregon Department of Fish and Wildlife, the zoo helped establish the Oregon Native Turtle Conservation Group, which helps field biologists monitor and track populations of western pond and western painted turtles in and around the Willamette River. The group created a Web site to educate the public about the plight of the native Oregon turtles, www.oregonturtles.com. The site includes an electronic form that allows the public to report turtle sightings to ODFW and the Oregon Zoo, which aids both agencies in the tracking process.
The western pond turtle captive-rearing effort is a project of the NW Zoo & Aquarium Alliance, which promotes collaboration on regional conservation among zoos and aquariums in the Pacific Northwest.