Portlanders may feel like summer’s just reaching its peak. But for six western pond turtles reared at the Oregon Zoo, a nearly yearlong stretch of warm days and nights has drawn to an end.
The turtles have spent the past 11 months at the zoo basking in the warmth and light of a simulated summer, and growing large enough to have a fighting chance in the wild. The zoo returned these endangered reptiles to the wild July 29, with the help of its conservation partners and some teens from local youth programs. On June 30, the zoo released 11 of the largest turtles it had been rearing over the winter, and this batch of six will be the last ones for the year.
The 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, Bonneville Power Administration and USDA Forest Service. 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. In one study, scientists estimated that 95 percent of the turtles released back to sites in the Columbia Gorge survive annually.
Local students from Portland Community College’s Biology and Management of Zoo Animalsprogram and the Oregon Zoo’s Zoo Animal Presenters program helped biologists release the turtles in the Columbia River Gorge. “We like to involve local students and youth programs in these releases whenever possible,” Shepherdson said. “When you actually see a zoo-reared turtle released back into the wilds of the Columbia Gorge, it makes a much bigger impact than if you’re just learning about conservation efforts.”
Two decades ago, western pond turtles were on the verge of completely dying out in Washington, with fewer than 100 turtles left in the state. Today, researchers estimate there are more than 1,600. 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.
To watch a video about the zoo’s western pond turtle recovery efforts, visit:
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With the help of our GlobalGiving supporters, the Oregon Zoo is working to conserve and restore populations of the Western Pond Turtle and we have been making great progress.
The population in the Conservation Lab is now 24 hatchlings. The Washington Department of Fish and Wildlife (WDFW) brought us seven hatchlings this spring from the Washington side of the Columbia river gorge. They weighed 5.3-10.5 grams at the time and would be susceptible to non-native predators at this size. These turtles hatched in Sept of 2013 and wintered in the mud on the bottom of the ponds in the gorge. They were collected by WDFW Biologists as they started to come out of the mud in the spring and they already 7.6-23.6 grams. Now they are safe from introduced species such as bass and bullfrogs that might decide they make a nice snack. By the time they leave us they will be too big to be consumed by these predators.
By contrast the 13 hatchlings zoo staff fondly call 'the Smalls' are now 90-146 grams! They would have hatched at the same time as the new ones but have lived in the Oregon Zoo Conservation Lab where the sun always shines and food is plentiful, a great example of the difference the zoo’s ‘head starting’ program makes.
We also still have four hatchling holdovers from last year (167-206.5 grams) affectionately referred to as 'the Bigs', who hatched in Sept of 2012. Like our newest additions, they also spent their first winter in the muddy ponds of the gorge. They were not large enough for release last summer but will be released this year. The most recent additions will stay at the zoo for another year.We hope to release most of 'the Smalls' and all of 'the Bigs' this summer bringing our total for release this summer to around 17!
Thank you for your support of this vital program.
They survived the dinosaurs, but turtles worldwide are facing a modern extinction crisis, with half of all species at risk of disappearing.
Once common from Baja California to Puget Sound, the small, long-lived western pond turtle (Actinemys marmorata) is listed as endangered in Washington and threatened in Oregon. The Oregon Zoo works with Washington Department of Fish and Wildlife (WDFW) to help restore this shy reptile to its historic range through a unique head-starting program. As a result, Western pond turtle numbers are on the rise.
With the help of Global Giving supporters, another group of Western Pond Turtles is getting their “head-start” at the Oregon Zoo this winter. 13 new turtles, along with 4 hold overs from last year, are currently basking in the warmth and light of a simulated summer. In the wild, hatchlings become dormant in the cold. But the enhanced light and warmth at the zoo stimulates them to continue to eat and grow.
And they are all growing quickly. The four hold overs who were hatched in September 2012 now weigh between 106-145 grams and the new hatchlings are 30-75 grams. They will likely be released in July or August of 2014. By this time, they will be large enough to have a fighting chance in the wild.
The turtles are raised in the conservation lab within the Pacific Northwest Exhibit of the Oregon Zoo, so visitors and zoo campers are able to observe their growth and learn more about this important conservation project.
On behalf of the turtles, zoo conservationists and our young learners, thank you!
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. DavidShepherdson, 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 littlemore 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.
It’s Turtle Season!!! ... Turtle comings and goings from Oregon Zoo's Conservation Lab
The group of young western pond turtles that Washington Department of Fish and Wildlife field biologists delivered to us in May of 2012 really got big fast and were recently returned to spend the rest of their lives in the wild.
GlobalGiving donors might remember that instead of collecting these baby turtles right after hatching in September 2011, biologists allowed these hatchlings to spend their first winter as they naturally would - hiding in the mud and dirt in and around the ponds in the Columbia River Gorge. When these young turtles began to emerge from their hiding places in early May of 2012, biologists collected them so they wouldn’t be eaten by invasive predators. When collected, these 17 little guys were still about the same size as they were when they had hatched (~5-10 grams) since they had not been eating during their winter hibernation.
Biologists brought these hatchlings to the safety of the Oregon Zoo Conservation Lab last May for “head starting” – a chance to grow too big to be eaten by non-native bullfrogs and bass. Within four months, these 17 were over 100 grams! They were joined by 21 freshly-hatched turtles in September that brought our winter count to 38. The size difference between the May and September arrivals was obvious at first but now some of last fall’s hatchlings have grown larger than their older cousins in our Lab.
This May, those hatchlings were joined by four more collected in the Gorge. Once again, these were animals that had wintered out in the wild. As of this report, they are still VERY small turtles! If you come by the Lab during the month of August, you can see these little guys in the Conservation Lab window. These four will be with us until next spring.
On June 21st, field biologists released a group of our largest 27 youngsters into the same ponds in Washington where they were collected last May. All reports are that they are thriving in the wild! We plan to release another batch of turtles next month. Before we do, however, they will be given some identifying marks on their carapaces (shells) as well as transponder chips implanted by our veterinary staff. These provide us with a means of permanently identifying head-started turtles so that we can track their progress in the wild.
By September, we will have a new batch of freshly-hatched western pond turtle babies in our warm Conservation Lab in the Cascades building basking under the sun lamps, swimming in heated pools and enjoying a great variety of food items.
With your help, our turtle project continues to support the recovery of this imperiled species here in the Pacific Northwest and is a great example of how the Oregon Zoo is fulfilling our mission to inspire our community to create a better future for wildlife. Since 1991, more than 1,500 western pond turtles have been raised and released by zoos in Portland and Seattle and the turtle population in the Columbia River Gorge has increased from 150 to 1,500.
If you come by the Oregon Zoo Conservation Lab to check on their progress, please be sure to introduce yourself as a GlobalGiving fan of turtles!
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