During June 2022, Frances Fischer, Friends land trust coordinator, and Sara Woods, Friends stewardship manager, began most mornings outfitted in chest waders, not their typical field attire. But they needed to stay warm and dry while working on a special project: the first population study in more than ten years of the endangered western pond turtles inhabiting Friends of the Columbia Gorge Land Trust's Turtle Haven Preserve.
Located in the Columbia Gorge near Stevenson, Washington, the 64-acre turtle sanctuary, closed to the public, is replete with creeks, wetlands, ponds, and perches, such as half-submerged logs, ideal for basking in the sunshine. In 2015, through its Preserve the Wonder campaign, Friends purchased the property from private ownership to protect the pond turtles and their habitat.
The current research, facilitated by a team of biologists with the Washington Department of Fish and Wildlife (WDFW), sought to both assess the health of the turtles and find out whether their population had increased, particularly after periodically releasing juvenile “headstarted” turtles reared at the Oregon Zoo throughout the last decade.
The process
“Counting turtles in the wild takes time and tenacity, but it’s also rewarding and fun,” says Woods. “I felt lucky to be able to hold them, recognizing how close they came to extinction just 30 years ago.”
Fischer agrees, and adds, “They are really sweet and docile, and have lots of personality. And unlike the painted turtles in the ponds, they don’t bite you.”
For 21 consecutive days, the research team paddled, via flat-bottomed boats, across seven shallow ponds where they strategically placed 40 floating hoop nets baited with smelly sardines. Each morning, they returned to the traps with buckets to collect any turtles and, as necessary, refresh the fish.
“We use a methodology called mark-recapture,” says project lead Stefanie Bergh, a wildlife biologist with WDFW. “Basically, you’re marking your animal and then capturing it again over time.”
Some turtles already have tiny microchips or PIT tags from past studies, which researchers scan, Bergh explains. For a turtle that has never been caught, they assign it a number, weigh, measure and photograph it, and conduct a health assessment.
Next, the team marks its shell with nail polish, which wears off, to show the turtle has been counted, and then releases it back into the pond. After repeating this protocol for three weeks, Bergh says they can be confident they have captured most of the turtles. Finally, they analyze the data.
Results
In September, WDFW reported an estimate of 157 individual turtles out of 385 captures at Turtle Haven. In 2011, they estimated only 96 individuals; however, at that point, they did not have access to the entire property, so the results are not directly comparable, Bergh notes. Still, the findings are encouraging, she says.
Additional good news: the team caught nine new wild recruits. “These are young turtles that we have not previously marked. They were born in the wild and survived the hatchling stage of life. This means that the bullfrog removal efforts that we have been doing are working,” Bergh explains.
American bullfrogs, non-native species, are the main predators of juvenile turtles, Bergh adds. “If all the little guys are being eaten by bullfrogs, we’re not going to make any headway growing our populations.”
As for the turtles’ health, the study revealed that 35% of them had shell disease, 22% were suspected of having the disease, and 43% did not have it. “Shell disease is a novel disease that we are currently studying with assistance from scientists across the country,” Bergh says. “We’re investigating methods to treat it, and we’re not sure how it affects the turtles’ survival. We’re trying to figure all that out now.”
Next Steps
This fall, Friends staff and volunteers have been improving the habitat at Turtle Haven, making a big push to remove invasive plants, such as thick, thorny blackberry bushes, which impede the turtles’ movements from pond to pond. They are also planting native bunchgrasses that grow in round tufts, leaving paths for the turtles to travel and reach nesting habitat, explains Fischer.
In the next few years, Friends hopes to transfer Turtle Haven to the U.S. Forest Service, which owns hundreds of acres of surrounding lands. But Friends will continue, for as long as necessary, to steward the preserve for the turtles as they forge ahead, at their own slow pace, and against the odds, on their steady, determined course of recovery.
Cate Hotchkiss is a freelance writer and photographer who lives in Hood River with her husband, two children, and labradoodle. View Cate's photography website.
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Turtle Haven Land Trust Preserve
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