The rocks that swim – western pond turtles

three turtles on a log.

Three western pond turtles bask on a log in an Oregon wetland. Western pond turtles are this region’s only native freshwater turtle and without conservation efforts their populations will continue to decline. Credit: Simon Wray/Oregon Department of Fish and Wildlife


By Michelle Hunt and Susan Sawyer
April 15, 2021

a hand holding a small turtle.

The Yreka Fish and Wildlife Office is developing a turtle research project along the Klamath River that will determine the habitats needed for their survival and if they are being impacted by non-native species such as the red-eared slider. Credit: John Heil/USFWS

What looks and feels like a river rock, has four webbed feet, a pointy snout with beady eyes, buries itself during winter, and dines on small frogs, fish, aquatic insects and plants?

These are attributes of the two species of western pond turtle, the northwestern and the southwestern, found in ponds and streams from Baja California north through California, Oregon, and Washington and into a portion of Nevada.

They are unique and charismatic hard-shelled reptiles and this region’s only native freshwater turtle. As opportunistic omnivores that eat a wide variety of prey, they are an important part of the ecosystem. Recently however, western pond turtle numbers have been declining, and in response the U.S. Fish and Wildlife Service considers them to be an “at-risk” species. Without critical conservation efforts their numbers are likely to continue to decrease.

So, what does “at risk” mean and how did they get to this point?

Western pond turtles have faced many threats to their survival ever since the fur trade and mining camps flourished on the West Coast. From the late 1800s to the early 1900s, an estimated 18,000 pond turtles were consumed per year, as the featured ingredient in turtle soup, a delicacy served in high-end San Francisco restaurants.

a turtle on land

Although turtles are considered primarily aquatic, they spend much of the year on land hibernating in cold and hot weather, nesting or traveling between bodies of water. Credit: Washington Department of Fish and Wildlife

As the decades passed, turtle habitat was altered as urban development and road traffic increased. Also, introduced non-native species such as bullfrogs and largemouth bass prey on turtle hatchlings.

Another concern is that pets, such as the red-eared slider, are released into the wild and compete with western pond turtles for food and space. As if all of that wasn’t enough, a mysterious disease that causes shell deterioration is now impacting some pond turtle populations in Washington state.

In response to these threats, a petition was introduced calling for federal protection of western pond turtles under the Endangered Species Act, an action which officially put the turtles in the “at-risk” category. The Service is now reviewing the petition and looking at the causes of negative impacts on turtle numbers.

To help conserve these unique reptiles, collaborative partnerships and research projects with states, landowners and other federal agencies are being identified and prioritized to determine the next steps in giving these turtles a chance to rebound.

two turtles on a log.

An adult red-eared slider, left, is a species of turtle native to the southeastern United States and commonly sold in the pet trade. When released in the wild, they are known to compete with the smaller western pond turtles, right, for food and habitat. Credit: John Bailey/California Herpetological Association

In the Yreka Fish and Wildlife Office, Anne Loggins, wildlife biologist, is developing a summer study project with student interns in the Service’s Directorate Fellows Program. The research will assess the four distinct habitats turtles need for survival: aquatic with bank vegetation, basking, nesting, and overwintering sites.

a woman measuring a pond turtle.

Lara Enders, wildlife biologist in the Reno Fish and Wildlife Office measures a western pond turtle during field work on the Carson River. The Service and the state of Nevada are collaborating on pond turtle research to learn more about their life history. Credit: Mark Enders/Nevada Department of Wildlife

“Our goal is to survey sites along and near the Klamath River to observe and count turtles and identify different size classes, which can tell us if the population is reproducing,” said Loggins. “We'll also determine where red-eared sliders, a non-native species, are competing with western pond turtles.”

In Nevada, western pond turtles are limited to isolated populations within three watersheds. Due to the pond turtles’ rarity here, they are considered a “species of conservation priority” by the state Department of Wildlife. The Service’s Reno Fish and Wildlife Office is supporting current research by the state that includes tracking long-range turtle movement and investigating genetic relationships between pond turtle populations.

“The state of Nevada is making management decisions to help these turtles thrive in our rivers for generations to come,” said Mark Enders, a state wildlife biologist based in Reno. “Western pond turtles are living relics that date back over two million years ago, yet we still find them in our rivers today. If we can have a positive influence on their conservation and ensure their continued survival, that would be the best possible outcome of our work.”

Adult turtles, which are about as long as a dinner fork and weigh up to two pounds, are capable of amicably sharing space, but can also be log, stream bank, or rock “hogs.” They have been observed having physical altercations and gesturing - the ultimate bobble head display - to settle disputes over preferred basking spots. Although expert swimmers, western pond turtles can spend much of the year on land, hibernating during cold and hot weather (aestivating), nesting, or traveling between wetlands.

seven baby turtles.

Mature female turtles lay a clutch of eggs on land, leaving them to hatch and overwinter in the nest. The hatchlings emerge the following spring and find their way to water. Credit: Joe Pignatelli/Washington Department of Fish and Wildlife

From May to August, mature female turtles lay eggs in a pear-shaped depression up to one-quarter mile from water. Larger females typically lay more eggs. When laying is done, turtles lightly cover the nest, leaving the eggs to hatch on their own. Hatchling turtles usually overwinter in the nest and venture into water the following spring. Survival is a challenge as many hatchlings and first-year juvenile turtles do not make it to the next life stage.

"As our only native freshwater turtle, western pond turtles play critical roles in our region’s aquatic ecosystems,” said Loggins. “With the help of our partners, we can spark community interest and leverage additional support for turtle conservation throughout their range.”

Both Loggins and Enders agree that collaborative efforts are key to ensuring future opportunities to see more pointy snouts with beady eyes peeking up from what looks like swimming rocks.

 

A juvenile western pond turtle makes a quick escape from biologists on a survey in the Trinity River in northern California last summer. Credit: John Heil/USFWS

 

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Susan Sawyer

About the writer...

Susan Sawyer is the Klamath Basin public affairs officer, covering the Klamath Basin National Wildlife Refuge Complex, Klamath Falls and Yreka Fish and Wildlife Offices. She was raised in the California desert gaining a deep appreciation of the outdoors on family vacations to the Pacific coast, Sierras and Redwood forests.

She has worked in Arizona, Nevada, Montana, Idaho and now Oregon, where she spends her free time landscaping for wildlife, continuing to learn from and about nature and spoiling her animals.

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Michelle Hunt

About the writer...

Michelle Hunt is a fish and wildlife biologist in the Reno, Nevada office. She loves the western desert landscapes and all of their diverse flora and fauna and her favorite plant is the saguaro cactus. In her free time, she enjoys hiking, mountain biking, and traveling to natural areas in the United States and Central America. She has a rescue dog named Winston who loves to get out and explore with her.