Sep. 2—OTHELLO, Wash. — Some of the frogs leapt straight into the water. Some tried to eat. Others headed for the fence, trying to scale it and escape the small pen made for them.
The 300 northern leopard frogs had just spent months growing up at the Northwest Trek Wildlife Park in Eatonville, Washington. Then, on Wednesday, they spent a few hours in plastic totes in the back of a van as they were hauled over the Cascades and into the Columbia National Wildlife Refuge, where they were released at the edge of a shallow pond.
Each frog embraced its newfound freedom in its own way — leaping, eating, swimming, climbing. Some just held still in the grass, almost looking confused.
Now, there's really only one task left.
"We just need them to live," said Lindsey Nason, a biologist for the Washington Department of Fish and Wildlife. "Please live."
The release Wednesday night marked the third year of a project meant to establish a new population of the northern leopard frogs, which have been listed as endangered in Washington since 1999.
The frogs grow to 3 or 4 inches in length. They're usually brown or green, and they have distinct spots on their backs.
They were once found throughout North America. But over the past several decades, populations have tanked, especially in the West. Habitat loss, climate change and predators like invasive bullfrogs are among the factors that led to the decline.
WDFW's website says the species once occupied 17 sites throughout the eastern half of the state, including in northern Spokane County and in Pend Orielle County. Now, however, just one wild population remains, at Potholes Reservoir.
That's why WDFW has been working to reintroduce the frogs here, in these desert wetlands south of Moses Lake. Additional populations would give the species a better chance of staving off extinction, Nason said.
"It's just very precarious to have them existing in just one place," she said.
WDFW gathers egg masses from the wild population each spring, then sends them off to be raised in captivity. Raising them elsewhere before returning them to the wild is meant to keep them safe from predators like bullfrogs and other challenges, like habitat degradation.
The agency has worked with both Northwest Trek and the Oregon Zoo to raise the frogs over the past few years, and they've released hundreds of them into the wild.
But a new population has yet to take hold.
Nason said biologists have seen the frogs throughout the fall, but when spring comes around, they're gone. They assume the frogs died over the winter, or that so few of them lived, it's all but impossible to find them.
"All we know is we can't find them," Nason said.
The hope is that the frogs released this year will break that trend.
The 300 frogs raised at Northwest Trek represent a significant increase in the number of frogs they've released. Last year, the organization brought 124 frogs to WDFW for release.
Chelsea Hicks, one of the Northwest Trek staffers who helped raise the frogs, said they start by simply taking care of the eggs, making sure they're in good conditions. When the eggs become tadpoles, they start feeding them a plant-based diet of specialized gels and algae wafers. When the frogs grow legs and absorb their tails, they begin feeding them insects, like crickets and mealworms.
While the frogs grew, Nason worked with the U.S. Fish and Wildlife Service to ready the pond for the release. The frogs like shallow water and short vegetation, so the refuge drained some of the water out of the pond and mowed down the shoreline. A waist-high fence was built around the pond to try to keep bullfrogs out.
A couple of hours before dusk on Wednesday, Nason led a convoy of vehicles into the scablands of the refuge to reach the release site. At the first spot, the group hauled five totes carrying the frogs into a small pen along the shoreline, fenced off to help the newcomers settle in.
Then, they lifted the lids and tipped the totes forward, offering words of encouragement as they coaxed the frogs into their new home.
The process repeated itself a few minutes later at a different site on the pond, a move meant to keep from putting too many frogs in one particular spot.
All of the frogs released were injected with a dye, which will tell biologists who find them later where the frogs came from. They don't have a good way of tracking the frogs' movements, Nason said. An attempt at using radio tags in years past failed — the tags fell off the frogs.
On Sunday, Nason planned to return with a graduate student from Washington State University. They will gather about 10 or 15 frogs and test their response to the approach of humans — basically, they'll see how close they can get before the frogs jump away. The idea is to see whether the response from the frogs raised in captivity is different from that of the wild frogs.
Not long after that, Nason will disassemble the pen and let the frogs have full access to the pond.
Throughout the fall, she'll go back and check on the frogs. Another few hundred raised at the Oregon Zoo were released earlier this month, so assuming all goes well, she'll have a little more than 600 frogs to look for.
Come spring, she hopes they'll still be alive.