Why did the red-legged frog cross the road?


Most rainy nights this year, volunteers have stood on guard at the edge of Highway 30 near Linnton.

TLC helps frogs cross busy Highway 30

By Allan Classen, NW Examiner, MARCH 2014 / VOLUME 27, ISSUE 7

Their mission? Save northern red-legged frogs, who are driven by nature to cross the four-lane highway to reach spawning ponds along the Willamette River. Without help, the frogs’ chances of evading traffic and getting across the highway are slim. That tendency, plus the fact that nearly every type of predator is after them, has led to their inclusion on the Oregon “sensitive species” list, one step above endangered.

Shawn Looney saw what could happen last winter and couldn’t take it. On her way to an evening meeting, she drove over clusters of frogs on Harborton Road, which leads to the highway.

“When she arrived, she was a little bit hysterical,” said Rob Lee, who like Looney is active in the Linnton Neighborhood Association. When they returned together to assess the damage, “She was even more hysterical. There were frog bodies all over the road.

“We counted 60 dead frogs on Harborton the next day,” he said. “They were just being slaughtered.”

If that could happen on Harborton, a narrow side road, what about Highway 30? Lee checked it out and found more of the same. He counted at least 100 in close proximity on the pavement.

“They were all being squished by vehicles,” he said.

A plan of action was needed. Last fall, Lee met with state of Oregon wildlife biologists, the Portland Bureau of Environmental Services and the West Multnomah Soil & Water Conservation District.

The chair of the WMSWCD, Jane Hartline, organized volunteers for the next breeding season, which runs roughly from early January to mid-February. The frogs don’t move until it’s dark, rainy and at least 45 degrees, they learned. This winter, a crew of crossing guards was ready for them. Hartline recruited about 35 volunteers, and many were on duty Jan. 7 when a huge migration—365 were counted—made their move. The volunteers soon learned that the frogs were “surprisingly compliant” and could easily be picked up and dropped in 5-gallon buckets.

“Mostly, they jump out on the road and just sit there,” said Hartline.

Alex Dolle gives a helping hand; photo by Jane Hartline

Alex Dolle gives a helping hand; photo by Jane Hartline

Still, when they come in waves, “It can be nerve wracking if you don’t have enough people,” said Lee.  “When it really happens, there are frogs all over the place.”

The loaded buckets were driven to a marina near the river’s edge, where the frogs lay their eggs. The tadpoles hatch and spend a few months growing before heading to the forest. Like salmon, they return as adults to lay their eggs in the place they were born. Some nights are too cold for the frogs, and on many nights, only a handful try to cross. But whenever weather conditions are right, volunteers gear up for a long wet night—sometimes for a few hours, sometimes past midnight. By mid-February, Lee said he had been out 23 nights. Getting the frogs to their spawning pools is one thing; getting them back come to the forest is another. Lee said he now sees frogs making the return trip.

Ultimately, a better way might be found. The volunteers, who include state wildlife biologist Sue Beilke, are carefully collecting data to understand their amphibious friends. A breeding pond on the forest side of the highway would be ideal, but finding a flat, open space to build such a pond may be easier said than done. A tunnel under or bridge over the highway seems far too expensive. So against all odds, rain or cold, the volunteers soldier on.

Hartline is particularly touched by the dedication of Beilke, who is out almost every night.

“Every time a frog is squashed, she says, ‘Oh no!’ which I love about Sue,” said Hartline.

Lee understands how the little creatures can grow on people.

“The frogs are very interesting and quite beautiful,” he said. “I’m amazed at how much personality they have.”

Their cause is also growing.

“I had no idea it would become anything like this,” said Lee. “It does touch a nerve with people. It’s been kind of inspiring.”

Neighbors know what’s going on and slow down near the crossing zone. He also gets plenty of ribbing about the frog migration assistance project, and he gets it. Some have suggested it could make a Portlandia episode.

“It’s pretty hilarious,” he said, “standing out in the cold and rain and waiting for frogs.”