Beavers brought here as part of an effort to improve ecosystems

SKYKOMISH — On a rainy Wednesday, a small team hiked into the woods near Skykomish hauling three heavy cages.

Their destination: a creekside pile of cut branches and sticks. Their cargo: a family of six beavers.

The first cage was lined up with an opening in the pile of wood, which is actually a lodge built by the team the previous Friday. The cage was opened and the matriarch of the family, weighing 50 pounds, was gently encouraged into the lodge.

Once she waddled in, one of the team called out, “Mama went in,” and a small cheer went up.

Mama beaver was followed by one of her young, then the cage was removed and the lodge entrance blocked to prevent the beavers from leaving while the next cage was lined up.

Within 10 minutes, the entire family — mother, father, three subadults about one year old and one kit — was in the lodge, the entrance blocked with a log.

It was a momentous occasion, because it’s the first time a family of beavers has been repatriated west of the Cascades. The Tulalip Tribes led the operation, but representatives from the state Department of Fish and Wildlife and the U.S. Forest Service were also on hand to watch, as were the communications departments from the tribes and the Northwest Indian Fisheries Commission, recording the event for posterity.

The beavers were found near Duvall, where their dam-building had caused flooding at a blueberry farm. The tribes captured them over several days and held them at their salmon hatchery for about 14 days before bringing them up into the mountains, said Jason Schilling, a wildlife biologist with the Tulalip Tribes, who are releasing beavers into the western Cascades as part of a long-term watershed management program.

Almost immediately after the release, the beavers began a soft high-pitched cooing inside the lodge, probably a comforting sound for the family recently reunited after several stressful days of travel.

“It’s basically like an alien abduction,” said Ben Dittbrenner, a Ph.D. candidate in forest ecology at the University of Washington working with the Tulalips on this project. “They are really stoic, but they get stressed really easily.”

Someone asked Molly Alves, an assistant biologist with the tribes, if she’ll miss them.

“Yes,” she said with a smile. “My furry children.”

Capturing and releasing beavers is regulated under state law (the 2012 “Beaver Bill”), but, as written, it only allows releases east of the Cascades.

In this case, the state recognized the Tulalips’ treaty rights to release them west of the mountains as part of the tribes’ watershed management programs, Schilling said.

Beavers play an important role in maintaining stream health. Their dams help maintain a consistent base flow of water in streams so that it doesn’t all flow downhill in one springtime deluge, an important consideration in eastern Washington where many streams run dry in the summer.

Beaver dams also retain sediment and help to reduce water temperatures in streams, making them healthier for salmon and other fish.

Dittbrenner said this work will also help prove a theory in his dissertation.

“What we’re hoping to show is that the beavers can be used to reduce the effects of climate change,” Dittbrenner said.

One of the major impacts expected from climate change in the Pacific Northwest is warmer water at higher elevations. That will lead to less snowpack, and therefore less water from snowmelt in streams in the summer, presenting risks to salmon and fish habitat.

Beaver activity resaturates the land, however. Stored water migrates downstream more slowly, and often through the water table, which keeps the temperature down.

Beaver activity has also been shown to correlate with more stream meanders, more shady spots, and overall more diverse ecosystems, Dittbrenner said. In other studies, juvenile coho salmon were seen in higher numbers in streams with beavers.

“Beavers and coho go hand in hand, or foot and tail,” he said.

In the end, he hopes to measure overall effects of beavers on their ecosystem, and he predicts that they will be shown to have a positive impact.

“We can’t stop climate change, but we can help build ecosystem resilience,” Dittbrenner said.

The tribes kept the captured family beavers for about 14 days: long enough to break their desire to return to where they were captured, but short enough to minimize the amount of stress they were placed under.

The new lodge has a “back door,” an opening blocked by a number of sticks like prison bars that the beavers can easily chew through.

The idea is to let the beavers settle in the artificial lodge and begin to feel safe before they venture out for food.

Eventually they might migrate elsewhere and build a new lodge, Schilling said, but the artificial construction gives them a place to hide from predators like cougars and coyotes while they get acclimated to their new home.

Three infrared wildlife cameras were installed to start recording when the beavers were expected to emerge that evening.

Instead, the mother beaver chewed her way out while the cameras were still being set up and started eating from a nearby blueberry bush, Schilling said. The family does appear to be staying together, however, which is a good sign.

“They have pretty strong family units,” he said.

The goal is to populate eight sites in the mountains this year, and another eight next year, with beavers captured in the lowlands. A similar number of water systems won’t receive beaver populations, so the two can be meaningfully compared.

The tribes have since captured a pair of subadult beavers near the Highway 520 bridge in Bellevue, and an adult female near Twin Lakes.

The two young beavers were found huddled together in a shallow nest with no cover, completely exposed to nearby construction noise and highway traffic. One had pneumonia and was being treated at the PAWS Wildlife Center.

There’s no shortage of nuisance beavers in the lowlands, Dittbrenner said, and the tribes are making efforts to capture and relocate only those beavers that would otherwise likely be trapped and killed.

“We want to keep them in as many places as possible,” Dittbrenner said.

Chris Winters: 425- 374-4165; cwinters@heraldnet.com. Twitter: @Chris_at_Herald.