Mostly Trapping

Beavers are active in Mercer Island Park
Feb 22, 2019 08:57 ET

(Reprinted from above link)

Before snow blanketed the city’s parks, visitors to Luther Burbank on Mercer Island noticed some other phenomena of nature, including fallen tree branches and gnawed-on trunks near the shore and wetlands.

The 77-acre park on the shores of Lake Washington is a rest stop for many species of migratory birds, and is home to at least one family of beavers. Islanders have recently noticed their handiwork on some of the Poplar trees near the shoreline.

Kim Frappier, the city’s natural resources specialist, said that she and the park’s urban forestry specialist “are monitoring the beaver activity within the park and working to both protect the beaver’s habitat as well as take measures to protect high value trees along the shoreline.”

Frappier also addressed the “eager beaver” activity in the Parks and Recreation department’s January Newsletter.

“Mercer Island is home to a busy and very eager colony of beavers (aka Castor canadensis),” she wrote. “The beavers at Luther Burbank continue to work on their lodge and dam in the wetlands near the shore of Lake Washington.”

Long-time residents of Washington state, beavers are the largest living rodents in North America, she wrote, and have a broad, flat tail, webbed hind feet and large orange incisor teeth.

“Probably no animal leaves more obvious signs of its presence than the beaver. Freshly cut trees and shrubs, and prominent dams and lodges are sure indicators of their activity,” according to the Washington Department of Fish and Wildlife.

They build their lodge or bank den as a safe place to rest, give birth, and raise their young — safe from predators, she wrote. Beaver dams and the trees they fell create habitat and resting spots for many other plants and animals, like frogs, herons and insects.

Much of Luther Burbank Park has been left undeveloped to foster a variety of wildlife, including 135 species of birds, 50 species of waterfowl, raccoons, beaver, muskrats, tree frogs and rabbits. Many of these animals live in the wetlands that occupy the north and south ends of the park.

Frappier also shared some educational facts about beavers in the newsletter, for example, that a mated beaver pair will often mate for life. Beaver litters usually have one to eight kits born between April and June, and beavers are nocturnal, often active just before sunrise and after sunset.

Beavers eat the leaves, inner bark, and twigs of alder, birch, cottonwood, willow and other deciduous trees. They also nibble on shrubs, ferns, aquatic plants and grasses.

“Conifers are not a favorite food, but mainly felled for building material or to encourage growth of their preferred foods,” she wrote.

The beaver’s famous incisors (front teeth) grow continuously. They are harder on the front surface than on the back, and so the back wears faster, which creates a sharp edge that enables a beaver to easily cut through wood.

Beavers were once nearly eradicated due to high demand for their pelts. But thanks to a decreased demand for pelts and a shift in trapping laws, beavers have made a comeback. Neighbors can help by giving the animals space.

“Please help us protect our long-toothed furry neighbors by staying on established trails, protecting and respecting their habitat, and observing them from a distance,” Frappier wrote.

Mercer Island is graced with 35 parks, over 400 acres of natural areas and more than 50 miles of trails. Volunteers have been improving these parks for many years, planting native trees and shrubs and removing invasive plants but much more work remains to be done.

There are forest restoration events scheduled for almost every Saturday in 2019. For more, see or contact Frappier at