Friday, December 6, 2013

Those strange new trees on SR 520? They’re for the birds

By guest blogger Kate Elliott, Eastside Corridor Constructors

This raptor perch, or “snag”, located just east of the
Bellevue Way bridge over SR 520 in Bellevue is an
ideal hunting perch for birds of prey.
If you’re used to seeing evergreens along Western Washington roadways, you may have noticed an odd sight as you travel on SR 520 near Bellevue Way: a group of 20 seemingly lifeless trees.

This fall Eastside Corridor Constructors, the contractor building the SR 520 Eastside Transit and HOV Project, added the salvaged spindly evergreen trees just east of the Bellevue Way overpass to provide perches for birds of prey, including owls, eagles and hawks. Adding these perches is part of the 520 project’s efforts to restore animal habitat along nearby Yarrow Creek.

I chatted with Ken Otis, the environmental superintendent for ECC, and he said that while the trees may look unconventional, this is just what critters need to thrive in this urban environment. He’s proud that we’re taking these extra steps to sustain the environment in the middle of a construction zone. Birds and bats alike will hunt and roost for years to come.

While not the handsomest tree you’ll ever see, the perches are attractive to Western Washington’s abundant population of raptors, like Red-tailed and Cooper’s hawks. And this habitat not only serves birds but also mosses, lichens and insects that will consume the wood and hide in the bark.

Adding these perches is part of the project’s
efforts to restore animal habitat along nearby
Yarrow Creek.
Michael MacDonald, WSDOT’s National Marine Fisheries Service liaison, told me that the added features make for a more holistic environment than merely building a pond that could quickly be overrun with bullfrogs and blackberries, along with other animals and invasive plants.

To keep these perches – or “snags,” as biologists call them – upright, crews buried them at least 4 feet in the ground. In 15 to 30 years, after the landscaping has matured a bit, the perches will eventually fall to the ground to become woody groundcover. Crews placed each perch so that it will fall into the habitat area – and away from the nearby roadways.

Later this year, crews will mount bat houses on the side of the perches to house some of the 11 species of bats in Western Washington that roost in fabricated structures. Although these perches look odd now, next spring crews will plant native trees and shrubs to provide cover for the perches and excellent hunting grounds for the birds.


Anonymous said...

I can't help but be concerned about the design life of these perches: it seems like it is greater than that of the 520 bridge.

Anonymous said...

This is wonderful news! Thank you for thinking of all the wildlife, I hope this helps them secure a continued presence.

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