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The Spokesman-Review Newspaper
Spokane, Washington  Est. May 19, 1883

Salt, deicer used on passes affecting birds

Associated Press The Spokesman-Review

STEVENS PASS, Wash. – The harsh winter pummeling Washington’s mountain passes isn’t easy for the birds either, it seems.

The road salt and deicer used on the state’s roadways tend to disorient finches and other small, seed-eating birds that ingest them as they peck for grit. That, in turn, makes them roadkill when they’re hit by snowplows and other vehicles.

Heather Murphy, a retired U.S. Forest Service wildlife biologist and consultant for the Wenatchee and Okanogan National Forest, said she noticed the problem while conducting bird studies for a Leavenworth volunteer birding group, the Upper Basin Birders.

Volunteers found three areas of dead finches last weekend on U.S. Highway 2, a half-mile west of the Stevens Pass summit. Murphy said they found fewer than a dozen birds at each site, although greater numbers were reported earlier in the winter.

The problem is unusual but quite severe this year, especially along U.S. 2 near Stevens Pass and Interstate 90 near Snoqualmie Pass, said Dan Stephens, a Wenatchee Valley College biology professor.

The finches are mainly attracted to the grit on and along the highway. In the process of picking up the grit needed to aid their digestion of seeds, they ingest salt and other deicer chemicals used to keep the roads free of ice, he said. The chemicals then cause disorientation and sluggishness.

The state Department of Transportation uses a liquid magnesium salt deicer as well as calcium chloride salt on mountain highways to control buildup of ice and snow.

The Transportation Department is aware of the bird problem, but isn’t sure what can be done about it, said Kelly McAllister, a department biologist in Olympia.

McAllister said he’s been studying the situation to try to understand why large numbers of birds are on the highway. He believes an unusually large number of finches – mainly the pine siskin, red crossbill, white-winged crossbill and Cassins finch – stayed in the area through the winter because of an abundant crop of pinecones this year. The finches feed on the seeds from the cones, but they need to also ingest small pebbles and grit to help break down the seeds in their gizzards before the seeds pass to their stomachs. The sand on the road is a good source of grit, especially in this particularly snowy year when there are few patches of bare ground to be found at higher elevations, he said. The state will continue to study the problem, McAllister said, but it’s unknown what alternatives exist.