CLARKSTON, Wash. -

The Army Corps of Engineers this spring will begin killing birds at some Snake and Columbia river dams to help protect juvenile salmon and steelhead.

The agency unveiled a plan Thursday that will allow as many as 1,200 California gulls, 650 ring-billed gulls and 150 double-crested cormorants to be killed.

The Lewiston Tribune says the action will occur at McNary Dam on the Columbia River and Ice Harbor, Lower Monumental, Little Goose and Lower Granite dams on the Snake River.

The corps says birds are typically the single largest cause of juvenile salmon and steelhead mortality. A 2009 study estimated that between 4 percent and 21 percent of smolts passing through the dams are eaten by birds.

The corps has long used non-lethal methods to scare away birds.