WILDLIFE — Harassed in recent weeks by bald eagles, the world’s largest Caspian tern colony for the past decade “collapsed entirely” last week with the last of some 5,000 nests plundered, according to a report in the Columbia Basin Bulletin.
The constant hunting pressure from the eagles scared terns off their nests so much they were unable to raise their young.
The lower Columbia River island’s double crested cormorant colony, which is also believed to be the world’s largest, has also been besieged this spring by bald eagles, peregrine falcons and great horned owls.
The research updates are posted on Bird Research Northwest’s web site:
The level of “disturbance” caused by the bald eagles is unprecedented, according to researchers who have been monitoring the island since the late 1990s.
The tern colony has grown significantly since it was first documented in 1984 taking advantage of unnatural islands created by dredging.
The terns soon became a new major consumer of salmon and steelhead smolts.