Beak deformities increase in Northwest

http://news.yahoo.com/s/ap/20101109/ap_on_sc/us_deformed_beaks;_ylt=Ao_wDBvb3ptdDG6x992GScEPLBIF;_ylu=X3oDMTJpNW1wOW8zBGFzc2V0A2FwLzIwMTAxMTA5L3VzX2RlZm9ybWVkX2JlYWtzBGNwb3MDMQRwb3MDMgRzZWMDeW5fdG9wX3N0b3J5BHNsawNmdWxsbmJzcHN0b3I-

By DAN JOLING, Associated Press Dan Joling, Associated Press – Mon Nov 8, 11:28 pm ET

ANCHORAGE, Alaska – Scientists have observed the highest rate of beak abnormalities ever recorded in wild bird populations in Alaska and the Northwest, a study by two federal scientists said.

The U.S. Geological Survey study on beak deformities in northwestern crows in Alaska, Washington and British Columbia follows a trend found earlier in Alaska's black-capped chickadees.

"The prevalence of these strange deformities is more than 10 times what is normally expected in a wild bird population," said research biologist Colleen Handel.

Handel and wildlife biologist Caroline Van Hemert published their findings in The Auk, a Quarterly Journal of Ornithology. They captured Alaska crows in six coastal locations and used documented reports and photographs for birds elsewhere.

The cause of the deformity — called "avian keratin disorder" — hasn't been determined, Handel said. An estimated 17 percent of adult northwestern crows are affected by the disorder in coastal Alaska.

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Van Hemert said the disorder first was noticed in significant numbers around 1999. It has increased dramatically over the past decade, affecting 6.5 percent of adult black-capped chickadees in Alaska annually.

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The scientists said beak deformities can be caused by environmental contaminants, nutritional deficiencies, and bacterial, viral, fungal or parasitic infections.

In the past, large clusters of beak deformities have been associated with environmental pollutants such as organochlorines in the Great Lakes region and selenium from agricultural runoff in California.

The deformities affect birds' ability to feed, Van Hemert said, though many birds appear to cope by relying on food provided by humans at feeders rather than foraging.

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