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.
…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.
…The increasing occurrence of deformities in multiple bird species with broad geographic distribution suggests that avian keratin disorder is spreading, they said.