Beak Deformity Spreads Among Alaskan Birds

A bird beak deformity first recorded among black-capped chickadees near Anchorage has been increasingly seen in crows in Southeast Alaska, broadening a mysterious phenomenon. Twenty-nine species of birds in Alaska have now been reported with beaks up to three times their normal length. The deformity often strikes mature birds and reduces their ability to feed and preen effectively. In many birds, the deformity leads to death.

Tests on affected birds have shown no specific parasite or disease, and only low levels of contaminants. “We don’t know what’s causing the problem,” said Colleen Handel, a wildlife biologist with the U.S. Geological Survey’s Alaska Science Center in Anchorage.