JUNEAU (AP) A bird beak deformity first recorded among black-capped chickadees near Anchorage has been increasingly seen in crows in Southeast Alaska, broadening an already mysterious phenomenon.
Black-capped chickadees, northwestern crows and 27 other species of birds in Alaska have 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.
''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. She's been studying the beak deformities for five years.
Though the phenomenon was first noticed in black-capped chickadees in the early 1990s, a deformed raven, a deformed Steller's jay and several deformed crows have been reported in Southeast Alaska since 1997.
Southeast sightings have increased this year, biologists told the Juneau Empire.
A black-capped chickadee with a deformed beak is shown in this December 1998 Bird Treatment & Learning Center photo, in Anchorage.
AP Photo/Bird Treatment & Learning Center
The center has received 1,600 reports of deformed black-capped chickadees beaks in Alaska and 200 reports of other kinds of birds in Alaska, compared with only 12 reports of beak deformities of black-capped chickadees in the rest of North America. Handel had no total for other deformed birds elsewhere in North America but said nowhere is there a concentration as in Alaska.
Those deformities could have been caused by genetic mutations. Damaged DNA could be implicated in the abnormal growth, Handel said, but no one knows what might be causing damage to the DNA.
''With such a broad geographic range, you look for something that could be occurring over a broad area, and that immediately calls to mind something like contaminants or a disease organism that could be affecting a large area,'' Handel said.
Tests on affected birds have shown no specific parasite or disease, and only low levels of contaminants.
Besides caring for the health of Alaska's wildlife, there are concerns about possible implications to humans, Handel said.
''In the back of my mind I always wonder what else might be affected, depending on what's causing it,'' Handel said.
''... If there's something happening to those species, it's certainly something that raises an alarm for all of us.''
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