- JUNEAU, Alaska (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.
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- 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.
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- "We don't know what's causing the problem,"
said Colleen Handel, a wildlife biologist with the U.S. Geological Survey
(news - web sites)'s Alaska Science Center in Anchorage. She's been studying
the beak deformities for five years.
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- 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.
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- 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.
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- 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.
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- "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.
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- Tests on affected birds have shown no specific parasite
or disease, and only low levels of contaminants.
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- Besides caring for the health of Alaska's wildlife, there
are concerns about possible implications to humans, Handel said.
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- "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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