© U.S. Geological Survey and British Columbia Health MinistryU.S. officials believe an increasing number birds, including the ones in these photos are deformed, but don't know what's causing the problem
As for the birds, they were observers in the background. Now they may be paying a price for all that human activity in Alaska and along the Pacific Northwest.
A study released by the U.S. Geological Survey on Monday documents that scientists have discovered an unusually high rate of bird beak abnormalities. Actually, the highest rate ever. And while researchers have no idea why, some are already pointing the finger at the activities of mankind.
"The prevalence of these strange deformities is more than ten times what is normally expected in a wild bird population," said Colleen Handel of the USGS in an article published in The Auk, a quarterly journal of ornithology.
The birds are suffering from what is called "avian keratin disorder." That means the "keratin layer of the beak becomes overgrown, resulting in noticeably elongated and often crossed beaks, sometimes accompanied by abnormal skin, legs, feet, claws and feathers," according to the article.
Species particularly harmed by the phenomenon are adult black-capped chickadees in Alaska. Other species have been detected with similar problems in British Columbia in Canada as well as in Washington state.
Adult northwestern crows have been hard hit in coastal Alaska.
The malady makes it difficult for the birds to feed and clean themselves properly, affecting not just their health but possibly the long-term survival rate of the species.
"We have seen effects not only on the birds' survival rates, but also on their ability to reproduce and raise young. We are particularly concerned because we have not yet been able to determine the cause, despite testing for the most likely culprits," said Handel.
In similar situations elsewhere over the years, pollution and nutritional deficits turned out to be major contributors to such abnormalities. Once the problems were identified, steps were taken to protect the birds by reducing man-caused pollution.
This threat is broader than those seen in earlier years.
"We're seeing ecologically unique species affected across a wide range of habitats. The scope of this problem raises concern about environmental factors in the region," said USGS wildlife biologist Caroline Van Hemert.
The article, entitled "Epizootic of beak deformities among wild birds in Alaska: An emerging disease in North America?" and "Beak deformities in Northwestern Crows" Evidence of a multispecies epizootic" are available in the printed edition of The Auk.
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