Increase in Beak Deformities Could Signal Influx of Pollutants

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Bird's with strange, elongated, beaks, crossed beaks, elongated claws, and uncommon skin and feather coloration are turning up with increasing frequency in Alaska and the Northwest. The trend, dubbed "avian keratin disorder" by researchers, is alarming and, at the moment, its cause is unknown.

However, in the past, such outbreaks of mutations and deformities in birds have been linked with large environmental pollution events. Colleen Handel, a research biologist studying the trend, explained that "the prevalence of these strange deformities is more than 10 times what is normally expected in a wild bird population."

So far, Handel and her colleague Caroline Van Hemert, have documented 2,100 individuals with the disorder. They estimate that it affects 17 percent of the crow population in Alaska and the Northwest and 6.5 percent of black-capped chickadees—and their research shows that this number is rising.

Large clusters of deformities were associated with organochlorine pollution in the Great Lakes and selenium pollution in California. Researchers pointed out, however, that the cause of the current trend is unknown and could also be the result of a number of things, including nutritional deficiencies, and bacterial, viral, fungal, or parasitic infections.

Regardless of the cause, the deformities, which limit afflicted birds' ability to feed and preen, represents an alarming trend both because of the number of species affected and the geographical spread of cases.