About one in 16 crows and black-capped chickadees suffer from a condition called avian keratin disorder, which causes their beaks to become morbidly elongated and crossed.
Rates of the debilitating disorder are 10 times higher than usual. That’s higher than has ever been recorded in any wild-bird population, and most of this rise happened over the last decade. Dozens of other bird species are afflicted. Nobody knows why, but it’s probably not a good sign.
“The sudden appearance of a large cluster of animals with gross abnormalities may signal a significant change in an ecosystem,” wrote U.S. government biologists Colleen Handel and Kimberly Trust in paper published in October in The Auk.
Many possible culprits have been identified. One is environmental contamination; toxins and heavy metals have caused past beak-deformity epidemics in the Great Lakes and California. But those outbreaks occurred in clusters, while Alaska’s deformities are widespread and affect species living in different habitats, with different diets.
Read more at Wired
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