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Black-capped Chickadee with elongated upper beak

By Alaska Science Center
Chickadee with a deformed beak in a bush
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Detailed Description

Black-capped Chickadee with elongated upper beak. Avian keratin disorder (AKD) is a disease characterized by debilitating beak overgrowth and other abnormalities of keratinized tissues. Affected birds have difficulty feeding and preening and may suffer high rates of mortality.

Sources/Usage

Public Domain.