Red-breasted Nuthatch with an elongated deformed beak

Female Red-breasted Nuthatch with an elongated beak. It was captured in Anchorage as part of the beak deformity research project. 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.