Black-Capped Chickadee in Homer, Alaska (image) California Academy of Sciences Share Print E-Mail Caption AKD can severely impact a bird's ability to preen -- a behavior crucial to its survival. Here, a black-capped chickadee with a curved beak sits on a branch in Homer, Alaska. Credit © Martin Renner Usage Restrictions Photos are available for editorial use only. Credits provided above are mandatory. Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.