Summary
A mysterious deadly disease in the eastern United States has been killing wild birds, which suffer neurological problems and crusty, oozing patches over their eyes. Since May, researchers have documented hundreds of cases in at least a dozen species of birds in nine eastern and midwestern states. State, federal, and academic scientists are hunting for clues to a cause in bird carcasses and the environment. In May and June, portions of the outbreak area saw the emergence of billions of periodical cicadas, members of the 17-year Brood X. Birds feast on cicadas, prompting some researchers to wonder whether the outbreak might be linked to the insect contamination with pesticides or a deadly fungus. But the cicadas appear to be blameless. On 2 July, the U.S. Geological Survey’s National Wildlife Health Center also ruled out several pathogens that cause mass mortality in birds, including Salmonella bacteria, several families of viruses, and Trichomonas parasites. At this point, the outbreak doesn’t appear to pose a serious threat to bird populations, researchers say, but officials are asking the public to bury dead birds and take down feeders.