In late April, scientists and the public noticed something odd about the birds in the mid-Atlantic region: A surprising number were exhibiting strange symptoms, such as crusty eyes or shaking heads. The birds were often sick or dying. Scientists refer to this as a “mortality event” — when a large number of animals die in a relatively short period of time due to what appears to be a common cause. Birds that seem to be affected include blue jays, starlings, robins, wrens and cardinals. Right now, it seems that the birds in the mid-Atlantic region are the hardest hit, but similar cases have been reported across the country. The cause of the deaths remains a mystery, but scientists are still collecting data and exploring a number of potential causes. When there’s not an obvious cause, the first things researchers look at is changes in the environment. This year, the only obvious change is the 17-year Brood X cicada emergence. Many songbirds in the region ate a lot of cicadas in May and June. That means they were exposed to high levels of whatever is in the cicadas. Even low levels of toxins in the cicadas are magnified when a bird eats hundreds of them. The toxins come from fungus, pesticides, or anything else in the environment that the cicadas were exposed to over the past 17 years. Scientists are now asking the public to help by taking down and cleaning their bird feeders and birdbaths in case the deaths are linked to a contagious disease.
