Mysterious Bird Disease Disappears but Threats Persist

Screenshot of Audubon article about the bird disease disappearing.
Screenshot of Audubon article.

By Frank Gallagher, NANPA Blog Coordinator

Earlier this year, birds started coming down with swollen eyes and “crusty discharges,” neurological symptoms, and blindness which all too often led to death. The disease spread quickly through 11 mid-Atlantic and Great Lakes states, as far south as Florida and as far west as Indiana, prompting state wildlife agencies and Audubon chapters to urge people to take down feeders. Bodies of dead birds were sent to labs for analysis, hoping to pinpoint the pathogen responsible. To date, there has been no firm diagnosis. As the summer ended, so did reports of ill birds. Just as swiftly and mysteriously as it started, so this disease seems to be abating.

In the last few weeks, the Washington Post, Philadelphia Inquirer, and Audubon (among many) have reported that the outbreak has virtually ended. State wildlife agencies ended their recommendations to take down feeders but currently recommend weekly cleaning feeders weekly with soap and water, followed by a rinse with a 10 percent bleach solution.

While there is no proof that feeders or birdbaths spread the disease, biologists were concerned that birds gathering at such locations could spread the illness through proximity. In spite of a multi-state collaborative effort between wildlife agencies, universities and laboratories, no cause has been identified. For a while, since the disease seemed to coincide with the emergence and life cycle of Brood X cicadas, but birds were dying in areas far beyond the range of the brood.

It’s not like that was the only threat faced by our avian friends. Birds are under threat the world over, primarily from climate change and habitat loss. In Europe, a recent report found one in five bird species are at risk of extinction. Meanwhile, an Audubon study from 2019 found two-thirds of North American bird species are at increasing risk of dying out while a second study documented the loss of almost 3 billion birds, almost a third of the total population, over the past 50 years.

So, put your backyard feeders out again but also do what you can to plant native species, avoid non-native plants, and create a patch of friendly habitat. When we put our minds to it, we can often save threatened species. The Cornell Lab of Ornithology (the people behind the Merlin app) recommend Seven Simple Actions to Help Birds.