An American robin pauses while foraging during a recent warm summer day in Dickinson County. Robins are among the species that seems more susceptible to a mystery illness that is sickening songbirds in several eastern states. (Iron Mountain Daily News photo)

IRON MOUNTAIN — A baffling illness killing songbirds in parts of the eastern U.S. has wildlife experts advising the public monitor what they see at backyard feeders — or perhaps for now cease feeding altogether.

The mystery malady — described as lethargic birds with swollen, crusty eyes and impaired neurological functions, including seizures and loss of coordination — has been identified since late May in Washington D.C., Virginia, West Virginia, Kentucky, Ohio, Indiana, Maryland, Delaware, New Jersey and Pennsylvania, according to the Wisconsin Department of Natural Resources.

For now, no bird in Wisconsin has been confirmed to have this new ailment, the DNR stated in a news release Friday, adding that other conditions can have similar symptoms. House finches, for example, are known to contract a bacteria that causes conjunctivitis with swollen, red, crusty eyes and near blindness.

Yet the DNR recommended residents clean and disinfect all feeders and bird baths “regularly with soap and water, followed by a rinse in 10% bleach solution.”

The Madison Audubon Society in Madison, Wis., went a step further, posting a call on its website to take down all feeders — including hummingbird and suet — “out of abundance of caution,” adding enough natural food is available for the birds during the summer months. The society recommended as well cleaning the feeders and allowing them to air-dry but not rehanging, even while empty.

If bird baths are left out, as birds may need a water source during summer, they should be cleaned daily with a 10% bleach solution, air dried and refilled with clean, fresh water, according the Madison Audubon Society.

The Wisconsin DNR also asks that any sick or dead birds with clinical signs be reported.

“Several wildlife laboratories, including the National Wildlife Health Center in Madison, are working to identify the cause or causes of these cases,” DNR wildlife veterinarian Lindsey Long said. “These symptoms can be from multiple causes, so these groups have been conducting expansive testing. As part of our continued monitoring of wildlife health, we ask Wisconsinites to report birds with swollen or scabbing eyes so that we may investigate further. Sometimes, we may ask to collect these birds for testing.”

A National Public Radio story by Jeff Brady stated several species of birds have been affected, according to the University of Pennsylvania: blue jay, European starling, common grackle, American robin, northern cardinal, house finch, house sparrow, Eastern bluebird, red-bellied woodpecker, Carolina chickadee and Carolina wren.

“We did see really large numbers of grackles and blue jays, in particular, and they were all younger,” said Belinda Burwell, a veterinarian quoted in the NPR story who founded the group Wildlife Veterinary Care in Virginia, adding the birds “would swing their head very slowly, back and forth.”

So far, most cases involve four species: grackles, blue jays, robins and starlings, a July 2 statement from the U.S. Geological Survey’s National Wildlife Health Center declared, according to the journal Science.

Early research on the dead birds has ruled out salmonella, several families of viruses and Trichomonas parasites, according to the Science magazine story.

The affected states did suggest a potential suspect. In May and June, parts of the outbreak area saw billions of 17-year Brood X periodic cicadas emerge from underground, where they may have accumulated pesticides or other contaminants, according to Science.

But sick birds have been observed in areas where cicadas were rare as well.

“It does not look like it’s a match,” Brian Evans, a migratory bird ecologist with the Smithsonian’s National Zoo and Conservation Biology Institute, stated in the Science story.

Michigan’s Lower Peninsula was on the far western edge of the cicada outbreak, yet the illness so far has not been reported in Michigan. The Michigan DNR is monitoring the situation, said Holly Vaughn, DNR public outreach and engagement unit manager, according to writer Emily Bingham of mLive.

So what should be done here in the Upper Peninsula? It never hurts to regularly clean bird feeders. The Cornell Lab of Ornithology’s All About Birds website recommends taking feeders apart and use a dishwasher on a hot setting or hand washing, either with soap and boiling water or with a dilute bleach solution of no more than 1 part bleach to 9 parts water. Feeders should then be rinsed thoroughly and allowed to air dry — in sunlight, if possible — before refilling.

Those who come across a bird in Michigan they think has a serious illness should report it to the DNR’s online Eyes in the Field page or call the Michigan Department of Natural Resources Wildlife Disease Lab at 517-336-5030.