By Rachel Sawicki

More than 50 songbirds in Delaware have been reported dead since mid-May, according to the Department of Natural Resources and Environmental Control.

Birds across at least six other mid-Atlantic and central states appear to have been struck by an inexplicable illness, causing erratic flight and stumbling with swollen eyes and crusty discharge.

European starlings, blue jays and common grackles have been identified as the most commonly afflicted birds thus far. Younger birds appear to be contracting the illness more than adults. DNREC is helping to investigate the cause of the unknown illness, according to a statement released Wednesday.

The United States Geological Survey confirmed in early June that they were investigating bird deaths in Washington, Virginia, Maryland and West Virginia from late-May Reports began to surface in Kentucky, Ohio and Indiana last week.

The symptoms of the mysterious sickness are unlike other symptoms of common bird illnesses. One that is most frequently seen in wild feeder birds is salmonella. Diarrhea, ruffled feather, and lethargy usually occur and sick birds die in one to three days.

Contaminated droppings infect healthy birds at crowded feeders. Avian pox is another viral disease that causes lesions and can prevent birds from finding food when sores are built up around the eyes. Most birds, however, recover.

Guy VanderLek of Wilmington keeps bird feeders and bird baths in his yard and said he recently found a few dead fledglings. He said it was strange that they were otherwise untouched.

“It is interesting that the fledelings were ignored by the neighborhood cats and the fox that transit our yard,” Mr. VanderLek said. “It’s like they knew it was not safe to eat them.”

Even so, DNREC says state and federal wildlife health experts advise pet owners to keep pets away from sick and dead birds and avoid handling wild birds themselves.

They suspect that congregating birds may contribute to the spread and are thus advising anyone that keeps bird feeders or bird baths refrain from refilling them until it is deemed safe to do so. Experts also suggest cleaning feeders and baths with a 10% bleach solution before reactivating them.

Any residents who see wild birds exhibiting symptoms of the illness should contact the Tri-State Bird Rescue & Research at 302-737-9543. Dead birds that appear to have the symptoms can be reported to DNREC at 302-735-3600.