Birds are dying in the United States and no one knows why

There's a new epidemic, this time among birds. An illness is infecting them in the US capital ― and it's spreading. Experts say the cause is unknown.

While humans and other animals continue to grapple with COVID-19, a new epidemic seems to have hit multiple bird species in North America.

Across the United States, people have been finding dead birds. The birds appear to have been hit by a wave of mysterious illnesses since April.

Ornithologists (bird experts) say the dead or ailing aviators tend to have swollen eyes as well as neurological issues that seem to be causing the birds to lose balance.

"It’s not unusual to see birds with eye problems," says Jim Monsma, director and founder of the animal rescue center City Wildlife in Washington, D.C.

Monsma has worked in animal protection and rehabilitation within urban areas for 25 years, especially in the D.C. area.

But it took Monsma and his colleagues a while to realize that what they were seeing was "not usual."

"We didn’t know at first we were dealing with an epidemic," Monsma says.

Looking for the cause

They now think that multiple bird species have been contracting an odd illness for about two months. And the illness has spread at least 965 kilometers (600 miles) from the capital, across the Midwest regions of the United States and into the state of Indiana.

The United States Geological Survey (USGS) published a report on the mysterious bird deaths in early June. Details remain hazy,