More than 100 black vultures have been found dead near the Conowingo Dam since mid-April after an outbreak of the highly pathogenic avian flu, officials say.
The discoveries have resulted in the closure of several walking trails in the area, as officials work to curtail the spread of the deadly virus among birds. The risk to humans remains low, according to the Centers for Disease Control, though one poultry worker tested positive for the avian flu in Colorado last month. That worker, the first human case of the virus in the U.S., has since recovered.
Since its arrival to the United States, the virus has swept through domestic flocks, and millions of birds have been culled. Locally, the Maryland Zoo in Baltimore opted to take many of its bird species off-exhibit to ensure they wouldn’t come into contact with infected birds or their droppings.
This came after several cases of the virus were reported among poultry on Maryland farms in March — one in Queen Anne’s County and one in Cecil County. But no cases have been reported in Maryland since, according to the Maryland Department of Agriculture’s website. Cooking meat and eggs to an internal temperature of at least 165 degrees Fahrenheit kills the virus, called H5N1, according to the CDC.
Near Conowingo, Constellation officials say they’re working closely with state and federal agencies to “protect the public, and wild and domestic birds in the area, including the area’s beloved eagles,” according to a news release.
“It’s just an unfortunate situation,” said Ted Evgeniadis, who serves as riverkeeper for the Lower Susquehanna, which hosts the dam. He recommended hikers visit the Susquehanna State Park nearby for other walking trials.
Officials opted to close the trails — the Mason Dixon Trail from Fisherman’s Park to Shuresville Road and the Shure’s Landing Wildflower Trail (also known as the Lower Susquehanna Heritage Greenways Trail) — mainly so that hikers wouldn’t step on droppings or bodily fluids from infected animals, potentially spreading the disease.
“Black vultures have been observed at these locations and these temporary closures are intended to help reduce HPAI spread,” read the news release from Constellation. “We will reopen these sites when it is prudent to do so.”
Most of the dead birds were found near the first guard shack entering the Fisherman’s Park parking lot on Shure’s Landing Road and near the Mason Dixon Trailhead, according to the release. The gravel parking area adjacent to the trail at Fisherman’s Park has also been closed. Officials haven’t found any dead birds next to the dam itself or the fishing wharf, Constellation said.
Federal laboratory testing confirmed the presence of H5N1 in samples taken from vultures found dead in the area on April 22, said Stacey Hofmann of the Delaware-Maryland HPAI Joint Information Center. All of the birds sampled tested positive, she added. Since then, more than 100 of the vultures have died from the disease, Hofmann said.
“We cannot confirm a total count as wild birds often get sick and die where people cannot see them,” Hofmann said in an email. “Black vultures are also known to fly long distances, which means infected vultures may die in other locations and transmit the virus to other birds.”
So far, the vultures are the only species affected in the area, Hofmann said. Officials are conducting surveillance and picking up dead vultures to prevent scavenging by other birds or wildlife, she added. Officials are recommending that the public avoid contact with birds, especially dead birds or any that are acting erratically. Birds can have the virus and show no signs of illness.