Mysterious disease affecting songbirds in Pennsylvania

blue jay

UNIVERSITY PARK, Pa. — Pennsylvania residents may see dead and dying songbirds exhibiting strange symptoms, warns a Penn State Extension wildlife specialist who is monitoring the spread of a mysterious disease in the eastern United States.

“As many residents have heard, there have been recent reports of sick and dying songbirds around the Northeast,” said Margaret Brittingham, professor of wildlife resources in Penn State’s College of Agricultural Sciences. “The affected birds have crusty eyes and neurological symptoms that may include seizures, difficulty standing and head shaking.” 

In late May, bird mortalities were reported in the Washington, D.C., area, Maryland, Virginia, West Virginia and Kentucky, Brittingham noted. In June, there were additional reports from Delaware, New Jersey, Pennsylvania, Ohio and Indiana. In Pennsylvania, most of the cases have occurred in the southeast region of the state. 

“We are tracking this emerging issue and will provide new information as it becomes available,” she said. The primary species reported to be affected are blue jays, common grackles, American robins, northern cardinals and European starlings. Many of the reports are of young birds that recently have left the nest, but adults also are affected. 


In Pennsylvania, there have been 70 reports of birds showing the described neurological symptoms and crusty eyes. These birds are not restricted to a specific family or group of birds. Those affected include 11 species from 10 bird families. 

“Currently, we know more about what is not causing these symptoms and deaths than what is causing them,” Brittingham said. “A number of diagnostic labs across the country are working on unraveling this mystery. In Pennsylvania, the Wildlife Futures Program at the University of Pennsylvania Veterinary School is working in conjunction with the Pennsylvania Game Commission to test birds for different pathogens and toxins.” 

At a national level, Brittingham explained, scientists at the U.S. Geological Survey’s Wildlife Health Lab are tracking results from across the country and have reported that they have not detected Salmonella or Chlamydia bacteria; avian influenza virus, West Nile virus or other flaviviruses; Newcastle disease virus or other paramyxoviruses, herpesviruses or poxviruses; or Trichomonas parasites in birds tested to date. Toxicology tests are ongoing. 

One speculated cause circulating in the popular media is that the illness is related indirectly to the emergence of brood X periodical cicadas because of the timing and geographic correlation between the emergence and bird deaths, Brittingham pointed out, “but at this time, it is all speculation, and we need to wait for results from the diagnostic labs before we can fully understand the issue.” 


Brittingham urges residents to follow the Pennsylvania Game Commission’s recommendations. Report any birds that you find dead from apparent illness using the Bird Mortality Report Form online at Take birdfeeders down to increase “social distancing” in birds to reduce the risk of disease spread. 

Wash feeders and birdbaths and soak them in a 10% bleach solution before putting them back out after this problem is over. Wear disposable gloves to collect any dead birds and place the birds and gloves in plastic bags for disposal in the trash. Keep pets away from sick or dead birds. Wash your hands with soap and water after handling birds or feeders. 

Residents should consider other ways to help birds, Brittingham suggested, adding that birds rely on natural habitats such as forests, fields, wetlands and woodland edges. Backyards, community parks and other open spaces can provide critical habitat, especially in urban and suburban areas. 

Information on landscaping for wildlife and related topics can be found at

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  1. is this disease affecting hummingbirds. I took my h-bird feeder down a month ago and they are still “knocking on my window” for food. I am in Monroe County PA, the Cresco area. Please let me know as the temptation to start feeding them again is almost overpowering.

    • Although no reports have been released that state hummingbirds are impacted by the illness affecting songbirds, some state wildlife agencies have advised residents in states with incidences of the illness to remove hummingbird feeders, too, to prevent the spread of the illness.


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