Bird 'Mortality Event' In PA Continues To Mystify Researchers

PENNSYLVANIA — As reports of a mystery disease afflicting songbirds come in from 62 of Pennsylvania’s 67 counties, the state has issued an alert and dubbed the phenomenon a “songbird mortality event.”

While its cause remains unknown, authorities estimate that around 500 reported cases in Pennsylvania thus far can be linked to the ailment. The Pennsylvania Game Commission recommends that residents take down bird baths and bird feeders to minimize spread in areas where birds may congregate.

The birds most likely to be afflicted are of fledgling age — recently having left the nest — and include common grackles, blue jays, European starlings, and American robins. Those afflicted are presenting with eye swelling and crusty discharge, along with neurological symptoms.

Researchers have ruled out pathogens including salmonella, chlamydia, avian influenza virus, West Nile virus, Newcastle disease virus, herpesviruses, poxviruses, and Trichomonas parasites. Results from multiple diagnostic tests at New Bolton Center and Penn State’s Animal Diagnostic Laboratory have not yet come back.

“At this early stage, we do not know what is causing the illness. Diagnostic tests are pending,” Penn Vet Communications Director Martin Hackett told NBC10. “Investigations of newly emerging wildlife diseases are always a challenge due to all the unknowns — and it takes time.”

Residents can report suspected occurrences to the Wildlife Futures Program. Pennsylvania officials also advise disposing of dead birds with household trash to prevent disease transmission to other birds and wildlife.

The disease has also been reported in New Jersey, Tennessee, Kentucky, Virginia, West Virginia, Delaware, Maryland, Indiana, Ohio, and Florida.