Mystery Strikes Region's Birds - Bay Weekly
Disease that blinded, killed Pa. songbirds vanishes as mysteriously as it arrived
Mysterious disease affecting songbirds in Pennsylvania - Farm and Dairy
Mysterious disease blinding birds in Ohio, leaving them unable to fly
Carolina parakeet - Wikipedia
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American Bird Conservancy - Some states, including Pennsylvania, Maryland, and Virginia, are reporting a decrease in cases of the mysterious bird disease that's been monitored this spring, and officials there now say
Big Chicken': The medical mystery that traced back to slaughterhouse workers
Reports Of Mysterious Bird Disease Decreasing In Pennsylvania