Mysterious Illness Killing Songbirds in 6 States

UPDATE 13 Aug 2021: The PA Game Commission has announced an end to bird feeding restrictions. The illness has faded away on its own.

27 June 2021

A mysterious illness, first recorded in the DC area in mid April 2021, is blinding and killing songbirds in six states. Scientists at many labs are investigating but there are still no answers. No one knows what’s causing it.

Symptoms include crusted-over eyes, blindness, seizures, loss of balance, and death within a day. Indiana DNR reports that the illness mostly affects medium-sized songbirds: blue jays, American robins (photo at top), common grackles (photo below), starlings, northern cardinals, and brown-headed cowbirds.

So far the disease has been reported in the DC area including Virginia, Maryland, and the eastern panhandle of WV, and in central and southwestern Ohio, parts of Indiana, and north-central Kentucky. My attempt to map the disease centers, below, is missing many incidents outside the red dots. UPDATE, 2 July 2021: The illness is also in PA and Delaware, now in 8 states, shown below.

Inadequate map of bird death hotspots as of 1 July 2021 (markup by Kate St. John)

For instance, Indiana DNR lists the counties where the illness has occurred. My map does not included these scattered locations. (In other words, don’t rely on my map.)

Counties in Indiana reporting mysterious bird disease as of 27 June 2021

Residents in affected areas are asked to take their feeders down so that birds do not congregate. There are good reasons to do so …

Megan Kirchgessner, a veterinarian with Virginia’s Department of Wildlife Resources, said “From a veterinary perspective, especially in the springtime when food is abundant, there’s no reason for those feeders to be out,” she said. “And to be perfectly honest, especially in a situation like this, they can do more harm than good.”

Washington Post, Public urged to stop feeding birds, 14 June 2021

Though no one knows what’s causing the illness, avian flu and West Nile virus have been ruled out.

Some, including an ornithologist at the Smithsonian Migratory Bird Center, have speculated the illness is related to the Brood X cicada emergence (yellow on the map below), that the birds are consuming pesticide-laden or fungus-laden cicadas. If so, the disease will disappear in July when the cicadas do and will not return for 17 years.

Active periodical cicada broods in U.S. (2013 map from USGS via Wikimedia Commons)

The cicada connection occurred to me too. The disease map as of 1 July 2021, after PA and Delaware were added, more closely matches the Brood X map.

For now we wait for more information and pray the illness doesn’t spread.

(embedded photos from Facebook and Twitter, maps from Wikimedia Commons. Click on the captions to see the originals)

14 thoughts on “Mysterious Illness Killing Songbirds in 6 States

    1. At this time of year it doesn’t hurt to take down the feeders (even outside disease zones) because there is so much insect and fruit food available for the birds. The latest recommendation is to take away water and hummingbird feeders as well. Also, it’s important to regularly clean feeders and baths with a 10% bleach solution.

  1. Apparently, there have been some reports of suspected cases in Central PA. I hope scientists figure this out soon.

  2. I’ve noticed so few hummingbird sightings this year in Pittsburgh and so have others in the area.
    I even learned from a relative in Oklahoma that they too have seen less of them this year.
    Do you know if there is a problem for Hummingbirds too?

    1. Sue, as of 28 June in the Mysterious Illness zones people were told to take down their feeders but were allowed to keep up their hummingbird feeders. I take this to mean that the illness is not affecting hummingbirds.

  3. I’m sure you heard about the possible cicada bug connection?


    What’s killing these birds?
    At this time, the cause remains entirely a mystery, and we’re still collecting data and exploring a number of potential causes.

    When there’s not an obvious cause for something like this, we typically look for ways the environment may have changed. And what’s different this year is the cicadas.

    Could these bird deaths be linked to the 17-year Brood X cicada emergence? There are a few different ways the cicadas could have caused mass bird death.

    Many songbirds in our region ate a lot of cicadas in May and June. When birds eat a lot of cicadas, they are essentially exposed to high levels of whatever is in the cicadas. So, even low levels of toxins in the cicadas are magnified when a bird eats hundreds (or even thousands) of them. These toxins can come from fungus, pesticides, or anything else in the environment over the span of the past 17 years that the cicadas were underground.

    If these bird deaths are not linked in any way to the cicadas, then we’re going to have to dig a lot deeper. But because this didn’t happen last year or the year before, the cicadas are a good place to start looking for answers.

    1. Yes, I included the cicada connection in both articles — this one and my article on 28 June.
      Thank you for the Smithsonian link.

    2. I researched for only FIVE minutes, and articles say Cholinesterase inhibiting pesticides can cause ALL these symoptoms in birds.. Did they test for them? Not to mention glyphosate and friends have been killing them off for years. The world is gong to hell in a bucket.

  4. So if 17 years worth of being caked with pesticides and fungus were causing the current die off…wouldn’t there have been a similar record in 2019 (IN ALSO PENNSYLVANIA) when that 17 year brood arrived??? Or did those particular Pa counties take protective measures smh.

    1. Peter, if it has anything to do with cicadas my hunch (based on my own guess, not on facts, not on empirical evidence) is that it’s caused by an over-the-counter pesticide/poison used this year on the cicadas & the birds ate those cicadas. … but we still don’t know.

  5. Does anyone know if the dying birds are being found only in areas where they had access to bird feeders? IOW, are birds in the wilderness areas dying from this, too? I keep wondering if a batch of pesticide-contaminated bird seed was shipped to these various locations. Have local authorities asked the public for samples of the food put in feeders at houses with dead birds?

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