Smithsonian's National Zoo: Mysterious Bird Deaths In The Mid-Atlantic Region

Press release from Smithsonian's National Zoo:

June 28, 2021

This update was written by Smithsonian Conservation Biology Institute ornithologist Brian Evans

In late April, birds in the D.C. region began to turn up sick or dying. Scientists are trying to figure out why. Learn more in this Q&A with Smithsonian Conservation Biology Institute ornithologist Brian Evans

What is happening to these birds?

This is something we as scientists refer to as a mortality event — when a large number of animals die in a relatively short period of time due to what appears to be a common cause. We’re seeing birds exhibit distressing symptoms, including problems with their eyes and possibly their nervous systems. Many birds have been found blind and or with crusty eyes. They often appear on the ground, confused, with shaky heads, and are sometimes lethargic or unresponsive.

What species of birds are affected?

We’re seeing this across several species of your typical backyard birds: mostly blue jays, common grackles, European starlings, American robins; but also Carolina wrens, gray catbirds, house sparrows, northern cardinals and northern flickers.

So far, it’s been mostly juveniles, but we’re also seeing it in adult birds.

Where is this happening?

Right now, it seems that birds in the mid-Atlantic region are hardest hit. But similar cases have been reported across the country, including Florida, Ohio and other states.

When did this start?

To the best of our knowledge, birds mysteriously started falling ill and dying in April 2021. It seems to have peaked in early June in the mid-Atlantic. We see some indications that the bird deaths are now declining — or at least fewer birds are being brought into local wildlife rehabilitation centers. But it’s still too early to really tell.

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 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 the cicadas were underground.

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

How can I help?

For now, per U.S. Geological Survey (USGS) guidance we’re asking everyone to take down and clean their birdfeeders and birdbaths in case these deaths are linked to a contagious disease.

Be a citizen scientist. If you find a sick or dying bird, we need you to report it. We’ve set up this online form with a few questions so that we can collect more data on live and dead birds. If you’ve found a live bird, please complete the form. After, you’ll be directed to your local wildlife rehabilitation center for more instructions.

The information you submit — date, location, bird age, species (if you know it), and a photo— will help us understand the scope of this event.

SUBMIT A BIRD REPORT

This press release was produced by Smithsonian's National Zoo. The views expressed here are the author’s own.