07/16/2021

Songbirds Suffer Mystery Illness From The East Coast To The Midwest

12:12 minutes

a closeup of a small black bird on the ground with white crustiness around its eyes
This bird was found in the Washington, D.C. metro region with swollen eyes and crusty discharge, a sign observed on most birds affected by a mysterious illness. Credit: Leslie Frattaroli, NPS

Read an update on August 3, 2021 by 90.5 WESA about how cases of this mysterious bird disease decreasing in Pennsylvania.


The reports started in late May: Songbirds in Washington, D.C. and neighboring regions were being found dead, often with swollen and crusty eyes. In the days that followed, similar sightings came from many states, including Kentucky, Virginia, Pennsylvania, and New Jersey. Now, the symptoms have been seen as far west as Indiana—but wildlife experts still aren’t sure what’s causing the deaths. 

The illness has affected many species, including American robins, blue jays, common grackles, and European starlings. So far, investigators have found no signs of   salmonella and chlamydia; avian influenza virus; West Nile virus and other flaviviruses; Newcastle disease virus and other paramyxoviruses; herpesviruses and poxviruses; or Trichomonas parasites. But unfortunately, their tests have been inconclusive as to the actual cause. Experts are asking people in the affected areas to be on the lookout for birds with crusty eyes or behaving strangely—and in an effort at avian social distancing, they’re suggesting removing bird feeders until the cause of the ‘mortality event’ is known. 

Ira talks with Allisyn Gillet, state ornithologist for Indiana, and Lisa Murphy, a toxicologist and co-director of the Wildlife Futures Program at the University of Pennsylvania School of Veterinary Medicine, about what’s known so far about the illness, and about what steps investigators are taking to try to solve the medical mystery. 

If you find a bird exhibiting these symptoms, researchers encourage you to report it to the Wildlife Futures Program at the University of Pennsylvania.


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Segment Guests

Allisyn Gillet

Allisyn Gillet is Indiana State Ornithologist in the Indiana Department of Natural Resources in Bloomington, Indiana.

Lisa Murphy

Lisa Murphy is an associate professor of Toxicology & Co-director of the Wildlife Futures Program at the University of Pennsylvania School of Veterinary Medicine, and resident director of the Pennsylvania Animal Diagnostic Laboratory System in Kennett Square, Pennsylvania.

Segment Transcript

IRA FLATOW: This is Science Friday. I’m Ira Flatow. A bit later in the hour, a look at sweat– no, don’t change the dial. You’re going to like this. But first, it started back in late May. People in several mid-Atlantic states reported finding dead songbirds often with swollen, encrusted eyes. Now the illness has been spotted in states from Virginia to New Jersey and as far West as Indiana. And the cause is still a mystery. And while wildlife labs have been able to rule out some diseases such as salmonella, chlamydia, avian flu, West Nile– I could go on– songbird deaths are still a bafflement.

Joining me now to talk about the outbreak in songbirds and how you go about diagnosing an unknown wildlife disease are my guests, Allisyn Gillet, state ornithologist for the Indiana Department of Natural Resources, and Lisa Murphy, associate professor of toxicology, co-director of the Wildlife Futures Program, University of Pennsylvania School of Veterinary Medicine, and resident director of the Pennsylvania Animal Diagnostic Laboratory System. Welcome, both of you, to Science Friday.

ALLISYN GILLET: Thanks for having me.

LISA MURPHY: Yep, thanks for having us. This is great.

IRA FLATOW: Let me begin with you, Allisyn. Tell us the symptoms of this disease. What’s happening to these birds?

ALLISYN GILLET: Right. So like you had mentioned, they are experiencing these interesting symptoms of swelling and discharge from the eyes. They are also experiencing neurological symptoms, meaning that they tend to kind of move their heads in strange ways. Sometimes they look as if their heads are too heavy, as if their heads are swollen. So their heads will kind of dangle a little bit on the neck. They also experience things like tremors, disorientation, and perhaps even uncontrollable limbs.

IRA FLATOW: And when we say bird, I mean songbird, what do we mean by that? Do we know which birds get this and which don’t?

ALLISYN GILLET: Yes. So we know that blue jays, American robins, common grackles, and European starlings have been the ones that have been really affected by this disease, your typical urban bird. Think ones that you actually see at your feeders in the suburbs. But there are also other species that actually end up getting this disease, such as things like tufted titmouses, white-breasted nuthatches, and several species of woodpeckers that we’ve been seeing from public reports.

IRA FLATOW: The first reports were in places like Washington, DC, the surrounding areas. But Allisyn, you’re out in Indiana. Is this condition spreading from region to region? Or are people just getting better at recognizing it?

ALLISYN GILLET: That’s a great question. Honestly, I think it’s the latter. However, we don’t know enough about this disease to really pinpoint whether it is spreading further west. When I talk to my colleagues in, for example, Illinois or Iowa, they haven’t been seeing the disease like we have been seeing in our state, meaning they haven’t seen it to the extent that we’ve been seeing it. So mostly, a lot of our detections have been in urban areas, which totally makes sense because a lot of people are in these locations, as well as there are a lot of people feeding birds and watching birds in these locations.

And so I don’t want to particularly say that it’s perhaps spreading, because we don’t know whether it’s contagious or not. But I want to say that it’s perhaps people becoming more informed. And maybe it has been in our environment for some time before we really detected it knew about it.

IRA FLATOW: Lisa Murphy, you’re part of an effort to diagnose what this is, sort of this science sleuth here. How do you even start? I’m thinking of a movie where somebody sends you a dead bird and then it takes off from there.

LISA MURPHY: That’s right. And I’ll be honest. You’re not too far off. We kind of joke that when we get our mail deliveries here, we never know quite what we might open and find sometimes.

But I think a lot of time, the start may be these public reports that we’ve been talking about, is we hear that there is an issue. But then we have to actually start just taking those public reports and looking at them and sort of figuring out, what are they really telling us? And is there a difference between public reports versus can we get to drawing these connections and similarities and actually saying that they are suspect or verified cases of whatever is going on?

And I think what that really illustrates is the importance of just a history. Back to your movie analogy, what’s that bird’s back story before we met this bird? And you know, unfortunately, sometimes it’s difficult because we come into the story and the bird’s already deceased. So the person that’s reporting it hasn’t had an opportunity to observe them and see. So some of the things that Allisyn had mentioned, in terms of some of the signs and symptoms that we’re seeing in terms of them acting oddly– we’re missing that piece of the story if the animal’s just found dead.

But back to your story. OK, we now have the bird in the box. How do we do that? And I think it’s really, really important that we develop a process, that we are going through each of these cases very methodically just to make sure that we aren’t missing anything, that we’re approaching them all in the same way to sort of figure out all of the different things that may be going on.

I mean, I can speak most easily to toxicology since that’s my area of expertise, is we have an animal. There’s a concern. Could it have been something that poisoned it? We may or may not have those historical details that I mentioned. But as we get into the animal doing the examination, what are we finding looking at it externally? Are there any injuries? Are there any abnormalities?

And as we start to work through our different tests, what are we finding that can give us some clues or identify some paths that we want to follow? Is it just an eye problem? Or as we start to look at it more closely, maybe it emerges as a respiratory problem or a liver problem. And we start to build lists. And as we get more information, we can start to refine that list. We can begin to cross some things off.

IRA FLATOW: In my movie analogy, there’s always some magic tech angle. I mean, can’t you just DNA sequence everything and look for what doesn’t belong there?

ALLISYN GILLET: I love your movie analogy, but when you see it on movies or TV, it does. It seems like there’s some shiny blue light and about 30 seconds of catchy music, and they’ve got the name and address and the type of cologne that the perp wears. You know, you’re on it. If it were only that easy.

But again, back to looking at it methodically, like you said, whether it is doing PCR testing to look for viruses– in my laboratory, whether it’s toxicology testing to look for heavy metals such as lead or to look at pesticides or to look at drugs or what have you, is we go through a process, like I was saying, is based on what we know, this is where we’re going to go next. The point isn’t just to run a lot of tests. It’s actually to generate some results.

But as we take those results, we understand that people intend to act and make decisions based on those. So it’s really important to us if any results that we provide are accurate and timely, but they’re actionable. In fact, that’s really important to me as well, is it’s one thing to have that goal of finding out what it is, but the reason we want to find out what it is isn’t just to pat ourselves on the back and congratulate ourselves for figuring it out. But now it’s what do we do next to either try to stop it, at least mitigate it, hopefully to prevent it happening next time? That’s the end goal.

IRA FLATOW: Given that we don’t know what it is, we don’t know even if it spreads, Allisyn, I guess the best thing we can do is like we did during the Coronavirus pandemic, and that is to clean things up, right?

ALLISYN GILLET: Absolutely. I think it’s really good to be diligent about cleaning up things that provide some possibility for increasing the risk to these birds. So for example, we’ve been suggesting that people take down their feeders, mainly because just like we had experience with COVID, we wanted birds to be able to socially distance. And when it comes to feeders, feeders provide this opportunity for birds to come to pretty much a single point and to feed collectively, with not only just individuals of their own species, but also individuals of different species. And so it provides a lot of interaction between these birds.

And it also provides this potential for if it is a disease that might be carried on feeders, to pass from not only bird to bird but bird to feeder to bird. So we want people to clean up their feeders with 10% bleach solution and then air drying it completely so that there’s no potential for mold to grow. And then keeping it inside until you really start seeing the mortality event end– meaning birds are not being seen as sick anymore around your area. And then pretty much being informed about whether areas that are close to your cities are seeing these, because it might be in your area but you just might not be aware of it.

IRA FLATOW: And of course, if you see a dead bird, your actions should be what?

ALLISYN GILLET: Yes, so I recommend first, when you do see a dead bird, always protect yourself. Either wear disposable gloves or invert a plastic bag if you have the need to handle that bird– meaning taking it out of the environment– so that it won’t be able to possibly transmit the disease to you or any other wildlife or pets. And then looking at that bird and seeing, does it have the symptoms that we are describing, such as the gooey eyes, the crusty eyes, the swelling in the eyes, and I guess to see whether perhaps it might exhibit some sort of strange posture or something like that indicative of a neurological issue– and then after that, telling your state agency or your local wildlife agency that you found this bird with these symptoms.

We’ve been getting a lot of reports of dead birds in general. And birds– they live a hard life. Wildlife really experience a lot of different threats and risks in their environment. So they experience things like buildings and windows that they might not recognize as being very defined walls. And they end up colliding with these buildings and windows and then dying. Or they have predators in their environment like pet dogs, pet cats that also threaten them and cause them to, ultimately, die. And so we have been getting reports of just baseline mortality that is not necessarily being indicative of this particular songbird disease.

So if you do see the symptoms, please report it. But if you know that this bird definitely died from a car crash or a collision with a building or with a power line, you don’t need to report it.

IRA FLATOW: I’d like to thank both of you, Allisyn Gillet, the state ornithologist for the Indiana Department of Natural Resources, and Lisa Murphy, associate professor of toxicology, co-director of the Wildlife Futures Program, University of Pennsylvania School of Veterinary Medicine, resident director of the Pennsylvania Animal Diagnostic Laboratory System. Thank you both for taking time to be with us today.

ALLISYN GILLET: And thank you.

LISA MURPHY: Thank you.

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