Controlling the noise

Noise pollution disrupts wildlife ecosystems around the globe. For example, the disruption of bird communication has led to collisions into aircrafts and buildings, the destruction of crops, and the spread of disease. Professor John Swaddle from the College of William and Mary, joins Hari Sreenivasan to discuss this situation.


Human noise pollution disrupts wildlife ecosystems around the globe.

For example, the disruption of bird communication has led to collisions into aircraft and buildings, the destruction of crops, and the spread of disease.

Joining us to discuss the situation is Professor John Swaddle from the College of William & Mary.

Thanks for joining us.

So, what kind of impacts are we talking about when we say 'noise pollution'? It's something that -- Right now, I'm on a busy street in New York City, and there's a fire truck going by.

[ Siren wails ] That, to me, is noise pollution.

But what is the context in which you look at it when you're looking at entire ecosystems?

Sure. So, many people have studied the effects of noise on birds, and birds are particularly affected because they're very vocal.

They're always talking to each other.

And so if there's a bit of degradation of that information, it matters to birds.

And what we've been finding is that birds will leave areas that are too noisy for them.

And so that limits their habitat.

So, when they are moving into different areas, you can see that they've become a nuisance to farmers as they ravage through some of their crops, right?

Or even there was the kind of the Miracle on the Hudson, the plane landing.

That was caused from a bird strike, right?

Sure. Yes.

Many people, you know, like birds, and we want to preserve them, but we have to admit, in some cases, birds cause problems.

So, at farms, agricultural places, they can destroy the crops, and that causes billions of dollars of damage worldwide.

And in some countries, it's life-threatening, because people are reliant on those crops.

And then birds and aircraft are never a good combination -- for the aircraft or for the birds.

And bird strikes happen pretty much every single day across North America and are increasing, because the amount of air travel people are doing is increasing.

And we're also trying to preserve bird populations in different areas.

So, what we're trying to do now with noise pollution is try to use our understanding of how birds respond to noise to try and minimize that conflict between bird society and human society.

So, in particular, we're using speakers to try and put sound only where we want it that interferes with the way the birds communicate with each other, and they don't like it.

And they will go elsewhere.

So, for example, at the end of a runway, if you put in sound that then masks the way the birds can, say, listen out for predators, then the birds will choose to go elsewhere.

So, this is almost what you're describing is a sonic scarecrow 2.0, where instead of having something like an inanimate object just standing in a field, you're actually projecting sound into their ears, and they don't like it.

Exactly right.

So, we're projecting into a specific area where we don't want the birds to enter.

And because if they can't hear each other, they find that area very scary.

And then it's not something that they get used to.

Habituation has been the bugbear of all scarecrow industries for decades.

But in this situation, we're fundamentally changing the way the birds can get information from their environment.

It's like me giving you an option of, in a big city, at night, where you know there are issues, are you gonna walk down a darkly lit, narrow alleyway or a well-lit street?

And, essentially, we're doing that for birds, but in an acoustic sense.

And they choose the well-lit street, like most people would.

Is there any long-term damage to the birds if they're hearing these sounds or if the communication is disrupted?

Not that we've found so far, because the birds will leave and go elsewhere, and that's a key part of it.

As you manage it at a landscape level, you're moving birds off to another area.

So, for example, an airport manager who wants to reduce their risk -- they specifically don't want the birds around where the planes are taking off and landing, but on other parts of the airfield, it may be okay to push the birds into that area.

Well, what about birds striking into buildings?

Can you modify this tool in a way to keep them from -- I mean, it seems like their problem is that they're not looking and they don't see the building coming at them, 'cause they're probably looking down at the ground, right?

Exactly right.

So, the problem of bird striking buildings is slightly different.

When birds are flying, you might think that they're looking straight ahead of them, but they're actually not.

In lots of cases, they're looking at the ground, because that's what they've evolved to do is to use cues on the ground to navigate by.

Well, they might be foraging, too, as well.

And when a bird is in level flight, like this, its head is angled down, and in the vast majority of bird species, their eyes are more placed on the side of their skull, rather than right out in front, like us.

So that then means they're looking down and to the side.

And there are even some birds who actually have a blind spot right in front when they're in that flying position.

So that means they're really not looking where they're going.

It's not like someone texting while they're driving.

Their attention is not where it should be.

But what we've found is that if you play a really obvious, conspicuous, novel sound out in front of something that they could fly into, birds then start to pay more attention, and the risks of them colliding with that object decrease.

But what is this sound like?

I mean, is it just about playing loud music or is it about playing it at a frequency that birds get it?

Frequency is the important thing.

From what we've done so far, what we think is important is for it to be novel, something that they haven't experienced before or something they couldn't confuse with, say, just traffic noise or any other noises they would hear.

It's got to be something that grabs their attention, and so then they look up.

They slow down, have more chance of avoiding the collision.

Where have you been demonstrating it so far?

Where is it working?

So far, we've demonstrated it in captivity with trained birds that are going up and down a long hallway.

The next step we need to take is to go, then, put this in front of a real structure in the environment with free-living, wild birds.

That will be the real test of whether this idea works.

And how long until that happens?

Oh, that depends on funding.

So, hopefully, hopefully, this fall and in the spring.

Bird migration is a big time when birds are moving across the continent, and so that's when the risk of them flying into objects, like tall buildings, wind turbines, cellphone towers, increases.

So we're hoping to work with either the fall or the spring migration this year.

All right.

John Swaddle, professor of biology at the College of William & Mary, thanks so much.

You're welcome. Thank you.