MS. REBECCA SHEIR
We turn now from the wellbeing of our city's schools to the wellbeing of our city's birds. Turns out the dull roar of city life is affecting how birds sing their songs. Environment reporter, Sabri Ben-Achour, brings us the latest on what researchers are finding in D.C. and Maryland.
MR. SABRI BEN-ACHOUR
Have you ever been in a bar where it was just too loud to talk to anybody? Whew, that's better. I said, have you ever been in a bar where it was too just loud to hit on anybody?
UNIDENTIFIED MALE 1
All the time.
UNIDENTIFIED MALE 2
UNIDENTIFIED MALE 3
There's times when you just, you can't.
UNIDENTIFIED MALE 4
I don't go to loud places for that reason.
That's Aharon Conerly, Mikey Maliksi, Lance Bullerdick and Vladimir Stanisic, all at various bars along 18th Street and Adams Morgan.
I mean, it's pointless.
Man, that's terrible. But do you know who feels their pain? Birds. Seriously, birds.
DR. PETER MARRA
We know that birds are adjusting.
Peter Marra is a conservation scientist at the Smithsonian Conservation Biology Institute. He says a big part of being a bird is singing, it's often to hit on other birds and it's hard to do that because it is really, really noisy in a city.
The sounds of trucks.
Traffic in general.
It's like living in a bar.
Urban noise, those sounds compete with low-frequency sounds.
So birds with lower songs have to sing differently.
Those low-pitched sounds decline in five out of six species that we studied in urban areas. So birds have sort of tried to change their songs to higher frequency or mid-frequency songs.
Can you show me a few examples?
Sure. Sure. So first I'll play a Carolina Wren in a rural area so where there's very low ambient noise.
And this is a recording of a Carolina Wren at an urban site where there's a lot of other background noise.
What you can tell is that the pitch of a song of the Carolina Wren in the urban site, it's lost a lot of its low-frequency sound.
Here it is again.
It may be hard for us to hear the distinction, but we aren't birds. Birds probably can't much tell the difference between a lame human pickup line and a really good one either. Singing higher probably won't work for humans.
But singing over the traffic isn't the only problem for birds. It turns out that big buildings distort songs too, especially the highest pitches.
Their songs are compromised by the buildings themselves, which absorb songs and refract songs and songs and sounds bounce off those buildings.
So higher pitch songs like this House Wren's.
Echo in weird ways and get garbled.
So high pitch birds sing lower. That could work for humans.
Several of the species Marra and his colleagues looked at narrowed the range of their songs, cutting out the high parts and the low parts. So what does all this mean? Marra says we don't know yet.
You have animals who are adjusting their communication, they're changing the way they speak, their accents might be changing. But to what degree is this changing the number of young they have or how well they survive?
Could be that noise is a reason some birds stay out of cities.
One of the species that don't occur here anymore, that have already been impacted, when they're absent it's a difficult thing to really understand.
Maybe they'll change their language.
That would be an evolutionary question.
Or maybe it'll change what city birds can hear.
Right. So it may be that the bird, the cardinal or the Carolina Wren, that's also receiving that signal, may be modifying the range at which it receives things.
Or maybe it means absolutely none of these things. But there is a point to thinking about it.
Urban environment pose lots of challenges for animals, challenges we're really just starting now to quantify. When you think about an animal like a bird, it's not just about where they nest. It's not just about where they eat. It's also about how well they can communicate in this urban, concrete jungle.
An urban jungle where a good pickup line is key not just to a fun night out, but to the survival of the species. I'm Sabri Ben-Achour.
To hear more bird sounds and to learn how you can get involved with bird research in your own backyard, check out our website, metroconnection.org.
After the break, trains, planes, automobiles and claustrophobia. What it's like to travel when confined spaces give you the willies.
MS. KATHLEEN CAGGIANO
I felt my throat closing in and I couldn't make it. I went a couple stops and then I had to get out.
It's just ahead on "Metro Connection," here on WAMU 88.5.
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