Air Date: Week of December 11, 1998
Living on Earth's Daniel Grossman investigates the link between migratory birds and radio towers, and how they may impact birds' flight and health.
CURWOOD: Each fall, billions of song birds migrate to warmer climes in remarkable feats of flight. Ornithologists don't really know how birds like the tiny black pole warbler, which weighs less than an ounce, manage to fly thousands of miles from Canada to the Andes in South America. But they do know that the ranks of the warbler, and many other species of migratory song birds, are in serious decline. Loss of habitat, pesticide use, even house cats are all believed responsible for the song birds' demise. And as Living on Earth's Daniel Grossman reports, researchers are now identifying another looming threat.
(A truck runs noisily)
EVANS: We're about less than a mile from the towers, and it's just amazing how high these reach up into the sky.
GROSSMAN: Bill Evans maneuvers a beat-up pickup truck down a bumpy road to a twin set of steel TV towers. The Cornell University ornithologist is worried that towers like these are a threat to song birds. Tonight he's brought me here just south of Syracuse, New York, to show me why. He pulls up to the nearest tower.
EVANS: You can see how this -- this tall structure goes up a thousand feet. And you can see the guy wires lit.
GROSSMAN: Although the latticework tower itself is invisible in the darkness, its looming silhouette is marked by blinking aircraft warning beacons climbing its spine.
EVANS: Let's see, how many sets? One, two, three, four, five, six tiers of red lights.
GROSSMAN: Researchers have discovered that on overcast fall nights, song birds sometimes hit towers like this one and die by the hundreds, and even thousands. Bill Evans says these warning lights cause the trouble. Most song birds migrate at night to avoid predators and use stars to navigate. But on cloudy evenings, he says, the migrants must rely on other cues for guidance.
EVANS: So they're bombing along at night, and they see lights.
GROSSMAN: And in the fog these lights create a brilliant, glowing ball. Bill Evans says the birds appear confused and think it's day time.
EVANS: So they tend to stay in that lighted area, and as more and more birds keep migrating by and getting into that area, you get a little tornado of birds, almost. And we think that the birds collide with one another, they collide with the tower structure, especially the guy wires, which aren't lit as well as the tower structure.
GROSSMAN: The threat of the metal spires is emerging as a source of conflict between bird lovers and the communications industry, which by and large discounts these events as freak accidents. Bill Evans says large kills are unusual, but common enough to pose a worrisome threat. And he's carrying this message to government agencies and ornithological societies with zeal. He says his crusade began by chance 2 years ago on a Nebraska hilltop. He was recording bird calls one foggy night at the base of a tall communications tower.
EVANS: On a couple occasions I heard this collision, which sounded like it was with the tower structure. And then on one occasion I even heard a thud on the ground, which must have been right near the microphone.
GROSSMAN: Mr. Evans kept the recording he made that night, and he plays me the scratchy tape.
EVANS: Okay, here's this staticky noise, insects. Right here, there's that little shhh of the wing sound and the collision... and right there was the thud on the ground.
It really wasn't until I heard these recordings of the birds hitting the tower that it really hit me in my heart. That was sort of a despairing moment and I basically had to divert some of my attention to this other issue.
GROSSMAN: Mr. Evans is the most vocal person calling attention to the threat of towers, but so far he's relying on the work of others to make his case. And one of the most important studies is being done by a researcher in Buffalo, New York.
GROSSMAN: Arthur Clark walks briskly to his fourth floor office in Buffalo's Museum of Science.
(Footfalls continue; keys jingle)
CLARK: This is the vertebrate department.
GROSSMAN: Mr. Clark is the curator of the museum's bird collection. For more than 30 years he's visited 3 tall towers near here after overcast fall nights. He collects the fallen birds he's found and keeps them in a giant walk-in freezer.
This is your freezer here?
CLARK: Yes. This is our walk-in freezer. (A door slides.) You can see it says tower kill, this is TV tower kill. These are tower kills from '71, '80, '82. (Fans run.) If you want, we can take a box out and --
GROSSMAN: So how many birds do you have here?
CLARK: Well, a good percentage of the 20,000 that we picked up over the 32 years.
GROSSMAN: It's too cold to stay in the freezer for long. Mr. Clark grabs a box and hustles for the exit. This box once held stationery. Now it's neatly packed with 96 colorful corpses.
CLARK: Here are some rose-breasts grosbeaks. Some Swainson's thrushes. Some palm warblers. And these are black-throated blue warblers, here's a male black-throated blue, isn't that a beautiful bird?
GROSSMAN: Mr. Clark has collected more than 110 species of birds. He keep a tally sheet showing how many die each night. On 3 occasions, the total has topped 1,000.
CLARK: We were not able to drive up to the buildings. There were so many birds lying around on the parking lot. In fact, the transmitter operators that drove there wound up flattening a number of birds. We had to sort of scrape them off just to identify them for our tally.
GROSSMAN: And these towers are not the only ones of concern. One researcher collected more than 120,000 birds in a 37-year period at a tower in Eau Claire, Wisconsin. In January 1998, as many as 10,000 sparrow-like Lapland larkspurs died in a single night after colliding with a tower in Kansas. And there are about 40,000 other communications towers tall enough to require warning beacons. Some researchers say the nationwide death toll could exceed 4 million song birds each year. That's a small fraction of the total population, but many researchers worry about adding stress to these birds, since scores of song bird species are already in decline.
MANVILLE: The red flags are going up. These are fairly significant impacts.
GROSSMAN: Al Manville is a top official at the US Fish and Wildlife Service, the Federal agency responsible for the health of migratory birds. He says the problem is America's mania for wireless communications. And things are getting worse, not better.
MANVILLE: The new digital PCS phone system is going to go online. It may require, within the next 10 or 15 years, over 100,000 towers nationwide. And then the biggies are these digital TV towers and the estimates I have are, there are going to be, over the next 10 years or so, at least 1,000 new digital television towers put online of a fifth of a mile or so in height. These are the behemoths, the monsters.
GROSSMAN: Some of these huge towers are already underway. And they're proving controversial.
(A gavel strikes.)
MAN: This is a regular meeting of the planning board of the town of ...
GROSSMAN: The planning board of Baldwin, Maine, is called to order. On the docket is a proposal by WMTW to build a 1,700-foot digital tower, 200 feet taller than the Empire State Building. A number of Baldwin residents oppose the plan, including Rebecca Willman.
WILLMAN: This is the worst of all possible circumstances. It's 40 miles from the coast of Maine. It's a foggy area. It's the North Atlantic migratory route. It's an enormous tower on a bit hill. There's no question that this tower is going to kill birds, and that is something we cAnneot live with.
GROSSMAN: This is the board's fourth in a tumultuous series of meetings on the tower. Many objections to the project have been raised, but so far the plAnneing board has been unimpressed. A vote is called. The decision is unanimous.
MAN: The conditional use permit for WMTW Holding Company for a communications tower is approved.
GROSSMAN: Previously, the station's general manager, David Kaufman, had refused to speak to me. I catch up with him as the meeting breaks up.
GROSSMAN: Can I ask you a couple questions, Mr. Kaufman?
GROSSMAN: What about this issue about birds? Is this a concern?
KAUFMAN: I think the record speaks for itself.
GROSSMAN: Which is what?
KAUFMAN: I think it stated that it does not appear to be a significant problem.
GROSSMAN: Executives at the National Association of Broadcasters, the trade association for TV and radio, are also downplaying the threat of new towers. The group turned down a request for a taped interview, although one attorney there said the number of birds affected was too small to be of concern. Other communications officials are not so dismissive.
SHARK: I think that we're open to a solution, as long as it doesn't stand in the way of the mandate that we have, you know, to build out systems and to serve customers.
GROSSMAN: Allen Shark is president of the American Mobile Telecommunications Association, which represents radio phone customers like taxicab companies. He says technology is causing the problem and could also be the solution.
SHARK: My hope would be that somebody listening to this program, somebody who has read about this, somebody who's becoming aware of this is going to say, I wonder if this is a business opportunity for me? I wonder if I could experiment with a tower in some location in some simulated area, where I could come up with some kind of warning signal, warning device that might work toward thwarting birds, you know, hitting my towers or guy lines.
GROSSMAN: But no one is stepping up to the plate yet. Meanwhile, thousands of new towers are going up each year. And that's making the journey for winged migrants harder than ever. For Living on Earth, I'm Daniel Grossman.
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