Monday, September 04, 2006

More birds falling victim to communications towers

With the rapid spread of towers for cellular telephones, pagers, digital television and other high-tech communications, the crowded skies are becoming more dangerous for their original users: birds.

Biologists fear that each year millions of U.S. migratory birds become disoriented by lights on communications towers and crash -- into the towers, their supporting cables, the ground or even each other -- and die. The experts call it getting "whacked."

For the first time, ornithologists, government regulators and communications industry officials will convene in a special workshop in Ithaca, N.Y., on Wednesday to figure out how bad the whacking problem is and how it might be stopped.

"This is a real problem, and we take it very seriously," said Al Manville, a wildlife biologist for the U.S. Fish and Wildlife Service who is coordinating the conference. "It's becoming a major threat."

In the 1970s, a study figured that towers killed 1.4 million birds each year. Now Evans puts the number closer to 4 million. No comprehensive national study has been done.

More birds are dying now because there are more towers to whack, Manville said. Experts estimate that there are 80,000 towers in the United States, with about 5,000 new ones built each year.

That's what scares ornithologists.

"With the unprecedented growth of the towers in the communications industry . . . it's kind of a race for what can we do to make these towers bird-friendly before more towers go up and whack more of these birds," Manville said.

It's a race that the birds -- beautiful songbirds such as warblers, tanagers and orioles -- are losing because they are already under attack from loss of habitat, pesticides and even pet cats, said Gerald Winegrad, vice president of the American Bird Conservancy.

"You couldn't have devised a system that could be more destructive to the most watched species in the country," Winegrad said. "They're being destroyed by all these discrete methods. The songbirds are overall in a serious decline."

Birds whack into towers during spring or fall migration periods. When it is overcast, the light from the communications towers reflects off the clouds at night. The birds get confused. They shut off their normal nighttime navigation system and fly toward the light.

"They run into the tower, they run into the wire, they run into the ground, they get whacked," Manville said.

But while bird scientists are convinced the towers are causing major mischief, they are a long way from being able to do anything about it.

Officials at the Federal Communications Commission, which regulates the companies that use and build the towers, and the Federal Aviation Administration, which requires lights on towers more than 200 feet tall, say they want to work with bird experts. But first they say they need more evidence.

"We're in the very early stages, and clearly there needs to be more work done to actually determine if a problem exists and, if a problem does exist, how severe it is," said Sheldon Moss, director of government relations at the Personal Communications Industry Association, the largest wireless trade group.

There are well-documented individual incidents of bird slaughter caused by towers, such as the January 1998 kill of about 10,000 birds in western Kansas in one night. Other towers have had thousands of birds drop around them in a single night.

A few towers have been studied for years. For example, retired Chippewa Falls physician and amateur birder Charles Kemper has collected more than 120,000 bird carcasses around a single television tower since the mid-1950s, including 12,000 in one night.

Arthur Clark, associate curator of vertebrate zoology at the Buffalo Museum of Science, has been picking up birds killed by towers since 1967, and he has found fewer birds killed around the three towers he has studied. But that may just be because there are fewer birds or the birds hit other towers.

But even though fewer birds are hitting his towers, there are more towers. So, Clark said, "you are increasing the odds of taking out more birds if you're putting up tens of thousands of 200-foot towers."

Evans proposes using acoustic devices to shut off the lights when birds approach or turning off the lights on the towers permanently and putting new tower-detecting devices on all planes so they don't have to rely on a visual beacon.


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