March 25, 2008
Maybe a way to avert cell tower-bird collisions
As many as 50 million birds are killed annually in US cell-tower collisions. As more towers go up, builders and researchers eye solutions. The Christian Science Monitor reports.
"Hopes of solving the bird-strikes-tower problem are soaring.
"This has been an issue for 50 years," says Joelle Gehring, a biologist with the Michigan Natural Features Inventory in Lansing. "But in the past year and a half, for the first time, we have industry and conservation groups coming together to resolve it."
... The problem – and one partial solution for bird strikes – is less about the number of towers and more about the way they are illuminated at night, researchers say. All communications towers 200-feet or higher – and all towers near a flight path or airport – must be lighted according to Federal Aviation Administration (FAA) standards in order to warn pilots away, FCC rules mandate.
Such tower lighting is not a problem for birds in clear weather. But on stormy and foggy nights, when clouds are thickest, migrating flocks of birds tend to zero in on tower lights like moths to a flame.
... Today FAA regulations require both steady red lights and flashing red or flashing white ones. What Gehring found: Solid steady red lights were a big problem – creating an aura during cloudy weather that drew in birds.
When solid reds were removed, bird deaths fell 71 percent, according to Gehring's study, which has been peer-reviewed and accepted for publication later this year by the Journal of Ecological Applications.
Gehring's lighting discovery is "a major breakthrough," says Albert Manville, a senior wildlife biologist with US Fish and Wildlife Service in Arlington, Va. But that's hardly the end of the matter, he and others say. "
The Permanent Link to this page is: http://www.textually.org/textually/archives/2008/03/019505.htm
