Birds Killing System
Telecom towers are killing nearly seven million birds every
year as they migrate from the US and Canada to Central and South America, says
a new study. According to the study, around 84,000 telecom towers, some of
which can rise nearly 2,000 feet into the sky, much higher than the Empire
State Building at 1,250 feet, dot the two countries. However, the birds are
killed not by running into the tower itself but the dozens of cables, known as
guy wires, that prop up the thin, freestanding structures, said study co-author
Travis Longcore, associate professor at the University of Southern California
Spatial Sciences Institute, US. "This is a tragedy that does not have to
be," added Longcore. The taller the tower the greater the threat, the
study found. The 1,000 or so towers above 900 feet accounted for only 1.6
percent of the total number of towers. Yet these skyscraper towers killed 70
percent of the birds, about 4.5 million a year, Longcore said, the journal the
Public Library of Science ONE reports.
During bad weather, the birds were pushed down by cloud
cover and flew at lower altitudes. The clouds also removed navigation cues,
such as stars, leaving only the blinking or static red lights of towers. The
blinking did not fool the birds, but towers with a static red light resulted in
more dead birds, according to a Southern California statement. "In the
presence of the solid red lights, the birds are unable to get out of their
spell," Longcore said. "They circle the tower and run into the big
cables holding it up." Longcore estimated that changing the steady-burning
lights on the 4,500 towers greater than 490 feet tall (about six percent of the
total) could reduce mortality about 45 percent, or around 2.5 million birds.
The study also recommended that businesses should share towers to reduce their
number and build more freestanding towers to reduce the need for guy wires. The
study did not include shorter towers that typically are used for transmission.
Source: CIOL World
No comments:
Post a Comment