Collisions With Communications Towers
know our TV and cell phone habits are contributing to the deaths of
millions of migratory birds a year? The birds collide with the communications
towers transmitting our cell phone and TV airwaves and with the cables
that anchor the towers. Those towers become sky-high death traps for
birds, who then drop in grass, streets, parks, and fields, and on rooftops.
Using numbers from several long-term studies, conservation groups and
government biologists estimate that communications towers kill from
4 to 50 million birds a year. They endanger or threaten at least 50
The number of communications towers in the United States is unknown. It was
estimated at 100,000 in 2002. The only registered towers are those 200 feet
or taller; these are required by the Federal Aviation Administration to have
safety lighting. Thousands of shorter towers, controlled only by local zoning,
have popped up with the boom of cell phones and pagers. Thousands more towers
of all sizes are being built each year--a result of more cellular telephone
service and digital television networks.
of new towers is deadly news for migratory birds. The tower-bird collisions
occur (1) during spring and fall migrations, and (2) at night, when
songbirds travel to avoid the heat and daytime predators. For birds,
such as whooping cranes, that fly during the day but cannot see the
power lines, the towers and lines are the Number One migration danger.
Working on Solutions
Many of these nighttime travelers can cross oceans and navigate mountain ranges.
What makes them crash into the blinking, lighted towers? Scientists aren't
certain. The worst kills happen when a flock, which might number half a million,
flaps toward a lighted tower. Something about the lights attracts the birds.
Red beacons seem to draw birds more than other lights do, although studies
suggest that red wavelengths may disrupt the birds' ability to navigate using
the stars or the earth's magnetic fields. The weather may play a role, since
large kills almost always occur on cloudy or foggy nights. Fog, mist, or storms
increase the odds of trouble. Unlike larger birds, which can climb above the
clouds, smaller migrants sometimes try swooping underneath, right into the
path of towers.
The big question is, What can be done to keep birds away from the sky-high
death traps? A committee was formed to research tower kills. The Communication
Tower Working Group is made of about 50 federal officials, conservationists,
researchers and people from private businesses. But research takes money, and
funds are short. The fast-moving communications industry and some government
leaders don't see the studies as top priority because more birds are killed
by roaming cats, speeding cars, pesticides and tall, shiny office buildings
than by tower kills. Most people feel that habitat loss everywhere is the biggest
threat to birds. Still, tower kills are a big contributor to bird deaths, and
a cause we can do something about. Friends of the Earth and the Forest Conservation
Council are two environmental groups that say the Federal Communicatons Commisision
(FCC), which regulates tower construction, should be the lead voice. Should
tower-building be stopped until a full study is done to show how the towers
affect bird populations? That's one idea.
cut down the kills, the United States Fish and Wildlife Service has
created some guidelines for
the tower industry. Following the guidelines will save birds but mean
higher costs for an industry that is racing to expand. There are many
groups with interests at stake, and there are no easy solutions.
YOU Can Do
and speak out. If towers are proposed for your community, make your
voice heard. Ask the people in charge of the towers if they are voluntarily
following the guidelines
for bird-friendly tower construction.
more and pass the word. See these resources, and look for more:
Towers," by David Malakoff. Audubon Magazine, September-October
2001, pp. 78-83.
On this Web site, you'll see a map with dots showing the height and
placement of towers in your state. This site also has links to articles
and the U.S. Fish and Wildlife Service's guidelines.
This! Activities and Discussion Questions
and discuss the 12 U.S. Fish and Wildlife Guidelines for bird-friendly
tower construction. Print a copy of the this
page and make an overhead transparency or pass out copies to
small groups. Ask, Do the guidelines seem fair and effective?
What questions do you have? How might we find answers?
scale models or draw illustrations of bird-friendly towers. Display
them in your community along with posters to educate the public about
this threat to our already decreasing populations of migratory birds.
or discuss this question: Why should we care if birds die at
TV towers? Share your reasoning. (Did you remember that wild
birds are important in ecosystems as plant pollinators, insect eaters,
and seed spreaders? Did you think about the beauty added to our lives
by bird songs, antics, and colors?)
Science Education Standards
in environments can be natural or influenced by humans. Some changes
are good, some are bad, and some are neither.