Wind Turbines and
Birds
(This column was first published in
the May 9, 2004 issue of The Buffalo Sunday News.)
An important debate is being waged between the
proponents of wind turbines and naturalists concerned about birds that may by
killed by those windmills.
Both
sides agree that, like solar power, wind power is an important alternative to
fossil fuel-burning generators that pollute the atmosphere and lead to health
problems. This issue is especially timely because today 94 new coal-fired power
plants are planned in 36 states. Erie and Chautauqua Counties have already been
cited for sub-standard air quality and these new plants, many of them upwind
from us in the Midwest, would add still more mercury and greenhouse gasses to
our atmosphere.
Beyond
their agreement about the need for the benign energy production of wind
turbines, however, disagreements arise and we could be headed for gridlock.
Perhaps the best example of this is to be seen in the headline over an
otherwise reasonable newspaper statement by Elmer Marien, president of the
Buffalo Audubon Society. It reads: "Keep Wind Turbines out of Migration
Routes". Since birds migrate across broad fronts that cover all of North
America, that order could effectively end wind power.
Indeed
wind turbines can kill birds.
Today's
windmills are giants. You can see ten in action in the Wyoming County Town of
Wethersfield. Each 213-foot turbine tower there supports three 77-foot blades.
Thus they reach a height of about 290 feet, still, however, well below the usual
flight path of both day and night-flying bird migrants. Their blades turn at
28.5 revolutions per minute but, while they appear to be moving slowly, that is
an illusion. Their tips swing at over 150 miles per hour and no bird could
survive being hit by a blade at that speed.
The
often-cited worst case for windmills is Altamont Pass in California where many
hawks and eagles have been killed. But even at Altamont, an early windmill
location with technology and turbine proximity judged inappropriate today, the
Center for Biological Diversity's lawsuit against its operators states: "We are not suggesting closing the Altamont wind farms,
rather that turbine owners take reasonable measures to reduce bird kills and
adequately compensate for impacts to imperiled bird populations."
Fortunately
birds simply avoid the blades of the newer wind turbines.
Studies at more recently designed wind farms tell us that bird
mortality at windmills is very low. A summary indicates that the average
number of birds killed annually across North America is between one and two per
turbine. Arguably the best of the intensive studies was carried out by
Canadian Ross James. His year-long field work at a Toronto wind turbine sited
in the middle of a fall migration route turned up three birds killed. He also
watched birds change course to avoid the turbine blades, an observation shared
by many other observers. His final conclusion: "The greatest threat to all
wildlife is still loss and/or degradation of habitat."
Against this data we have scare statements like one from a
dedicated hawk-watcher in the Chautauqua town of Ripley: "If a bird
doesn't get killed in Ripley, he may get killed in Rochester, if not there then
at Derby Hill, Prince Edward Island, Toronto...." Statements like this
together with intensive lobbying by such deeply concerned birders is deterring
the development of wind farms.
But consider what development at Ripley would mean. Over 20,000
hawks, vultures and eagles pass that location each spring to say nothing of
passerine migrants. If 35 wind turbines were erected there (more than the
number contemplated), the national average would suggest annual deaths of about
60 birds of all species, an infinitesimal fraction of the total number
traversing that region.
There is clearly a trade-off here but I believe that a
cost-benefit analysis comes down on the side of the wind turbines. I join my
birding colleagues in their concern for the death or injury of any bird, but I
suggest that wind turbines represent the least of their worries. For example, a
single feral cat kills more birds in a week than the average wind turbine kills
in over three years.-- Gerry Rising
Since this column was published, an important scientific study of the Chautauqua site has been published. This document provides extensive new data and is well worth close examination.
Among many other articles that speak to the issue of birds and windmills are the following:
and about windmills more generally: