Wind
Turbine Bird Kills
(This 1186th Buffalo
Sunday News column was first published on December 15, 2013.)
Wow!
Did you realize that as many as 50,000 birds are killed each year by wind
turbine collisions across North America?
As
I have presented that information, wind turbines seem to represent a serious
problem. Indeed, many people argue that such a total calls for a moratorium on
wind power. One individual, upset by the location of a wind farm on Ontario's
Amherst Island near a woodland where owls winter, has even called for a boycott
of Canadian products and travel to that country.
I
reject those calls for action and consider the latter an insane indictment of
our Canadian friends. It represents an extreme and irrational response based on
little or no understanding of the identified problem. Unfortunately, however,
it also represents a kind of thinking widespread among well-meaning people.
In
this column I seek to place in perspective the numbers on which that kind of
thinking is partly based.
As
it happens, a seminal paper by a group of Canadians headed by Anna Calvert of
Environment Canada has recently summarized a series of controlled research studies
of human-related causes of bird deaths in that country. Their paper gives us
the best currently available data comparing the specific causes of bird death
and I have drawn on their report published in the journal Avian Conservation
and Ecology for the following comparisons. That 50,000, however, represents the
total of bird deaths for all of North America. In it I have included the U.S.
Fish and Wildlife estimate for this country.
Fifty
thousand birds killed seems like a great many until
you consider the total number of bird deaths each year. It turns out that only
one out of 14,000 is due to those turbines. It should be clear that the general
effect of wind turbines on our bird populations is infinitesimal.
Well,
just what is killing those birds? For every one windmill death the following approximate
numbers are killed by other means: feral cats, 6000; domestic cats, 4000;
striking private homes, 1200; vehicle collisions, 750; the game bird harvest,
200; pesticides, 150; transmission tower kills, 101; striking commercial
buildings, 90; transmission line collisions, 65.
It
is worth considering a few of those numbers more closely.
Almost
3/4 of all of these human-related deaths are caused by cats:
43% by feral cats, 29% by domestic cats. Another way to think about those
numbers is to compare them with the effect of hunting. For every game bird
shot, 19 birds are killed by domestic cats, 28 by feral cats.
Can you understand then why I strongly support the Cats Indoors program of the American
Bird Conservancy and equally strongly oppose the Trap-Neuter-Return program that supports thousands of cats that are
killing birds and small mammals?
And
think too about transmission towers, those towers that support your cell phone
as well as radio and television stations. They kill over 100 times as many
birds as do wind turbines yet turbines are far more strictly regulated.
Okay,
tower kills represent a very small fraction of the hazards we erect for birds.
But research is suggesting ways to reduce those deaths as well.
Tower
height and the use of guy wires to support the structure have an effect on bird
deaths. A Michigan study found that guy wires increased the number of
fatalities by a factor of 16, and that tower height quadrupled that factor. By
constructing only un-guyed towers of medium height, many bird lives would be
saved.
Most bird
migration takes place at night, the birds foraging during the day to stoke up the
energy needed to continue. And at night they are easily
confused by lights. The results of one study suggests
that avian fatalities can be reduced by over 50% by removing
non-flashing/steady-burning red lights.
Here
is where you may be able to help. If you observe such a structure lighted at
night with steady lights, communicate the need for the simple but effective
change to flashing lights to local authorities.
This
has been a column burdened with mortality statistics. But Shakespeare reminds
us that there's a special providence in the fall of a sparrow. We cannot undo
civilization but we can do our best to minimize the devastation we
cause.-- Gerry Rising