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Climate
change is not just impacting far-away penguins and polar bears.
Robins, Pine Siskins and 175 other winter birds in the United States
are moving farther north and farther inland in response to warmer
temperatures, according to a recently released study by the National
Audubon Society. Dr. Greg Butcher, Audubon’s Director of Bird
Conservation, led the study and arrived at his conclusions after
analyzing 40 years’ worth of Christmas Bird Counts. The National
Audubon Society
has posted the technical reports, legislative priorities, and a
wealth of information about birds and climate change at
http://www.audubon.org/news/pressroom/bacc/index.html. Dr.
Butcher’s Birds and Climate Change Web cast can be seen by
registering at
http://www.audubon.org/bird/bacc/webcast.html.
The reasons for wildlife population movement and for climate pattern
change can be complex and unclear. However, Dr. Butcher, who has
studied changes in bird populations for decades, is unequivocal in
his conclusion that the average January temperature increase of five
degrees Fahrenheit over this same 40-year period is the cause of
these northward movements. He argues that a species-by-species
explanation can’t account for the vast number of species moving
north. Of course, more people are feeding birds than 40 years ago,
but this factor can’t explain why Spruce Grouse, Red-breasted
Mergansers and so many others not dependent on feeders are also
heading north. Some birds, notably grassland species such as
meadowlarks and Burrowing Owls, moved south, often because of
habitat loss and lack of suitable habitat farther north. Other birds
did not move to the warmer northern habitat because along with
warming came a drying trend, making the northern habitats unsuitable
for the species.
Dr. Butcher is also unequivocal in his
conclusion that the increase in
greenhouse gases over this same 40-year period is the cause of the
warmer temperatures. He rests his case on the overwhelming evidence
compiled by the UN-sponsored International Panel on Climate Change,
including thousands of peer-reviewed scientific papers, and the
conservative consensus of hundreds of climate experts. Dr. Butcher
points to a number of threats to bird populations from climate
change,
including:
• Disappearance of polar ice and glacial habitats critical to birds
such as penguins, Kittlitz’s Murrelets, Ivory Gulls, and Spectacled
Eiders
• Thawing of tundra used as nesting habitat by birds such as
Buffbreasted
Sandpipers and Snowy Owls
• Erosion of beach habitat critical to birds such as Piping Plover,
Seaside and Salt Marsh Sparrows
• Loss of coastal up-welling which eliminates important food sources
for Cassin’s Auklets and
other birds
• Drying up of prairie potholes habitat used by ducks for nesting
• Shrinking of malarial-free zones critical for the survival of
native Hawaiian birds
• Loss of alpine habitats used by mountain-top bird species
The bird winning the prize for moving
the farthest north also presents us
with the deepest irony. The Purple Finch, moving north 438 miles, is
in the
same family, Fringillidae, as the canary. Canaries were used by coal
miners
to warn them of the presence of the invisible gases methane and
carbon
monoxide. If the canaries got sick, the miners would put on their
gas
masks and escape. Now another Fringillidae is showing us its
sensitivity
to another invisible gas coming from coal – carbon dioxide; and now
that
we’ve taken the coal out of the mine, burned it, and poured this
pollutant
into the air and oceans, there is no place to run and no gas mask to
wear.
Let’s hope we heed this Fringillidae’s warning before it’s too late.
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