Fifty-seven years ago last
week – September 27, 1962 – Rachel
Carson published Silent Spring, the book that really got us thinking about what
we are doing to the environment.
Silent Spring predicted more
future consequences from indiscriminate use of pesticides and other ways that
we are abusing our world. Those predications are coming true.
A
dramatic new analysis published in the journal Science says the U.S.-Canada
bird population is almost three billion birds smaller than it was 50 years ago.
The analysis is based on a study by seven research institutions in Canada and the
United States.
The number – 2.9 billion
fewer birds - is shocking, but not totally surprising. That fits with my
observations at the cottage, where songbirds once provided an abundance of joy.
A few finches and grosbeaks,
once a daily feature at our place, showed up a couple of months ago, bringing a
spark of hope. But this fall there is little birdsong around our place and
walks in the woods have not flushed one ruffed grouse.
Almost six decades after
Silent Spring, I am witnessing Silent Autumn.
Habitat loss and pesticides
are two proven causes of bird decline. There are fears now, however, that
changing climate is a contributing factor.
Scientists says there is no
evidence that climate change is directly killing birds. Changing climate is,
however, having indirect effects.
Recent
studies have reported huge declines in insect populations. Insects and birds
are hugely important to each other. Many birds eat insects for food. So fewer
insects to eat means more birds searching for food to stay alive.
More
importantly, rising world temperatures are bringing insects, and diseases they
carry, to places they have never been before. For instance, mosquitoes carrying
malaria, West Nile Virus (WNV) and other diseases are populating areas beyond
their historical range.
There
is a ton of Americans research on the impact of mosquito-borne disease on
birds. U.S. studies have detected the presence of the West Nile Virus in more
than 300 species of birds, including ruffed grouse.
Little
research has been done in Canada, possibly because nasty bugs and the nasty
things they transmit have been limited to warmer areas south of us.
That
is changing. Our temperatures are rising and bugs and viruses are moving north.
Ticks carrying Lyme Disease are one example. Mosquitoes transmitting the WNV
are another.
Canadian
research, especially into the impact of West Nile on birds, is urgently needed,
Thankfully
we are getting some, from Dr. Amanda MacDonald, a University of Guelph
researcher specializing in wildlife disease.
Her
study is building data on wild turkeys and ruffed grouse exposed to West Nile
in Ontario and Quebec. She is encouraging turkey and grouse hunters to help by
submitting blood samples from birds they have shot. The study supplies filter
strips for blood collection and postage-paid envelopes for submitting the
samples.
Birds
can be infected with West Nile when bitten by a mosquito which has bitten and
drawn blood from an infected bird or animal.
Not
all birds exposed to the virus become ill, or die. However, it does seem to hit
hardest the corvid family of birds, of which crows and jays are members.
American
research indicates that West Nile is reducing ruffed grouse populations.
MacDonald’s study will provide information about levels and locations of
exposure and could be a start to determining whether West Nile is a factor in
shrinking grouse populations.
It
also will be important for wild turkeys. Governments and private organizations
spent much time and money on reviving wild turkey populations in
Ontario. Any threat to that revival needs quick and thorough research.
We
must learn everything about what is killing the birds so we can do more to
prevent the losses. Not just because they are lovely to look at and wonderful
to listen to.
West
Nile, Lyme and other insect-borne diseases are becoming more common in our
world. So far this year the U.S. Centers for Disease Control has reported well
over 300 human cases of WNV, with 45 states and the District of Columbia
reporting exposure in mosquitoes, birds or humans.
Silent
Spring warned us 57 years ago. Now things that can hurt us are moving our way
and we need to be better informed, better prepared.
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