Wow - so (excluding cats) say 230m a year - which would scale to around 20m
a year in Aus I would guess. Windfarms are totally insignificant overall,
but of course different structures would get different types of bird -
windows would mainly affect urban birds which tend to be common and/or
feral. Pesticides would be more widespread. Windfarms would probably
"target" specific species dependant on location of course.
On 06/09/06, Carl Clifford <> wrote:
The US Fish and Wildlife Service has a Fact Sheet on migratory bird
mortality http://www.fws.gov/birds/mortality-fact-sheet.pdf which gives
estimates of deaths from impacts etc. which are rather astonishing. I quote
the lower estimates for the worst causes
of death.
Building window impacts - 97 million
Communications towers -4 to 5 million
Cars - 60 million
Wind turbines - 33 thousand
Pesticides - 72 million
Oil and Wastewater pits - 2 million
Cats - no national figures, but they give estimates for the state of
Wisconsin of mortality by rural domestic cats - 39 million
These figures are the lower estimates, the upper estimates are up to 10
fold.
I make no further comments on these figures, except that I would be very
intersted in seeing extrapolations of them for Australia
Carl Clifford
On Wednesday, September 06, 2006, at 07:07PM, Dave Torr <
> wrote:
>I recall an estimate (in Handbook of the Birds of the World - can't
recall
>the volume) that in the USA alone between 500k and 5m birds a year died
in
>building collisions, and I would assume that our data would be pro-rata,
so
>after adding in roadkills etc I guess that windfarms are a very minor
>factor.
>
>Of course we will probably never know whether the birds "saved" through
less
>greenhouse gases are more or less than those lost through collisions!
>
>There is I think too much focus on wind and solar (which are intermittent
>technologies) and not enough on energy conservation and storage (needed
to
>cope with wind and solar) - we need a balanced approach to reduce our
impact
>on the planet. There are also technologies such as extracting energy from
>hot rocks that seem to have a lot of promise (and minimal impact) but
have
>little publicity.
>
>On 06/09/06, Greg <> wrote:
>>
>> Hi Evan,
>>
>> Thanks for your reply. As someone involved in the industry do you have
>> access to accurate data on the numbers of birds and bats killed by wind
>> farms each year? I appreciate the fact that some impacts can be
mitigated
>> but still believe that solar would have the least impact on ecosystems.
>>
>> I am strongly anti-nuclear so am not a pro-nuke person opposing wind
farms
>> from that direction. I just don't want us to replace one technology
that
>> has an adverse impact on the planet with another that, potentially, can
>> have
>> a major impact. The noise and visual pollution are minor issues
compared
>> with the potential bird and bat kill impacts. I agree that there are a
>> number of other structures and machines (motor vehicles, planes etc.)
that
>> kill birds and bats but wind farms are now an additional hazard for
>> migratory birds and bats to deal with. So if we want wind farms we
have
>> to
>> be sure that the level of kill is low enough to not adversely impact on
>> populations or whole species.
>>
>> I think that people presenting the argument that it is a choice between
>> coal
>> or wind farms are over-simplifying the issue. There are other viable
>> options.
>>
>>
>> Greg Clancy
>>
>>
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