Don't Forget that these figures are for Migratory birds. Australia
does not have the anywhere near the number of birds passing through
as the USA has transiting from the North American Palearctic regions
to the southern USA and Central and South America, but it would still
be an amazing figure.
Carl Clifford
On 06/09/2006, at 8:47 PM, Dave Torr wrote:
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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