And why don't they run into tall trees the same way??
73
Gary K4FMX
> -----Original Message-----
> From: towertalk-bounces@contesting.com [mailto:towertalk-
> bounces@contesting.com] On Behalf Of rdhinkle@sbcglobal.net
> Sent: Sunday, December 10, 2006 11:07 PM
> To: towertalk@contesting.com
> Subject: Re: [TowerTalk] Commercial Comms Towers and Bird Strikes
>
> OK guys, I'll take a poke at this too.... As a long time ham and
> professional wildlife biologist, I can tell you from personal experience
> that tall communication towers are lethal to songbirds, and in massive
> quantities. On one occasion, I picked up a heaping full bushel of
> neotropical migratory songbirds (warblers, thrushes, orioles, tanagers and
> others) under the nearest TV tower in Lansing Michigan, near the MSU
> campus.
> Tall towers continue to kill as many hundreds of thousands of migrating
> songbirds as they move through Central America, Mexico, the US and Canada
> during both spring and fall migrations. Exhaustion only seems to be a
> factor
> on foggy nights, when the birds become confused by the lighting.
> Otherwise,
> it's mainly direct strikes against the tower itself and the numerous guy
> lines that each tower needs. Nearly all songbirds migrate at night (tough
> to
> avoid what you can't see) so most of the fatalities are between dusk and
> dawn. The recent addition of a jillion cell phone towers adds to the
> carnage. One publication states:
> _________________________________________________________
>
> "Lighted communication towers turn out to be one of the more serious
> problems for birds, especially for migratory species that fly at night.
> One
> study began its conclusion with, "It is apparent from the analysis of the
> data that significant numbers of birds are dying in collisions with
> communications towers, their guy wires, and related structures." Another
> report states, "The main environmental problem we are watching out for
> with
> telecommunication towers are the deaths of birds and bats."
>
> This is not news, as bird collisions with lighted television and radio
> towers have been documented for over 50 years. Some towers are responsible
> for very high episodic fatalities. One television transmitter tower in Eau
> Claire, WI, was responsible for the deaths of over 1,000 birds on each of
> 24
> consecutive nights. A "record 30,000 birds were estimated killed on one
> night" at this same tower. In Kansas, 10,000 birds were killed in one
> night
> by a telecommunications tower. Numerous large bird kills, while not as
> dramatic as the examples cited above, continue to occur across the country
> at telecommunication tower sites.
>
> The number of telecommunication towers in the U.S. currently exceeds
> 77,000,
> and this number could easily double by 2010. The rush to construction is
> being driven mainly by our use of cell phones, and to a lesser extent by
> the
> impending switch to digital television and radio. Current mortality
> estimates due to telecommunication towers are 40 to 50 million birds per
> year. The proliferation of these towers in the near future will only
> exacerbate this situation. "
> ___________________________________________________________
>
> The mechanisms involved in migration by various species remain poorly
> understood, whether magnetic fields or celestial navigation (night) or
> light
> polarization, landmarks, magnetic fields, regional low frequency sounds or
> other means (day), most migratory methods seem to lead massive flocks of
> individual or mixed species along "ancestral" migration routes. When we
> put
> up a tall tower, they fly into it. The addition of many new towers to the
> additional losses from constant habitat loss result in a marked, long-term
> decline in migratory songbird numbers. I don't think that most ham towers
> are tall enough to contribute significantly to bird strike losses, though
> certainly some occur. Perhaps the switch to commercial satellite radio,
> TV,
> voice and data comms and other communications will bring the day when the
> iron comes down and the skies are clear again.
>
> If you want to see something impressive, start watching Doppler Radar
> reports from the Cuba-Florida-Georgia region starting in early April
> through
> early May, and see hundreds of millions of songbirds lift off as darkness
> falls each evening and head north. On one hand, it's a pretty stunning
> radar
> report; on the other hand, it shows us how finite songbird populations
> are.
>
>
> Bob Hinkle, KK8ZZ
> Solon, Ohio 44139
> Grid: EN91gj
>
>
> _______________________________________________
>
>
>
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