[TowerTalk] Potential New FCC Tower Construction Threat

[Jim Lux]

At 07:16 AM 12/11/2006, Joe Subich, W4TV wrote:


> > Also, no differentiation between 1,000' high midwestern TV
> > towers, and  100' high cell towers.  Might be interesting to
> > see if we're getting piles of bird carcases around cell
> > towers.
>
>They don't even get "piles of bird carcasses" around 1000' high
>midwestern TV towers.  I spent 15 years around a 1200' TV tower
>- with strobes - us outside Columbus Ohio through he 80's and
>most of the 90's.  That tower was responsible for the death of
>fewer than 2-3 dozen a year.  We would see a couple per month in
>the spring and fall with none in the winter and a rare carcass
>during the summer months.


There IS a discussion in the literature about this.  Given that the 
bird strikes occur at night, local scavengers might haul away some 
fraction of the carcasses.

Some researchers (in what I think is a very amateur radio like 
improvisation, although not done under the aegis of a ham license) 
took a marine X-band radar and turned it on its side, creating a 
"vertical fan" beam in an attempt to quantify this sort of thing.

I suspect that there really IS a huge uncertainty in the estimates, 
especially given all the confounding factors that come into play 
(weather, migration paths, tower characteristics, bird species, 
seasons and time of day).



>
>For DF&WS's "estimates" to be even in the ballpark, every one of
>the estimated 10,000 towers more that 800 feet tall in the US
>would have to claim 1000 birds a year ... In my opinion that
>number is simply not credible and is probably off by a factor
>of at least 10.


Perhaps, but, unfortunately for us, 4 million or 40 million, if it 
provides an excuse for a local jurisdiction to require an analysis 
that costs $10K, that's a pretty hefty burden for someone who puts up 
a tower once every 10 years.  (For a cell company installing 
thousands, it's not such a big deal.. the overall installation is 
bigger and more expensive than a ham tower)

Jim,W6RMK