Text 5962, 55 rader
Skriven 2007-09-12 07:53:14 av Ward Dossche (2:292/854)
     Kommentar till en text av Martin Atkins
Ärende: Re: Global Warming
==========================
Martin,
 
MA> If you take into account even the most recent fluctuations in global
MA> atmospheric temperatures then the conclusion would be that both seals
MA> and polar region bears would be adequately equipped to deal with a
MA> change in climatic circumstances.
 
One can only theorize about that, I think. The seals upon which Polar bears
prey need the ice to give birth to their cubs, it's core to their survival as
it provides a quick getaway from its main predator.
 
A seal on land is a sitting duck for any bear, no chance of escape.
 
Polar bears also need the ice to pounce on their prey. Although they swim well
they can under normal circumstances never catch a seal, dolphin, porpoise,
beluga, narwhal or walrus in the water.
 
MA> Having said that, this current warming faze is not comparable
MA> to past epochs. I don't believe this is because mankind will make
MA> any significant impact on global temperatures but rather that we
MA> have encroached on the habitat of these species and this in
MA> itself has led to less diversity of terrain and so the ability
MA> to adapt through the process of natural selection has been seriously
MA> compromised.
 
As mankind does not inhabit the icefields which comprise the habitat of Polar
bears and seals, your statement does not compute.
 
The argument of Churchil in Canada and other remote communities is not a valid
comparison/argument as they are less than a needle in the haystack.
 
MA>WD> 2) They are built to den in the snow and the ice. Polar bears are
MA>WD> not made to dig a hole in the ground to den in and have their cubs.
 
MA> But they can do it. :)
 
No, they can't ... Digging a hole is no issue, but building a den in soil would
be impractal. It seems Polar bears could not survive that (too warm).
 
MA> Thanks Ward. I was unaware of the merging of two branches of one
MA> specie in the face of environmental change that can be studied
MA> today.
 
I had to learn that too. Had Bob Seaborn and others not attracted my attention
to it I would not have known.
 
In the meantime it has surfaced that in some zoos Polar bears have been made to
mate with Grizzlies with a fair degree of success. I'll see what I can dig-up
about that (my friend is the executive director of the European Association of
Zoos and Aquaria).
 
 \%/@rd

--- D'Bridge 2.74
 * Origin: Many Glacier -o=O=o- Preserve - Protect - Conserve (2:292/854)