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Re: Origin of flight



Yes, I've seen a red fox use the same strategy here in Vermont to catch mice
through the crusted over snow.
Scott
----- Original Message ----- 
From: "Dann Pigdon" <dannj@alphalink.com.au>
To: <dinosaur@usc.edu>
Sent: Thursday, September 13, 2007 10:34 PM
Subject: Re: Origin of flight


> Glen Ledingham writes:
>
> > Birds and small mammalian predators like cats and
> > foxes often pounce with high leaps rather than the
> > seemingly more efficient flat leaps, especially in
> > tall grass.  Perhaps this gives them better vision of
> > the prey and its evasive action or less resitance from
> > the ground cover.
>
> A vertical pounce reduces the chance of the prey detecting the predator
(and
> thus taking subsequent evasive action). The eyes of most terrestrial
> creatures are designed to look about in a horizontal plane, rather that to
> detect attacks from straight above. Vertical pounces take advantage of
that
> blind spot, plus I imagine that using gravity to accelerate the predator's
> mass towards the prey (and then crushing them against the ground) is
> probably more energy efficient than a horizontal leap (where forces are
> generated by muscles alone).
>
> Most vertical pouncers detect prey with their ears, and may not actually
see
> the prey at all before catching them. Arctic foxes and polar bears both
use
> an attack from above to snare creatures hidden beneath the snow (voles in
> the former, seals in the latter). Cats and foxes hunting in long grass
also
> tend to locate prey via sound.
>
> ___________________________________________________________________
>
> Dann Pigdon
> GIS / Archaeologist              geo cities.com/dannsdinosaurs
> Melbourne, Australia             heretichides.soffiles.com
> ___________________________________________________________________