RE: T-rex vision

[Tim Madden <TMADDEN@medicode.mhs.compuserve.com>]

 Larry Smith writes:
> Predators _are_ more sensitive to certain patterns of motion.  My cat is
> not at all intereted in up-and-down motion, but he can't stop himself from
> pouncing on horizontal motion.  But if I moved a piece of _meat_
vertically,
> suddenly he is interested.  Motion-detection is _not_ the single, driving
> mechanism for prey acquisition for anything more complex than a frog -
which
> was the point the book made and the movie did not.  So now we have burned
> into the public conciousness the perception that t'rex hunted just like a
> frog.  And even the movie couldn't bother to be consistant about it, they
> made much of the vision thing, but when it came time to do the lawyer
joke,
> the lawyer moved no more than the digger and girl did but the 'rex saw
_him_
> pretty good.  Like I said, bad research and poor script writing.

I disagree with it being the pattern of motion. My experience with cats
(I inherited two through marriage, and have had a few during my life) is
that the speed and suddenness of the motion is what attracts attention.
Both my cats have chased a spider crawling up a wall, and my wife is
amused when I get the female to nod by moving my hand up and down. But
short, quick jerks on a string will get a pounce faster than dragging. The
same with praying mantises (mantie?). My dad collects them where ever he
can find them, so I have spent some time watching them. Sudden, quick
hand motions toward them will cause them to flee or go into a defensive
posture. Slow, delibrate movments tend to be ignored.

Anyway, setting aside the JP movie, standing still _might_ not attract
the attention of a T-Rex. But I doubt it would miss you if you were
standing a foot away right in front of it. It might regard you as not
worth the bother.

Tim