[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: My Gr. 9 Science Fair Project: Questions



Dr Paul M.A. Willis wrote:

 > Do not underestimate the stealth of a croc on the hunt. There are numerous
 > documentaries that show zebras and wildebeast quietly drinking at a river
 > only to find that there is a croc lying in wait in the middle of them.
 >
 > [ Sorry to interject, but dinosaurs probably had better color vision
 >   than most mammals and may have been sensitive to optical polarization
 >   as well.  The latter would be particularly helpful in allowing an
 >   animal to see under the surface of the water because the polarization
 >   of reflected light would be different from the polarization of light
 >   transmitted from under the water's surface.  -- MR ]

Humans also have good color vision.

Having *been* to the everglades, I can tell you, croc in the water
are blessed hard to see, even *with* color vision.

For one thing, as often as not the water is quite opaque.

All one can generally see of a croc in the water is the tiny
nose sticking out - if that much.  In an area of reeds or
rushes even that would be rather hard to spot.

swf@elsegundoca.ncr.com         sarima@ix.netcom.com

The peace of God be with you.