Subject: Re: Whale Questions

Robert Kenney (rkenney@gsosun1.gso.uri.edu)
Wed, 16 Dec 1998 17:14:10 -0500

At 15:58 12/14/98 +0000, you wrote:
> Hi I'm Thomas,
>    I'd like to ask a few questions. I'm a fifth grader at New Durham
>Elementary. In New Hampshire. My first question is how long do whales
>sleep or rest? 

We sometimes see humpback or right whales lying very still at the surface
for an hour or two.  It looks like they might be sleeping, but we can't
really be sure.

>What's a baby whale weigh? 

It depends on the kind of whale.  The biggest whales are blue whales, and a
baby blue whale can weigh more than 5,000 pounds when it is born.  They grow
really fast, too - maybe 200 pounds each day.

>What can we do to help whales? 

Lots of people think that there should be a really easy answer to that
question - something like make everybody in the world stop killing whales.
But it isn't so easy.  The best way to help whales in the long run is to
think!  For the rest of your life - think about how everything that you do
affects the the natural environment of the world, and how it would be if all
of the other billions of people in the world did the same thing.

>My last question is can they see in color?

Maybe not the same way that we do.  Whales are really too big to do
experiments on, but we can study dolphins.  They seem to have pretty good
vision.  But their retina (the lining inside the back of the eyeball which
receives the light and send nerve signals to the brain) is different than
ours.  We have rods for seeing fine details and in dim light and cones for
seeing color, but dolphins have mainly rods.  Their eyes are mainly
sensitive to blue and green light, but if you think about where they live,
most of the light that reaches them is blue and green.

Cheers,
Dr. Bob

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 | Robert D. Kenney, Ph.D.                       rkenney@gso.uri.edu |
 | University of Rhode Island                                        |
 | Graduate School of Oceanography                                   |
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