QUESTION:
What is the difference between the leopard seals, the weddell seals, and the
elephant seals and what special features do they have to survive in such
a cold enviornment?

        Alice Young's Class
        Lake Forest Elementary
        Lake Forest, California

ANSWER from Steven Downey, Doctoral Student, University of Illinois
            Wed, 19 Feb 1997 12:16:56 -0500

Dear Class,


Physically, elephant seals are much larger than leopards or weddells.
Elephant seals can weigh in at hefty 8,000 pounds.  Leopards typically
weigh 1,000 to 1,200 pounds; while weddells tip the scale at approximately
900 to 1,000 pounds.

The diets of these three also varies somewhat.  While all of them will
consume krill, fish, and squid, leopards also will eat penguins, and seal
pups (young).  Elephant seals also tend to dive deeper for their food than
do the other species.  Weddells, while they can dive relatively deep, favor
fast ice--away from open ocean--from which to do their hunting.  This way
they can avoid one of their main predators: killer whales.

As for surviving in the harsh climate of Antarctica, all seals have a thick
layer of blubber which protects them from the cold.  This fat layer means
that seals can swim through freezing water and still have a body
temperature of 95 degrees just 1.5 inches below their skin.  Since their
fat layers are much thicker than 1.5 inches, they don't seem to mind the
cold.

This layer of blubber also serves as a food reserve.  Seals don't eat as
much while raising pups, so the blubber provides nutrition which was stored
up from earlier in the year.

Thanks for your question!
Steven