QUESTION: 
We read that Adelie penguins molt their feathers yearly and while
they are molting they can't swim.  We wanted to know how long does the
molting last?  A week? A month?  And, why can't they swim while they are
molting?
          Third graders in Mrs.Rhonda Toon's room at
          Lamar County Elementary School in Central Georgia
                


ANSWER: Carol Vleck
Date: Thu, 30 Jan 1997 23:11:07 -0600
Palmer Station / United States Antarctic Program
Antarctica

Penguins depend on their very dense and waterproof coat of feathers to help
them maintain their body temperature in the cold Antarctic seas.  The
feathers don't last a life-time but have to be replaced yearly.  When the
new feathers grow in, they push the old feather out in big bunches.  But
while this is happening, the birds don't have that nice, insulative coat
because the new feathers aren't quite "done" yet but just poking through
the skin.  So the penguins have to stay on land or on ice floes for about
20 days until all the new feathers are mature.  Otherwise the penguins
would probably freeze to death in the water, just like we would if we tried
to stay in this cold water for very long without lots of protective layers.