QUESTION:
Does every female penguin lay an egg even if she has not mated?  What
happens to the unfertilized egg?

        Fourth graders in Greeley, CO, USA 
        Ms. Heisler's Class


ANSWER from David Lott, Researcher, Palmer Station, Antarctica 
            Fri, 14 Feb 1997 16:37:54 -0500

Dear Fourth Graders and Ms. Heisler,

No, every female penguin does not lay an egg.  There were several 
penguins, single females and pairs that didn't produce an egg.  In 
addition, there were females that laid eggs that weren't fertilized. 
These eggs, although the parents may incubate them for long periods 
of time, don't produce hatchlings.  Eventually, they will either be 
taken by skuas, will spoil, or will be left after the parents return 
to the sea.

Thanks for all your good penguin questions!

David Lott