QUESTION:.
How many eggs do penguins lay and what is their survival rate?

                From Emily - Hydesville, CA.
                Ginny Dexter's Class

ANSWER from Carol Vleck, Researcher, Palmer Station, Antarctica
            Fri, 7 Feb 1997 08:47:08 -0600

Hi Emily,
Some penguins, like the large Emperor and King penguins only lay a single
egg, but other kinds of penguins lay two eggs. Here on Torgersen Island the
Adelie penguins almost always lay two eggs, but if they lose the first egg
to a skua before the second is laid, they sometimes lay a third egg.
Occasionally an egg will not hatch because it is infertile or gets too cold
during development, but usually both eggs hatch if they haven't been eaten.
Penguin eggshells are very thick and that helps to keep the eggs from
breaking when they are laying on the rocks, being sat upon by the parent.
Many parents, especially the young parents, only raise one chick to the
point that it can take care of itself, however, and since the first hatched
chick is a little bigger than its sibling, it is often the second chick
that doesn't make it. One strange habit of some penguins like the
Rockhopper and Macaroni penguins, though, is to lay a smaller first egg and
then a larger second egg. The first egg hardly ever hatches, and in fact it
is often lost even before the second egg is laid. Biologists don't really
have a good ideas why the female lays this first small egg that hardly ever
lives.

Thanks for your question!
Carol