First though valuable nesting places
must be defended from property thieves
After laying their eggs
take time out to clean their plumage the petrels
The south polar skua is a formidable opportunist
but the skuas have not chanced upon the petrels
they've been waiting for them
These birds do not need to go to the ocean for their food
The skuas can survive further south than any other predator
by exploiting the petrels' desperate need for bare rock
Even at the height of summer
less than 3% of Antarctica is free of ice
and nearly all of that exposed rock
is found in one place - the Antarctic Peninsula
Its long arm extends further north than the rest of the continent
so spring arrives here first