Emperors of the Antarctic  One of the 17 types of penguins, the
Emperor penguin breeds on the sea ice surrounding Antarctica
during the dark, frigid austral winter. Using satellites during
the winter to observe these sea birds, U.S. biologists are
beginning learn more about the emperors and how they interact
with their environment.  Of the 17 species of penguins, only
emperor penguins breed during the extreme Antarctic winter, when
temperatures can drop to below -50C and winds can reach 300
kilometers per hour. The total number of emperor penguins is
unknown because new colonies are still being discovered, but
population estimates range from 135,000 to 175,000 breeding
pairs, living at about 40 sites on the sea-ice margin of
Antarctica. Seven of these colonies are in the Ross Sea, where
U.S. scientists have been studying them since the early 1960s.
The breeding cycle of emperor penguins begins in early April,
when the adults return to their traditional nesting sites. After
laying one egg, the female leaves t