Within the Western Ross Sea, there are six emperor penguin colonies of
widely different size that occur exclusively on sea ice. In 1990 a su
rvey of all six sites, two by close overflights and four from the grou
nd, showed that the breeding habitats were highly variable. The most i
mportant physical characteristics of these habitats appear to be stabl
e fast ice, nearby open water, access to fresh snow, and shelter from
the wind.