SOME like it hot—but emperor penguins certainly don’t. A spell of
reduced sea ice has led to a dramatic halving of a population on the Antarctic
coast south of Tasmania, say French researchers.
Christophe Barbraud and Henri Weimerskirch of the CNRS Centre for Biological
Studies in Chizé looked at the size of a penguin colony around the Dumont
d’Urville research station. They found that numbers have dropped to about 3000
over the past 50 years. The highest mortality rates coincided with a period of
reduced sea ice between 1976 and 1980, and also with spells of warmer sea
temperatures (Nature, vol 411, p 183). This might affect the abundance
of krill, which the penguins eat, and shows that emperor penguins may be very
susceptible to environmental change.