Penguin Numbers Plummeting—Whales Partly to Blame?
Krill declines in parts of Antarctica linked to warming, whales, study says.
The problem appears to be a shortage of krill, the seabirds' primary fare, caused by rising regional air temperatures and rebounding populations of hungry whales.
Fisheries biologist Wayne Z. Trivelpiece of the National Marine Fisheries Service in La Jolla, California, has been monitoring colonies of chinstrap and Adélie penguins since the mid-1970s.
Because Trivelpiece regularly bands and monitors individual penguins, he's been able to uncover a key factor in the collapse: Far fewer young penguins are surviving their first winter on their own, because they're having a hard time finding krill.
"It's gone from about half of the chicks surviving in the 1970s and mid-1980s to only about one tenth now," Trivelpiece said.