There are similar stories from other regions. African penguins decreased from 1.5 million pairs a century ago to just 63,000 pairs by 2005. The number of Galapagos Islands penguins, the only species with a range that extends into the Northern Hemisphere, has fallen to around 2,500 birds, about one-quarter what it was when Boersma first studied the population in the 1970s.
The number of Adlie and Chinstrap penguins living on the Antarctic Peninsula, the northernmost part of the continent, has declined by 50 percent since the mid-1970s. Other species in Africa, South America, Australia, New Zealand, the Falklands Islands and Antarctica also have suffered significant population declines, Boersma said.
She recounts watching in 2006 as climate anomalies wreaked havoc on breeding of the same population of Emperor penguins that was featured in the popular 2005 film "March of the Penguins." The colony bred in the same location as in other years, where the ice is protected from the open sea and wind keeps snow from piling up and freezing the eggs. But in September, with the chicks just more than half-grown, the adults apparently sensed danger and uncharacteristically marched the colony more than 3 miles to different ice. The ice they chose remained intact the longest, but in late September a strong storm broke up the remaining ice and the penguin chicks were forced into the water. While the adults could survive, the chicks needed two more months of feather growth and buildup of insulating fat to be independent. The likely result of the climate anomaly, Boersma said, was a total colonywide breeding failure that year.
|Contact: Vince Stricherz|
University of Washington