Two massive icebergs in Antarctica's Ross Sea have altered local weather conditions enough to endanger some of the continent's penguin breeding colonies, according to the National Science Foundation.
A small colony of Adelie penguins at Cape Royds will "fail totally" this year, according to biologist David Ainley of H.T. Harvey & Associates of San Jose, an ecological consulting firm.
The numbers at a larger colony at Cape Crozier--normally about 130,000 breeding pairs--"are on the low side" of the normal range this year, he added. Many pairs are unable to reach the breeding grounds because of the abnormally large amounts of sea ice.
Meanwhile, a small colony of about 1,200 emperor penguins at Cape Crozier failed to raise any chicks, according to Gerald Kooyman of the Scripps Institution of Oceanography. The birds probably abandoned efforts to breed when the icebergs, pushing southward, destroyed and closed off their usual breeding area, he said. The few chicks that were conceived either died in the egg or soon after birth.