What's Happening to the Adélie Penguins?

About 150,000 Cape Denison Adélie penguins are presumed to have died since December 2010 because of a giant iceberg blocking their access to food.  A study says that the B09B iceberg latched onto the Mertz Glacier Tongue and now extends the Common Wealth Bay by 1,120 square miles. The penguins are forced to travel an extra 37 miles in search of shrimp-like krill, fish, and squid.  The greater the distance the parents have the walk, the harder it is for the chicks to get their nutrients.  One co-publisher of the study, Chris Fogwill,  observed a lot of penguin casualties: "We saw a lot of dead carcasses, particularly the young, which was terrible to see."  The authors predict that the Cape Denison colony will disappear in 20 years unless the iceberg relocates.

However, not all researchers are convinced that the Adélie penguins have died; there's no concrete proof.  Michelle LaRue said, "Just because there are a lot fewer birds observed doesn't automatically mean the ones that were there before have perished.  They easily could have moved elsewhere, which would make sense if nearby colonies are thriving."  As for Fogwill's observations, LaRue counters that Adélie penguins always have dead birds scattered around because the carcasses decompose slowly in Antarctica's cold and dry climate.

It wouldn't be the first time Adélie penguins needed to immigrate to new feeding grounds. In 2001, an iceberg grounded in the southern Ross Sea, forcing them to relocate to nearby colonies until the ice broke up.  The Australian research team suggested the Cape Denison penguins joined other thriving nesting sites in the Commonwealth Bay, similar to the situation the Adélie penguins' faced in 2001. They noted patterns of abandoning and emigrating to other penguin colonies, evidence of the bird's adaption the changing ice conditions in the past. Although this theory sounds the most plausible, scientists still know little about how they migrate between colonies. The Adélie penguin population in Antarctica has only recently become tracked by satellites.

No one knows for certain what happened to these birds, so it's best not to jump to any extreme conclusions until further evidence surfaces.