The Australian research team also suggests the Cape Denison penguins could have emigrated to other nesting sites. They note that abandoned and recolonized penguin colonies are found throughout Antarctica, evidence of the bird's adaptive response to changing ice conditions in centuries past.
The Cape Denison Adélie penguin colony was first visited in 1913 during Australian explorer Douglas Mawson's Antarctica expedition. The Australian researchers revisited the colony in 2013, during an expedition to recreate Mawson's voyage. (The year 2013 saw heavy sea ice, and the expedition had to be rescued offshore East Antarctica.)
The researchers thoroughly documented the penguin population during their visit. On the same trip, the research team also discovered thriving Adélie penguin colonies elsewhere in Commonwealth Bay. The finding makes it more plausible that some of the birds affected by the iceberg could have gone elsewhere. However, scientists still know little about how the penguins emigrate between colonies. The Adélie penguin population in Antarctica has only recently become tracked by satellites.
"What's happening in Commonwealth Bay provides a natural experiment of what we might anticipate for the future. I must stress B09B is not thought to be directly the result of climate change, but it does provide an important insight into processes that could operate in a warmer world," Turney said. "We do hope to get back to Cape Denison to continue monitoring the penguins and track what we hope will be a recovery if (or when) the giant iceberg B09B finally moves."
Adélie penguins breed between October and February. Adélie penguins must travel repeatedly from the colonies into the adjacent ocean to find the fish and krill that they eat.
Unlike emperor penguins, which breed on pack ice during the Antarctic winter, Adélie penguins breed during the Antarctic summer (Octover through February) and live on the continent. Adélie penguins travel back and forth from their nesting colonies to the ocean to hunt for fish and krill.
The arrival of B09B has prevented sea ice from leaving the bay, forcing the penguins to walk farther for food. As a result, the penguin population has experienced an order of magnitude collapse in numbers, Turney said.
While the Adélie population has dropped along the Antarctic Peninsula, the colonies in East Antarctica are growing, LaRue said. As of 2011, there were approximately 7 million Adélie penguins in Antarctica. "Losing 150,000 birds - even if that were true - is hardly apocalyptic," LaRue said.
Charming Chick Photos: Antarctica's Baby Penguins Images of Melt: Earth's Vanishing Ice Images: Adélie Penguins Cope With Changing Sea Ice Conditions Copyright 2016 LiveScience, a Purch company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.
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