Tuesday, February 23, 2016

Instead of dying, missing Antartic penguins may have relocated, scientist says

Scientists have not been able fully study how penguins emigrate between colonies

Population at Cape Denison was measured at about 160,000 in February 2011 but by December 2013 hit only 10,000
150,000 penguins that disappeared after a massive iceberg grounded near their colony in Antarctica may have relocated, and not died off as previously thought, the British daily the Guardian reported Tuesday.

The B09B iceberg, measuring some 100 square kilometers (38.6 square miles), grounded in Commonwealth Bay in East Antarctica in December 2010, the researchers from Australia and New Zealand wrote in the Antarctic Science journal earlier this month.

The Adelie penguin population at the bay's Cape Denison was measured to be about 160,000 in February 2011 but by December 2013 it had plunged to an estimated 10,000, they said.

The iceberg's grounding meant the penguins had to walk more than 60 kilometers (37 miles) to find food, impeding their breeding attempts, said the researchers from the University of New South Wales' (UNSW) Climate Change Research Center and New Zealand's West Coast Penguin Trust.

These observations, in addition to "hundreds of abandoned eggs," led the scientists to conclude that the penguin population was dying and that within 20 years would be gone all together.

Michelle De La Rue, a penguin population researcher at the University of Minnesota in the US, presents a new, more optimistic theory.

De La Rue believes that the penguins could simply have moved on to find a new home, similar to an incident in 2001 when another iceberg cut off the penguins living on Ross Island from the sea, said the Guardian.

“Just because there are a lot fewer birds observed doesn’t automatically mean the ones that were there before have perished,” said De La Rue.

“They easily could have moved elsewhere, which would make sense if nearby colonies are thriving,” she added.

The earlier study, which De La Rue was not involved with, noted that penguins living on the eastern fringe of the bay just eight kilometers from the ice berg blockage were thriving.

What has actually happened to the penguins may remain a mystery ,at least for the time being, as scientists have not been able fully study how penguins emigrate between colonies, said the Guardian.
 “I do not know what happened to these birds, but no one does for certain,” De La Rue said.


No comments: