Antarctic study digs for clues to penguin past

Adelie penguins live in the coldest environment on earth. Photo / James Borrowdale

Happy Feet's distant relatives might one day become victims of climate change.

Experts warn the effects of a warming climate could affect the small ecological niche in which Adelie penguins reside.

Scientists from the University of Auckland and Italy's University of Pisa are in Antarctica to search for clues about Adelie penguins' evolutionary past, and what this reveals about how they will respond to climate change.

Professor Carlo Baroni, professor of geomorphology at the University of Pisa, said penguins lived in the coldest environment on earth and if the temperature warmed, penguins couldn't migrate to a colder climate.

"If global warming increases and affects the Antarctic regions, penguins have no other place to go, so they must adapt or die."

The team left Scott Base this week for a month of collecting samples from two penguin rookeries. Over many years of habitation Adelie penguins leave layers of accumulated bones, eggshells, feathers, nests, and guano. This presents scientists with the opportunity to dig through the levels and gather DNA from long-dead penguins.

"It is very similar to an archaeological approach. We mark squares of one metre by one metre then layer by layer we excavate it and collect samples."

Professor Baroni, now on his 14th trip to Antarctica, said his team had previously uncovered samples as old as 40,000 years.

"We are at the limits of the capability of radiocarbon dating."

Auckland University's Yvette Wharton said the limited ecological niche of Adelie penguins made them excellent subjects for studying adaptive evolution. As their niche changed, she said, the penguins would have to change with it.

"As we are getting climate change occurring there is going to be quite a specific effect on their potential ecological niche. We're squishing them."

She said they would learn of past climatic changes, how the colony sizes had changed, and how the penguins had evolved to meet these new conditions.

"You can then use that as a model to see the types of things that might happen to an organism with environmental changes."

ADELIE PENGUINS

* Males and females come on land for just a few months each summer to breed and raise their chicks - a task mastered by "tag-team parenting" in minding the egg.
* Males arrive first to find the best spot and build a nest. When the females arrive, the males serenade their prospective mates with a sound described as a cross between a donkey and a stalled car.
* Females look for the fattest male they can find, as their partner must spend the first two weeks sitting on the eggs without any chance to go in search of food.