Paris - Emperor penguins in the Antarctic act as accurate indicators of climate change, French researchers revealed in a paper published in Nature magazine on Thursday.
Christophe Barbraud and Henri Weimerskirch say that the population of emperor penguins located near the French Antarctic base of Dumon-d'Urville went into sharp decline during the late 1970s at the same time as a prolonged spell of abnormally warm temperatures.
They say this could have had a fatal effect on their food supply.
The scientists decided to look for clues in data from monitoring of the penguin population going back to 1952 together with readings from a weather station just 500 metres away.
Continues Below ↓
This showed penguin numbers remaining stable at around 6 000 until 1975.
But over the following five years, the colony suffered a massive 50 percent fall in size.
The weather data throughout the 1960s revealed an average winter temperature of minus 17,3 degrees celsius.
This changed in the 1970s with extensive variations including unusually high figures producing an average of 14,7 degrees celsius.
Since then the temperature has been at an average of 16,6 degrees celsius and the size of the penguin population has stabilised again at around 3 000.
Barbraud and Weimerskirch, who are based at the Centre for Biological Studies at Villiers-en-Bois in western France, believe that the relatively high temperatures combined with the sharp decline in penguin numbers could be linked to food.
The animals' main diet consists of Antarctic krill, together with certain fish and squid.
The French scientists point to previous research which shows the availability of such prey is reduced when winter sea-ice cover is less.
"In years with high sea surface temperatures, emperor penguins probably have difficulties in finding food, which could increase mortality," they say in their report.
It is the male penguins which are likely to be hit particularly hard by such a situation.
They observe a four-month fast to provide continual protection of the single egg produced by breeding pairs during the Antarctic winter.
Not being able to find food quickly after this could prove fatal. - Sapa-AFP
|
StumbleUpon
Reddit
Digg
Delicious
Newsvine
Facebook
muti
Twitter
