The first emperor penguin colony. (Credit: © Robin Cristofari/CNRS/Institut polaire français IPEV)
ScienceDaily (Nov. 8, 2012) —
While about 2500 chicks of emperor penguins are raised this year at the
colony close to the French Dumont d'Urville Station, two new colonies
totalling 6000 chicks have just been observed about 250 km away, near
Mertz Glacier by the scientists Dr André Ancel and Dr Yvon Ancel, from
the Institut Pluridisciplinaire Hubert Curien in Strasbourg (CNRS and
Université de Strasbourg). Since a pair of emperor penguins may only
successfully raise one chick a year, the population of breeding emperor
penguins in this area of the Antarctic can therefore be estimated to
more than about 8500 pairs, about three fold that previously thought.
The two new colonies have been revealed on 1st and 2nd November,
during the late winter season trip of the MSS Astrolabe1 towards Dumont
d'Urville. They are located on the winter sea ice. This ice surrounds
the remains of the Mertz Glacier, from which a large ice wall, 80 km
long, 40 km wide and 300-400 m thick has separated. These may be two
sub-populations originating from the initial Mertz colony which,
following the Mertz Glacier break, are attempting to settle again on
favorable surroundings. One accounts for about 2000 chicks and the
second for about 4000 chicks.
Dr André Ancel had suspected the existence of an emperor penguin
colony near the Mertz Glacier since 1999, when with Dr Barbara Wienecke
(Australian Antarctic Division), they observed thousands of emperor
penguins going back and forth in the Mertz glacier area. Dr Peter
Fretwell and Dr Phil Trathan of the British Antarctic Survey localised
this colony in 2009 based on the images from space of emperor penguin
nitrogen dejections on the sea ice. However, the break of the Mertz
glacier in 2010 questioned the fate of this colony. New satellite images
obtained since then suggested that the birds might attempt breeding on
different sites. Over the last 13 years all French attempts to find the
birds had failed, due to the harsh winter conditions and the summer
disappearance of the sea ice where the Emperors breed.
This year, the human, logistic and environmental conditions finally
came together. The French Polar Institute (IPEV) then decided to modify
the Astrolabe's route to enable Dr André Ancel and Dr Yvon Le Maho to
find this population. A good climate window, the excellent knowledge of
the environment by the IPEV logistic teams, the expert navigational
skill of the Astrolabe crew in the ice and the essential helicopter
support in such areas, have allowed for the success of this detection.
The break of the Mertz Glacier had profoundly modified the environment
into a chaos of small icebergs and sea ice. The French scientists
discovered that the initial colony seen from space by their British
colleagues had been split over two sites. The first, whose localisation
had been recently indicated by the British, accounts for about 2000
chicks, whereas 4000 are being raised in the second. The second site was
discovered by chance, 15 km from the first, while conducting a
scientific helicopter survey.
Story Source:
The above story is reprinted from materials provided by Centre national de la recherche scientifique (CNRS).
Note: Materials may be edited for content and length. For further information, please contact the source cited above.
Centre national de la recherche scientifique (CNRS) (2012, November 8). Two new emperor penguin colonies in Antarctica.
ScienceDaily. Retrieved November 9, 2012, from http://www.sciencedaily.com /releases/2012/11/121108181439.htm
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