Emperors in Hiding: When Ice-Breakers and Satellites Complement Each Other in Antarctic Exploration.

International audience : Evaluating the demographic trends of marine top predators is critical to understanding the processes involved in the ongoing rapid changes in Antarctic ecosystems. However, the remoteness and logistical complexity of operating in Antarctica, especially during winter, make su...

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Bibliographic Details
Published in:PLoS ONE
Main Authors: Ancel, André, Cristofari, Robin, Fretwell, Peter T, Trathan, Phil N, Wienecke, Barbara, Boureau, Matthieu, Morinay, Jennifer, Blanc, Stéphane, Le Maho, Yvon, Le Bohec, Céline
Other Authors: Département Ecologie, Physiologie et Ethologie (DEPE-IPHC), Institut Pluridisciplinaire Hubert Curien (IPHC), Université de Strasbourg (UNISTRA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Centre Scientifique de Monaco, British Antarctic Survey (BAS), Natural Environment Research Council (NERC), Australian Antarctic Division (AAD), Australian Government, Department of the Environment and Energy, IPEV (programme 137)
Format: Article in Journal/Newspaper
Language:English
Published: HAL CCSD 2014
Subjects:
Online Access:https://hal.archives-ouvertes.fr/hal-01015195
https://hal.archives-ouvertes.fr/hal-01015195/document
https://hal.archives-ouvertes.fr/hal-01015195/file/PlosOne-colonies-2014.pdf
https://doi.org/10.1371/journal.pone.0100404
Description
Summary:International audience : Evaluating the demographic trends of marine top predators is critical to understanding the processes involved in the ongoing rapid changes in Antarctic ecosystems. However, the remoteness and logistical complexity of operating in Antarctica, especially during winter, make such an assessment difficult. Satellite imaging is increasingly recognised as a valuable method for remote animal population monitoring, yet its accuracy and reliability are still to be fully evaluated. We report here the first ground visit of an emperor penguin colony first discovered by satellite, but also the discovery of a second one not indicated by satellite survey at that time. Several successive remote surveys in this coastal region of East Antarctica, both before and after sudden local changes, had indeed only identified one colony. These two colonies (with a total of ca. 7,400 breeding pairs) are located near the Mertz Glacier in an area that underwent tremendous habitat change after the glacier tongue broke off in February 2010. Our findings therefore suggest that a satellite survey, although offering a major advance since it allows a global imaging of emperor penguin colonies, may miss certain colony locations when challenged by certain features of polar ecosystems, such as snow cover, evolving ice topology, and rapidly changing habitat. Moreover our survey shows that this large seabird has considerable potential for rapid adaptation to sudden habitat loss, as the colony detected in 2009 may have moved and settled on new breeding grounds. Overall, the ability of emperor penguin colonies to relocate following habitat modification underlines the continued need for a mix of remote sensing and field surveys (aerial photography and ground counts), especially in the less-frequented parts of Antarctica, to gain reliable knowledge about the population demography and dynamics of this flagship species of the Antarctic ecosystem.