title: Emperors in hiding: when ice-breakers and satellites complement each other in Antarctic exploration.
abstract: 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.
authors: Université de Strasbourg, Institut Pluridisciplinaire Hubert Curien, Strasbourg, France; Centre National de la Recherche Scientifique, UMR 7178, Strasbourg, France.
authors: André
authors: A
authors: Ancel
authors: Université de Strasbourg, Institut Pluridisciplinaire Hubert Curien, Strasbourg, France; Centre National de la Recherche Scientifique, UMR 7178, Strasbourg, France; Centre Scientifique de Monaco, LEA-647 BioSensib, Monaco, Principality of Monaco.
authors: Robin
authors: R
authors: Cristofari
authors: British Antarctic Survey, Cambridge, United Kingdom.
authors: Peter T
authors: PT
authors: Fretwell
authors: British Antarctic Survey, Cambridge, United Kingdom.
authors: Phil N
authors: PN
authors: Trathan
authors: Australian Antarctic Division, Kingston, Tasmania, Australia.
authors: Barbara
authors: B
authors: Wienecke
authors: Université de Strasbourg, Institut Pluridisciplinaire Hubert Curien, Strasbourg, France; Centre National de la Recherche Scientifique, UMR 7178, Strasbourg, France.
authors: Matthieu
authors: M
authors: Boureau
authors: Université de Strasbourg, Institut Pluridisciplinaire Hubert Curien, Strasbourg, France; Centre National de la Recherche Scientifique, UMR 7178, Strasbourg, France.
authors: Jennifer
authors: J
authors: Morinay
authors: Université de Strasbourg, Institut Pluridisciplinaire Hubert Curien, Strasbourg, France; Centre National de la Recherche Scientifique, UMR 7178, Strasbourg, France.
authors: Stéphane
authors: S
authors: Blanc
authors: Université de Strasbourg, Institut Pluridisciplinaire Hubert Curien, Strasbourg, France; Centre National de la Recherche Scientifique, UMR 7178, Strasbourg, France; Centre Scientifique de Monaco, LEA-647 BioSensib, Monaco, Principality of Monaco.
authors: Yvon
authors: Y
authors: Le Maho
authors: Université de Strasbourg, Institut Pluridisciplinaire Hubert Curien, Strasbourg, France; Centre National de la Recherche Scientifique, UMR 7178, Strasbourg, France; Centre Scientifique de Monaco, LEA-647 BioSensib, Monaco, Principality of Monaco.
authors: Céline
authors: C
authors: Le Bohec
mesh_terms: D000818:Animals; D000864:Antarctic Regions; D001947:Breeding; D017753:Ecosystem; D005260:Female; D007053:Ice; D008297:Male; D011156:Population Density; D063809:Satellite Imagery; D046429:Spheniscidae / Q000254:growth & development / Q000502:physiology*
chemical_list: D007053:Ice