Monday, April 19, 2010

New Paper on King Penguins

Original Paper

Do penguins dare to walk at night? Visual cues influence king penguin colony arrivals and departures
Anna P. NesterovaContact Information, Céline Le Bohec2, 3, David Beaune3, Emeline Pettex1, Yvon Le Maho3 and Francesco Bonadonna1
(1)  Behavioural Ecology Group, CEFE–CNRS, 1919 route de Mende, 34293 Montpellier, Cedex 5, France
(2)  Centre for Ecological and Evolutionary Synthesis, Department of Biology, University of Oslo, PO Box 1066, Blindern, 0316 Oslo, Norway
(3)  Département d’Ecologie, Physiologie, et Ethologie, IPHC–CNRS, 23 rue Becquerel, 67087 Strasbourg, Cedex 2, France
Received: 15 June 2009  Revised: 8 February 2010  Accepted: 10 February 2010  Published online: 9 March 2010
Communicated by C. Brown
Orientation based on visual cues can be extremely difficult in crowded bird colonies due to the presence of many individuals. We studied king penguins (Aptenodytes patagonicus) that live in dense colonies and are constantly faced with such problems. Our aims were to describe adult penguin homing paths on land and to test whether visual cues are important for their orientation in the colony. We also tested the hypothesis that older penguins should be better able to cope with limited visual cues due to their greater experience. We collected and examined GPS paths of homing penguins. In addition, we analyzed 8 months of penguin arrivals to and departures from the colony using data from an automatic identification system. We found that birds rearing chicks did not minimize their traveling time on land and did not proceed to their young (located in crèches) along straight paths. Moreover, breeding birds' arrivals and departures were affected by the time of day and luminosity levels. Our data suggest that king penguins prefer to move in and out of the colony when visual cues are available. Still, they are capable of navigating even in complete darkness, and this ability seems to develop over the years, with older breeding birds more likely to move through the colony at nighttime luminosity levels. This study is the first step in unveiling the mysteries of king penguin orientation on land.
Keywords  Short-range navigation - King penguins - Seabirds - Visual landmarks - Nocturnal movements -  Aptenodytes patagonicus

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