Yan Ropert-Coudert - National Institute of Polar Research 1-9-10 Kaga, Itabashi-ku, 173-8515 Tokyo, Japan
David Grémillet - Affiliation D Grémillet: Centre d'Ecologie et Physiologie Energétiques, CNRS, 23 rue Becquerel 67087 Strasbourg, France
Peter Ryan - Percy FitzPatrick Institute of African Ornithology, University of Cape Town, Rondebosch 7701, South Africa
Akiko Kato - National Institute of Polar Research 1-9-10 Kaga, Itabashi-ku, 173-8515 Tokyo, Japan
Yasuhiko Naito - National Institute of Polar Research
Yvon Le Maho - Affiliation D Grémillet: Centre d'Ecologie et Physiologie Energétiques, CNRS, 23 rue Becquerel 67087 Strasbourg, France