Global analysis of emperor penguin populations ...

• Main Authors: LaRue, Michelle, Iles, David, Labrousse, Sara, Fretwell, Peter, Ortega, David, Devane, Eileen, Horstmann, Isabella, Viollat, Lise, Foster-Dyer, Rose, Le Bohec, Céline, Zitterbart, Daniel, Houstin, Aymeric, Richter, Sebastian, Winterl, Alexander, Wienecke, Barbara, Salas, Leo, Nixon, Monique, Barbraud, Christophe, Kooyman, Gerald, Ponganis, Paul, Ainley, David, Trathan, Phil, Jenouvrier, Stéphanie
• Format: Dataset
• Language: English
• Published: Dryad 2024
• Subjects: FOS Biological sciences; Emperor penguin; Aptenodytes forsteri; Bayesian method; high-resolution satellite imagery; Population modeling; Antarctic; Beaufort Island; Cape Crozier; Cape Roget; Cape Washington; Coulman Island; Crozier; Franklin Island; McMurdo Station; Roget; Ross Sea; Antarc*; Emperor penguins
• Online Access: https://dx.doi.org/10.5061/dryad.m63xsj48v; https://datadryad.org/stash/dataset/doi:10.5061/dryad.m63xsj48v

Like many polar animals, emperor penguin populations are challenging to monitor because of the species’ life history and remoteness. Consequently, it has been difficult to establish its global status, a subject important to resolve as polar environments change. To advance our understanding of emperor penguins, we combined remote sensing, validation surveys, and using Bayesian modeling we estimated a comprehensive population trajectory over a recent 10-year period, encompassing the entirety of the species’ range. Reported as indices of abundance, our study indicates with 81% probability that the global population of adult emperor penguins declined between 2009 and 2018, with a posterior median decrease of 9.6% (95% credible interval (CI) -26.4% to +9.4%). The global population trend was -1.3% per year over this period (95% CI = -3.3% to +1.0%) and declines likely occurred in four of eight fast ice regions, irrespective of habitat conditions. Thus far, explanations have yet to be identified regarding trends, ... : During the 2018 Antarctic field season, under permit #2019-006 granted by the National Science Foundation, our US-based team conducted aerial photography at emperor penguin colonies in the Ross Sea to add to robust validation of imagery. Our efforts included one flight via fixed wing aircraft over colonies distant from McMurdo Station and five flights via helicopter to a single colony (Cape Crozier) near the station. The five flights to Cape Crozier, 24 October to 15 November, were used to better understand population fluctuation through a single season. Our fixed wing survey took place on 31 October 2018, flying in the vicinity of Beaufort Island (ASPA 105), Franklin Island, Cape Washington (ASPA 173), Coulman Island, and Cape Roget. At each location (both by fixed wing and helicopter), we circled the colony 1-4 times, maintaining a minimum of 500 m horizontal distance from the periphery of the colony and a minimum altitude of 500 m. No behavioral disturbance to birds (e.g., rapid movement or dispersion of ...