Using predicted patterns of 3D prey distribution to map king penguin foraging habitat

• Published in: Frontiers in Marine Science
• Main Authors: Proud, Roland, Le Guen, Camille, Sherley, Richard B., Kato, Akiko, Ropert‐Coudert, Yan, Ratcliffe, Norman, Jarman, Simon, Wyness, Adam, Arnould, John P. Y., Saunders, Ryan, Fernandes, Paul G., Boehme, Lars, Brierley, Andrew S.
• Other Authors: Pelagic Ecology Research Group, Scottish Oceans Institut, Centre for Ecology and Conservation, University of Exeter, Centre d'Études Biologiques de Chizé - UMR 7372 (CEBC), Université de La Rochelle (ULR)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), British Antarctic Survey (BAS), Natural Environment Research Council (NERC), School of Biological Sciences, University of Western Australia Australia, The University of Western Australia (UWA), Coastal Research Group, Department of Zoology and Entomology South Africa, Rhodes University, Grahamstown, School of Life and Environmental Sciences, Faculty of Science and Technology, Deakin University Burwood, School of Biological Sciences Aberdeen, University of Aberdeen, Scottish Oceans Institute University of St Andrews (SOI), School of Biology University of St Andrews, University of St Andrews Scotland -University of St Andrews Scotland
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2021
• Subjects: acoustic surveys; Aptenodytes patagonicus; diving behaviour; foraging habitat; king penguin; prey distribution; Southern Ocean; South Georgia; [SDE]Environmental Sciences; Austral; Sandwich Islands; South Sandwich Islands; Icefish; King Penguins
• Online Access: https://hal.archives-ouvertes.fr/hal-03460885; https://doi.org/10.3389/fmars.2021.745200

International audience King penguins (Aptenodytes patagonicus) are an iconic Southern Ocean species, butthe prey distributions that underpin their at-sea foraging tracks and diving behaviourremain unclear. We conducted simultaneous acoustic surveys off South Georgia andtracking of king penguins breeding ashore there in Austral summer 2017 to gain insightinto habitat use and foraging behaviour. Acoustic surveys revealed ubiquitous deepscattering layers (DSLs; acoustically detected layers of fish and other micronekton thatinhabit the mesopelagic zone) at c. 500 m and shallower ephemeral fish schools. Basedon DNA extracted from penguin faecal samples, these schools were likely comprised oflanternfish (an important component of king penguin diets), icefish (Channichthyidaespp.) and painted noties (Lepidonotothen larseni). Penguins did not dive as deepas DSLs, but their prey-encounter depth-distributions, as revealed by biologging,overlapped at fine scale (10s of m) with depths of acoustically detected fish schools.We used neural networks to predict local scale (10 km) fish echo intensity and depthdistribution at penguin dive locations based on environmental correlates, and developedmodels of habitat use. Habitat modelling revealed that king penguins preferentiallyforaged at locations predicted to have shallow and dense (high acoustic energy) fishschools associated with shallow and dense DSLs. These associations could be used topredict the distribution of king penguins from other colonies at South Georgia for whichno tracking data are available, and to identify areas of potential ecological significancewithin the South Georgia and the South Sandwich Islands marine protected area.