How do seabirds modify their search behaviour when encountering fishing boats?

• Published in: PLOS ONE
• Main Authors: Corbeau, Alexandre, Collet, Julien, Fontenille, Melissa, Weimerskirch, Henri
• Other Authors: Centre d'Études Biologiques de Chizé - UMR 7372 (CEBC), Institut National de la Recherche Agronomique (INRA)-La Rochelle Université (ULR)-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2019
• Subjects: [SDE]Environmental Sciences; Patagonian Toothfish
• Online Access: https://hal.science/hal-02301452; https://doi.org/10.1371/journal.pone.0222615

International audience Seabirds are well known to be attracted by fishing boats to forage on offal and baits. Weused recently developed loggers that record accurate GPS position and detect the presenceof boats through their radar emissions to examine how albatrosses use Area RestrictedSearch (ARS) and if so, have specific ARS behaviours, when attending boats. As much as78.5% of locations with a radar detection (contact with boat) during a trip occurred withinARS: 36.8% of all large-scale ARS (n = 212) and 14.7% of all small-scale ARS (n = 1476)were associated with the presence of a boat. During small-scale ARS, birds spent moretime and had greater sinuosity during boat-associated ARS compared with other ARS thatwe considered natural. For, small-scale ARS associated with boats, those performed overshelves were longer in duration, had greater sinuosity, and birds spent more time sitting onwater compared with oceanic ARS associated with boats. We also found that the proportionof small-scale ARS tend to be more frequently nested in larger-scale ARS was higher forbirds associated with boats and that ARS behaviour differed between oceanic (tuna fisheries)and shelf-edge (mainly Patagonian toothfish fisheries) habitats. We suggest that, inseabird species attracted by boats, a significant amount of ARS behaviours are associatedwith boats, and that it is important to be able to separate ARS behaviours associated toboats from natural searching behaviours. Our study suggest that studying ARS characteristicsshould help attribute specific behaviours associated to the presence of boats and understandassociated risks between fisheries.