Spatiotemporal analyses of tracking data reveal fine-scale, daily cycles in seabird–fisheries interactions

10 pages, 4 figures, 1 table.-- Data was generated within the frame of LIFE+ Project INDEMARES. Data are available at the following address: http://seabirdtracking.org/mapper/?dataset_id=874. Please contact specifically J. M. Arcos. SEO/BirdLife (jmarcos@seo.org)Human fisheries provide scavengers with abundant and predictable feeding opportunities that may schedule their behavioural patterns. Using miniaturized global positioning system (GPS) tracking technology, we evaluated how Audouin’s gull (Ichthyaetus audouinii), a Mediterranean endemic seabird that makes extensive use of feeding opportunities provided by fisheries, co-occurred (i.e. presumably interacted) with the most important fishing fleets operating off the NE Iberian Peninsula (i.e. diurnal trawlers and nocturnal purse seiners), both in space and time. Results showed that individuals were able to adapt their distribution and activity patterns to the scheduled routines of these fisheries. Waveform analyses based on co-occurring positions revealed that most interactions with trawlers occurred during the afternoon (16:00 h GMT + 1) when discarding occurs as vessels return to port. In contrast, gull-purse seiner interactions largely occurred at night (between 02:00 and 04:00 h) coinciding with the setting and hauling of the nets. Moreover, we found an individual component in seabird–fishery interactions, showing that there may be differential use of fisheries by individuals within the population. In addition to implications for our understanding of the behavioural ecology of this species, these results may have important management implications, particularly under the current European Union Common Fisheries Policy scenario of largely restricting discardsWith the funding support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S), of the Spanish Research Agency (AEI)This research was funded by the Spanish “Ministerio de Economía, Industria y Competitividad” (MEIyC; CGL2016-08963-R) and LIFE+ INDEMARES (LIFE 07NAT/E/00732). JO-C was supported by a Department Collaboration (18CO1/006033) from the Spanish "Miniterio de Educación y Formación Profesional". FR was funded by MEIyC “Subprograma Juan de la Cierva-Incorporación” (IJCI-2015-24531)Peer reviewe