Defining animal residency and migration routes and variation in timing of movements consequently is essential to accurately delineate core space use for wildlife management. While population-level movement may appear predictable, certain species can show variability in migration timing among individuals and across years as a result of the dynamic environment they inhabit and their individual physiological needs ( Brodersen et al., 2012 Fraser et al., 2019 Bauer et al., 2020). Migrations between distant residency regions commonly occur in response to maintaining optimal thermal envelopes ( Kessel et al., 2014 Payne et al., 2016, 2018), but are often associated with seeking out highly productive areas (i.e., high prey availability) (e.g., Jorgensen et al., 2010 Barnett et al., 2011) and areas for reproduction ( Chapman et al., 2015). For highly mobile species, horizontal movement patterns can be predictable, composed of residency areas connected by migration corridors, with population-level movements in response to regional biotic and abiotic drivers ( Bowlin et al., 2010 Shaw, 2016). The movements of individual animals over time and space have profound impacts on animal ecology at all levels from the individual to the ecosystem ( Nathan et al., 2008 Earl and Zollner, 2017). Our findings expand knowledge of the movements and migration of the WNA white shark population and comprise critically important information to inform sound management strategies for the species. These results demonstrate the value of using multiple tag types to track long-term movements of large mobile species. Overall, results show dynamic inter- and intra-annual three-dimensional patterns of movements conserved within discrete phases. White sharks monitored with pop-up satellite-linked archival tags made extensive use of the water column (0–872 m) and experienced a broad range of temperatures (−0.9 – 30.5☌), with evidence for differential vertical use based on migration and residency phases. While broad residency and migration periods were consistent, migratory timing varied among years and among individuals within years. An autumn/winter migration occurred with sharks moving rapidly south to overwintering residency areas in the southeastern United States Atlantic and Gulf of Mexico, where they remained until the following spring/summer. Summer residency areas included coastal Massachusetts and portions of Atlantic Canada, with individuals showing fidelity to specific regions over multiple years. Moreover, increased off-shelf use occurred with body size even though migration and residency phases were conserved. While most sharks undertook an annual migratory cycle with the majority of time spent over the continental shelf, some individuals, particularly adult females, made extensive forays into the open ocean as far east as beyond the Mid-Atlantic Ridge. Overall, WNA white sharks showed repeatable and predictable patterns in horizontal movements, although there was variation in these movements related to sex and size. To address this need, we tracked 48 large juvenile to adult white sharks between 20, using a combination of satellite-linked and acoustic telemetry. For the white shark ( Carcharodon carcharias), detailed movement and migration information over ontogeny, including inter- and intra-annual variation in timing of movement phases, is largely unknown in the western North Atlantic (WNA), a relatively understudied area for this species. Combining tracking technologies can yield powerful datasets over multiple spatio-temporal scales to provide critical information for these purposes. Understanding how mobile, marine predators use three-dimensional space over time is central to inform management and conservation actions. 6Disney’s Animals, Science, and Environment, Bay Lake, FL, United States. 5Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA, United States.4School of Aquatic and Fisheries Sciences, University of Washington, Seattle, WA, United States. 3Integrative Biology, University of Windsor, Windsor, ON, Canada.2Center for Shark Research, Mote Marine Laboratory, Sarasota, FL, United States.1Marine Science Research Institute, Department of Biology & Marine Science, Jacksonville University, Jacksonville, FL, United States.
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