Model fitted and you will diagnostics
We fit our Bayesian state-space model, consisting of both movement and observation process components, using Markov chain Monte Carlo (MCMC) methods. We assigned uninformative priors whenever there were no a priori expectations about the relationships of the model parameters and the movement behavior states (see Appendix S1). n,t) within each iteration of the MCMC algorithm (see Appendix S2). We initialized six chains from random starting values drawn from the prior distributions. After initial pilot tuning and burn-in, we ran the chains until the univariate Gelman–Rubin potential scale reduction factor (PSRF) for monitored parameters was <1.2 and effective sample sizes exceeded 4000. This required about 6 million iterations per chain, where 1 million iterations for each parallel chain required about 100 h using six cores of a 3.7-GHz processor. Data and code can be found in Data S1.
Abilities
Considering rear modes getting state tasks, we receive these bearded seals spent 70% of their implementation periods on the benthic foraging condition (B). They hauled out on ice (state We) and you will rested in the ocean (county S) within the roughly equal size, however, discover an obvious seasonal component for the interest budgets one of the latest hauled on frost (I), benthic foraging (B), and transit (T) claims you to definitely coincided towards the summer haven and you can cold temperatures improve out-of water frost from the Snowy (Table 2). The seals showed extreme benthic foraging along side continental shelves 
away from the Chukchi otherwise Beaufort seas due to the fact sea freeze receded northward inside summer time. We discover almost no proof such freeze-related seals hauling out on property, no matter if close to the shore in mainly ice-100 % free months during the summer. Remarkably, a grown-up men briefly moved northern of Beaufort seaside bookshelf inside late and you can are predict getting hauled out on the fresh new receding sea frost boundary between bouts away from middle-h2o foraging about higher seas of one’s Canada Basin (Fig. 2). We offer reveal cartoon out of predicted actions and you may county assignments for everyone seals according to bathymetry and you can water freeze safety from inside the Appendix S3.
- There had been seasonal variations in craft finances anywhere between “summer” (away from tagging within the later Summer and you will early July to help you 29 Sep), “autumn” (step one Oct to 29 December), and you may “winter” (step 1 January until tag losses between February and you can April) that coincided to the southern area advance regarding cold weather sea ice during the this new Arctic. Passion funds descriptions was indeed calculated according to research by the posterior means regarding time invested in for each condition that have down (LCI) and you may top (UCI) credible durations predicated on 95% high posterior thickness. Personal secure craft costs are part of Appendix S4.
As expected, the resting states (I, S, and L) exhibited shorter step lengths, no directional persistence, and lower proportions of each time step diving >4 m below the surface based on state-specific parameter estimates (Fig. 3; see Appendix S4 for posterior sumeters). Both the mid-water foraging (M) and transit (T) states exhibited longer step lengths, lower proportions of dry time, and higher proportions of diving >4 m below the surface. Only the transit state exhibited strong directional persistence, but state M exhibited moderate directional persistence for some individuals (Fig. 3). The benthic foraging (B) state generally exhibited moderate step lengths, no directional persistence, lower proportions of dry time, higher proportions of diving >4 m below the surface, and considerably higher benthic dive counts (posterior median for ?B = 41.4; 95% highest posterior density interval: 41.2–41.7). The resting (?I = ?S = ?L = 9.7; 95% HPDI: 9.4–10.0) and transit (?T = 15.0; 95% HPDI: 14.5–15.5) states exhibited moderate benthic dive counts, while the mid-water foraging state generally had the lowest benthic dive counts (?M = 1.5; 95% HPDI: 1.3–1.7; Fig. 3). The moderate benthic dive counts for the resting and transit states could be attributable to mid-interval state switches, but there certainly could have been opportunistic benthic foraging during transit. There also could have been high-speed, directionally persistent benthic dives while transiting in relatively shallow shelf waters.