Design suitable and you can 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). _letter,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

According to posterior modes to possess county tasks, we found these bearded seals invested 70% of their deployment periods from the benthic foraging county (B). They hauled on ice (state We) and rested at sea (county S) when you look at the around equal size, but there’s a definite regular component from inside the activity budgets certainly one of the fresh new hauled from freeze (I), benthic foraging (B), and you will transportation (T) states one to coincided to the summer sanctuary and you will winter advance off water frost on Snowy (Dining table 2). All the seals exhibited extreme benthic foraging over the continental cupboards of the new Chukchi or Beaufort oceans once the ocean ice receded northward in the summer months. We found hardly any evidence of this type of frost-related seals hauling out on home, even if around the shore for the mostly ice-totally free period in the summertime. Amazingly, an adult male briefly gone north of the Beaufort coastal bookshelf inside later and try predict to have hauled from the receding ocean frost edge between bouts out of mid-liquids foraging regarding better oceans of the Canada Basin (Fig. 2). You can expect a detailed animation of forecast movements and you may county projects for everybody seals relative to bathymetry and you will water ice safety inside Appendix S3.

• There have been regular variations in interest spending plans between “summer” (away from marking during the late Summer and you can very early July in order to 29 September), “autumn” (1 Oct so you can 30 December), and you will “winter” (step one January up until mark losings ranging from February and April) one to coincided towards the southern progress of cold temperatures sea ice when you look at the the brand new Cold. Activity budget summaries was indeed computed in line with the posterior mode regarding date spent in each county which have all the way down (LCI) and top (UCI) legitimate periods based on 95% high posterior density. Individual close pastime costs are included in 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 Toledo hookup tips = 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.