Data Supporting Walrus Areas of Use in the Chukchi Sea During Sparse Sea Ice Cover

The dataset consists of geospatial files depicting the estimated June-to-November distribution of walrus foraging and occupancy during a four year period of sparse sea ice cover above the Chukchi Sea continental shelf (2008-2011). The walrus distribution and utilization estimates are based on location data from satellite-linked radio-tracked walruses in the Chukchi Sea (2008-2011). Compared to previous years this period was marked by earlier and more extensive sea ice retreat (June - September) and delayed sea ice freeze-up (October - November). This allowed walruses to arrive earlier, occupy slightly more northern areas, and stay later in the Chukchi Sea than previously. Data are combined for all four years and structured by month (June [06] - November [11]). Within each month, we estimated walrus utilization distributions by using an unweighted movement based kernel density estimator. The kernel density was then weighted by the amount of time walruses spent foraging during each recorded track segment. We present contours of the kernel density ranging from the 10th to 95th percentile.