. The Canadian field-naturalist. 100-80% 79-50% 49-25% 24-1% 0% Ranges of Ice Coverage Figure 3. Polar Bear sightings per kilometer recorded from April 1979 through October 1999 in the Beaufort, Chukchi and Bering Seas. Ice Coverages at Kill Sites. 100% 99-95% 94-90% 89-80% 79-70% 69-50% 49-40% 39-1% Percent Ice Coverage Figure 4. Number of kill sites and ice coveage recorded at each site. seas from 1979-1999 (Table 1). Of these bears, 784 were observed offshore at 400 sightings. Figure 2 shows the number of Polar Bears per kilometer of survey effort over ranges of ice coverage. The num- ber o
. The Canadian field-naturalist. 100-80% 79-50% 49-25% 24-1% 0% Ranges of Ice Coverage Figure 3. Polar Bear sightings per kilometer recorded from April 1979 through October 1999 in the Beaufort, Chukchi and Bering Seas. Ice Coverages at Kill Sites. 100% 99-95% 94-90% 89-80% 79-70% 69-50% 49-40% 39-1% Percent Ice Coverage Figure 4. Number of kill sites and ice coveage recorded at each site. seas from 1979-1999 (Table 1). Of these bears, 784 were observed offshore at 400 sightings. Figure 2 shows the number of Polar Bears per kilometer of survey effort over ranges of ice coverage. The num- ber of bears per kilometer increased substantially in >24% ice cover, with the highest number observed in 80-100% ice cover. These observations suggest that Polar Bears may use 80-100% ice cover more often than lower percentages of ice cover. This habitat use probably is related to the availability of seals, their pri- mary prey. Table 1 lists the number of bears and sight- ings seen offshore in other ice concentrations. Thirty- five kill sites and 769 Polar Bear track sightings were recorded, mostly in 80-100% ice cover (Figures 3 and 4, respectively). Tracks with zero ice cover were record- ed on land or barrier islands. A total of 328 bears (at 83 sightings) were recorded on the mainland or on barrier islands (Table 1). Most of these bears were associated with whale carcasses and bowhead whale subsistence harvest sites along the Beaufort Sea coast. The large numbers of bears were recorded on land in 1992 (67 bears) and 1998 (217 bears), when repeat sightings were made of sever- al bears feeding on whale carcasses along the Beau- fort Sea coast (Table 1). Studies of radio- and satellite-tagged Polar Bears have provided useful information on the movements and habitat use of individual Polar Bears (Arthur et al. 1996; Ferguson et al. 1998; Amstrup et al. 2001; Dumer et al. 2004). These studies recorded Polar Bear locations and compared them with satellite-derived,. Please note th
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