. The Canadian field-naturalist. Canada Alaska Polar Bear Sightings, Survey Track /'â ./ Bering Sea. âT im -=c 155* 19:i- -145' 400 â1- 1«i 400 Miles â 130* -65* Figure 2. Study are with survey tracks and Polar Bear sightings. tion. Position updates, sighting locations, and ice- coverage data were recorded on an onboard comput- er system connected to a Global Positioning System receiver in the aircraft. These records included infor- mation on numbers of Polar Bears per sighting and ice cover within about 1-2 kilometers of the aircraft. Polar Bear tracks and kill sites also were recorded dur-
. The Canadian field-naturalist. Canada Alaska Polar Bear Sightings, Survey Track /'â ./ Bering Sea. âT im -=c 155* 19:i- -145' 400 â1- 1«i 400 Miles â 130* -65* Figure 2. Study are with survey tracks and Polar Bear sightings. tion. Position updates, sighting locations, and ice- coverage data were recorded on an onboard comput- er system connected to a Global Positioning System receiver in the aircraft. These records included infor- mation on numbers of Polar Bears per sighting and ice cover within about 1-2 kilometers of the aircraft. Polar Bear tracks and kill sites also were recorded dur- ing September and October from 1987 through 1999. Survey effort in the Beaufort Sea focused primarily along the coast, continental shelf, and shelf break, while surveys in the northern Bering and eastern Chukchi seas extended from the coast to the International Date Line (Figure 2). The Polar Bear sightings, kill sites, locations of bear tracks, and ice-coverage data were converted into database files and analyzed with Arcview Geo- graphic Information System Program (devel- oped by ESRI in Redland, Calif.). Tables and graphs were created in Microsoft Word and Microsoft Excel (Windows 2000) to compare bear numbers and sight- ings with ice coverage (Table 1 and Figure 3) and kill sites and bear tracks with ice cover (Figures 4 and 5). The number of bear sightings and the survey effort (kilometers flown) were plotted by ice category to com- pare ice-cover use (Figure 2). This analysis is provid- ing useful information on habitat use by Polar Bears occurring in Alaskan waters. Results and Discussion Table 1 shows the number of Polar Bears and num- ber of sightings recorded offshore by ice cover and on the mainland or on barrier islands. Figure 4 shows the number of Polar Bear kill sites and ice coverage recorded at the kill locations. Figure 5 shows the num- bers of Polar Bear tracks recorded and ice coverage at their locations. Over the 20-year period and the 1 096 620
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