Estimates of polar bear abundance for different regions and assumptions about g(0) in Russian survey flights, along with 95% log-based confidence intervals.

Regions include the full study grid (‘Chukchi’), mean (i.e., time-averaged) abundance for those cells of the survey grid with centroids in U.S. waters (‘U.S.’), mean abundance in Russian waters (‘Russia’), mean abundance in the portions of our study area that overlapped the polar bear specialist group boundary (‘PBSG’), and an estimate for the area used for capture and release of bears in a mark-recapture study of polar bears in the Chukchi Sea (‘Regehr’ [8]). For a map of the study area and related regions, see Fig 1).