Summary: | The distribution and movement of the polar bear ( Ursus maritimus) are discussed. Polar bears are distributed in the Arctic Region, and currently, there are believed to be 19 subpopulations ( 14 of which occur in or are shared with Canada). Overall, population numbers are estimated at 22,000 to 27,000 with a possible range of 20,000 to 40,000 individuals. Distribution is a result of the bears' fidelity to specific areas and their movements within and between certain regions (resulting in a general home range). Factors that affect the bears' movements (and their resulting home range and distribution) include ice coverage, food availability, and feeding, breeding, and denning activities; patterns often emerge as a result of these factors. Study methods that are used are mark and recapture, aerial surveys, and remote sensing techniques (radio and satellite tracking). Information from remote sensing studies and the techniques used to obtain it can be applied to all polar bear populations. Geographic Information Systems (GIS) are becoming extremely important tools in analyzing study data, especially in relation to distribution, home range, movement, and fidelity. These aspects are now being studied in more detail due to the availability of better and more convenient study methods (such as satellite tracking) and analysis tools (such as GIS) than were available in previous decades. Hence, by knowing where bears go, when (and possibly why) they go there, and how long they stay in those areas, researchers and managers can form a basis for future reference when they need to make decisions regarding the population in question or the species itself. Management issues are also discussed in relation to the past, present, and future. The International Agreement on the Conservation of Polar Bears and Their Habitat (1973), the Marine Mammal Protection Act (1972), and other local, national, and international management plans have resulted in voluminous research and much cooperation in order to foster the survival of this species. Thus, the polar bear's success story will continue and can become a model for the management of other species.
|