Satellite Radio Tracking of Polar Bears Instrumented in Alaska

The NIMBUS 6 satellite system successfully tracked three instrumented polar bears for 8, 20, and 390 days as these bears traveled distances exceeding 330, 500, and 1650 km, respectively, from their release sites on the arctic ice north of Barrow, Alaska. Electronic equipment developed under U.S. Fish and Wildlife Service funding by commercial companies was designed as a 5 kg collar-shaped instrument package of appropriate dimensions to fit 180 to 250 kg polar bears. The primary biological objective of locating a pregnant bear in a den site was not achieved because the instrumented bear traveled off the shore of the Soviet Union, into an area not accessible to U.S. scientists.