1. Amstrup SC (2003) Polar bear, Ursus maritimus. In: Feldhamer GA, Thompson BC, Chapman JA (eds) Wild mammals of North America: biology, management, and conservation, 2nd edn. Johns Hopkins University Press, Baltimore, pp 587–610
2. Blix AS, Lentfer JW (1979) Modes of thermal protection in polar bear cubs—at birth and on emergence from the den. Am J Physiol 236:67–76
3. Blix AS, Steen JB (1979) Temperature regulation in newborn polar homeotherms. Physiol Rev 59:285–304
4. Brown G (1993) The great bear Almanac. Lyons & Burford Publ, New York
5. Gill AE (1982) Atmosphere–ocean dynamics. International Geophysics series, vol 30. Academic Press, San Diego