 Fur Trappers Association, North Bay, Ontario, Canada.↑ In unusually warm conditions, the hollow tubes provide an excellent home for algae. While the algae is harmless to the bears, it is often a worry to the zoos housing them, and affected animals are sometimes washed in a salt solution, or mild peroxide bleach to make the fur white again.↑ Derocher, Andrew E. (2005). "Sexual dimorphism of polar bears" (PDF). Journal of Mammalogy. 86 (5): 895–901. doi:10.1644/1545-1542(2005)86[895:SDOPB]2.0.CO;2. ISSN 1545-1542. JSTOR 4094434. 2011-01-10 දින මුල් පිටපත (PDF) වෙතින් සංරක්ෂණය කරන ලදී. සම්ප්‍රවේශය 2013-03-22. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)↑ 38.0 38.1 Rosing, pp. 20–23↑ 39.0 39.1 39.2 Stirling, Ian (1988). "behavior". Polar Bears. Ann Arbor: University of Michigan Press. ISBN 0-472-10100-5.↑ Polar Bears: VI. Behavior., SeaWorld. Retrieved 21 January 2011.↑ 41.0 41.1 41.2 Matthews, pp. 73–88↑ "Arctic Bears".   PBS Nature.  