Polar Bear Ice Ursus maritimus Ursidae POBE URSMAR Mammal Predator Behavior dangerous fur white cold snow global warming pack ice drift floe threatened melting melt arctic Arctic Zone North Pole polar region marine sea landscape icescape behavior symbol symbolic allegorical emblematic thoughtful thought-provoking alarming worrying concerning two fighting fight battle territory aggressive attack Svalbard Norway December Summer Spitsbergen snowy paw vulnerable endangered pole iceberg danger water wild nature frozen climate-change climate funny love play playing mate mating season male female paired couple summer Rhine-Westphalia wrangle wrangling struggle struggling quarrel guarelling Europe pale pile stake Spitzbergen copulation