Polar Bear Ice Ursus maritimus Ursidae POBE URSMAR Mammal Predator Behavior dangerous fur white cold snow global warming pack ice floe threatened melting melt arctic Arctic Zone North Pole polar region marine sea drift landscape icescape behavior walk walking symbol symbolic allegorical emblematic sad thoughtful thought-provoking alarming worrying concerning Svalbard horizon impressing solitude lonely solitary animal loner cloudy clouds sky distance habitat search-for-food Norway July Summer Spitsbergen summer Rhine-Westphalia Europe pale pile pole stake animals Spitzbergen