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 symbol symbolic allegorical emblematic sad thoughtful thought-provoking alarming worrying concerning Svalbard lying horizon impressing solitude lonely solitary animal loner paws paw print tracks traces back view Norway July Summer Spitsbergen summer Rhine-Westphalia Europe pale pile pole stake animals Spitzbergen