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 symbol symbolic allegorical emblematic thoughtful thought-provoking alarming worrying concerning solitude lonely solitary loner snowy paw hunter vulnerable endangered pole iceberg danger water wild nature frozen climate-change climate sky wonderful scenic Canada July summer beautiful blue Rhine-Westphalia pale pile stake