Question: why are arctic foxes white in the winter

title: Arctic fox
text: The Arctic fox lives in some of the most frigid extremes on the planet , but they do not start to shiver until the temperature drops to − 70 ° C ( − 94 ° F ) . Among its adaptations for survival in the cold is its dense , multilayered pelage , which provides excellent insulation . Additionally , the Arctic fox is the only canid whose foot pads are covered in fur . There are two genetically distinct coat color morphs : white and blue . In the winter the white morph is white in color and turns brown along the back with light grey around the abdomen in summer . The blue morph is often a dark blue , brown , or grey color year - round . Although the blue allele is dominant over the white allele , 99 % of the Arctic fox population is the white morph . The fur of the Arctic fox provides the best insulation of any mammal .