It looks like our Red Squirrels have finally finished their fall molt. Their namesake color appears only on the tails of their thicker gray winterwear.
These little squirrels will molt again in the spring and gradually return to their greatly variable reddish-orange-brown colors by summer. Their bellies will remain white or cream-colored all year, however. The image above of one of our now-gray neighbors was taken on Tuesday (December 10), while the image below of the then-reddish one was taken in August:
As with many other winter-foraging mammals, the coats of Red Squirrels have insulating double layers. Longer and thicker guard hairs on the outside protect against the severities of the winter environment, especially water, wet snow, and wind; short and thin hairs on the inside trap air between the two layers, where it warms. (Brooklin, Maine)