The silver fox is a melanistic form of red fox. Melanism is when the animal's coloring is much darker than normal. Interestingly, fox squirrels, who have brownish body fur and reddish tummy fur also have a melanistic form that resembles this. I had a "black" fox squirrel that I hand raised. He lived to be 12 years old, a full ten years longer than he would have in the wild.
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"Fox Squirrel" [Scientific name - *Sciurus niger.* Sciurus is Greek for “shade tail” & niger is Latin for “dark.” Fox squirrels are noticeably bigger than gray squirrels and can have a variety of fur colors depending on their location.They can have a white belly & a face with black and white patches. In some areas they are also called the monkey-faced squirrel or raccoon squirrel due to their facial markings.]~[Photographer Sam Bland]