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.
The Red Fox: Males are referred to as reynards, females as vixens, and young as kits, pups or cubs. A group of foxes is a "skulk", "troop" or "earth". Their main diet is insects, reptiles, berrys and nuts. They, like squirrels, are hoarders. They gather, eat just enough for the day, and then store the rest for snow days.