Originally Gray Squirrels were black in Canada and in other northern parts of their range. Fox Squirrels have a similar range, but they are more often black in the southern United States. In much of their range, especially in western regions, black squirrels are most common where either Fox or Gray squirrels have been introduced. Apparently black squirrels were often introduced because they seemed more exotic than “normal” squirrels. Nature.com gives two examples. Black Squirrels in Kent, Ohio, were introduced from Canada in the 1950s. Marysville, Kansas, black squirrels escaped from a carnival in the 1920s.