Here's why:
* Brindle as a coat pattern: Brindle is a less common coat pattern in Scottish Terriers compared to the more prevalent solid colors like black, wheat, and brindle.
* Black as a base color: While black is a common base color for Scottish Terriers, it's less common than the wheaten color.
* Combination: The combination of these two factors, black base coat and brindle pattern, makes the black brindle variety particularly uncommon.
It's important to note: While black brindles are rare, they are still recognized as a legitimate color variety by breed standards.
If you are interested in a black brindle Scottish Terrier, you may have to do some extra searching. You can try contacting breeders who specialize in the breed or reaching out to breed clubs for help in finding one.