My favorite guide to understanding cats and their origins says that the Ginger (Tabby) Orange Cats are predominately male, and only one female is born for every three male Tabby Cats.  They say that this happens because female cats have two XX chromosomes, and male cats have an X and Y chromosome. The orange color or dominant trait, comes from the parent cat’s X chromosome, so since the females have two XX’s already, only the male inherits that color most of the time.  It is a rarity but both the male and female tabby cats are equally loving and friendly, and make excellent pets.