Male Tortoiseshell Cats
Most males can only have the red gene or the non-red gene, but not both. The resulting product is a solid red tabby or a solid black cat, rather than the combination of the two that comprises the tortoiseshell pattern. However, as mentioned earlier, not all Tortoiseshells are female. This occurrence is made possible by the fact that some males have two X chromosomes and one Y chromosome (XXY).