Sometimes people talk about tortoiseshell cats, also known as “calicos” or “torties," as if they’re a specific breed; but the truth is, they’re not. These cats have distinctive multicoloured coats, mostly a combination of black and orange (usually mixed together closely, but sometimes occurring as large separated patches) with white. Other colour varieties can include dark brown, red, and cream. These colour patterns appear in some breeds as an accepted variety, and are common in well-known breeds like the Japanese Bobtail and the Cornish Rex.
Coat colour genetics in cats is complex, and the expression of some colours is linked to biological sex. Certain colour combinations, such as that of the tricolour tortoiseshell, are only possible in female cats. Because orange is linked to the X chromosome, only female cats (XX) are able to express both black and orange, while males can express just one of the two. However, there are some male tortoiseshell cats: those born with two X chromosomes and one Y chromosome (XXY, called Klinefelter syndrome in humans), which are almost always infertile.
Tortoiseshell cats often have unpredictable personalities, but in general they’re affectionate and very attached to their owners. They also tend to be highly territorial and rarely allow intruders in their homes. They’re curious creatures that need plenty of activity and entertainment, making controlled access to the outdoors and an enriching environment ideal. These cats are associated with many myths and legends, and star in countless stories of all kinds.
Have you ever seen a tortoiseshell cat?