Calico cats are uniquely beautiful felines, with a striking tri-color coat usually made up of white, black, and orange or red. Calico refers to a color pattern, though, not a breed, and it can occur in many breeds as a part of their breed standard coloring, including the American Shorthair, Maine Coon, Persian, Manx, and British Shorthair.
Calico cats are well known for being almost exclusively female, but is this based in fact or just another widespread myth? It turns out that this is 100% true! Except under rare genetic conditions, Calico cats are almost always female. There are fascinating reasons for this, which we detail here.
What Is a Calico Cat?
Calico is a unique color patterning and not a breed, though it is often mistaken as such. A calico cat is defined by having three separate, distinct colors in their coat: typically white, black, and red or orange. A cat with three colors but lacking white is defined as a tortoiseshell cat, and this coloration is often confused with calicos. White is typically the most prevalent color, usually making up about 75% overall, but this can vary too. There are also “dilute” calicos, consisting of coloring that is primarily white but with small patches of color.
Calico cats were named after the calico cloth that was first imported into the United States in the 1970s, with a similar tri-color pattern.
Why Are Calico Cats Almost Always Female?
Calico color patterning is not limited to any specific breed but can occur in any cat breed that has a range of color possibilities. Theoretically, male calico cats are almost impossible, and the same goes with tortoiseshell patterning. Male cats have XY sex chromosomes, and females have XX chromosomes, and X chromosomes carry the genes that determine coat colors. The X chromosome carries the gene for the orange and black colors in a calico’s coat, and since females have XX chromosomes, they can inherit one code for either, an impossibility in the XY chromosomes of males.
Since males can only have one X chromosome that will code for either black or orange and a Y chromosome with no color coding at all, the chances of a calico male are well near impossible. In fact, 99.9% of all calico cats are females.
Are There Ever Male Calico Cats?
So, if male calico cats are technically impossible, how is it that around 1 in 3,000 calicos is male? There is a genetic anomaly that can rarely occur in male cats, called Klinefelter’s Syndrome, a condition that can occur in humans too. This is characterized by a male cat inheriting an extra X chromosome from their mother or father, resulting in an XXY genetic makeup. The condition is not inherited but is instead a random genetic error that occurs after conception.
These male calicos are almost always sterile and cannot be used to breed more calico patterns. They are also less healthy than female calicos. They often have calcium issues resulting in weakened bone structure, cognitive and developmental issues, and increased body fat.
Calico cats are almost always females, with roughly 99.9% of all calico cats being female. Of course, in nature, there are always anomalies, and around one in every 3,000 calicos are male, but this is extremely rare. Male calicos are typically sterile and suffer from far more health issues than female calicos.
Featured Image Credit: Karen Kaspar, Shutterstock