Calico cats are easy to recognize with their tricolor coats but they aren’t actually a breed. It’s a color pattern that appears due to genetics and isn’t found from some breeds. Calicos differ from tortoiseshell cats due to the large amounts of white that appear on the body and patchy markings as opposed to the splatter paint design that tortoiseshell cats tend to have. Some calicos may even have a swirl pattern on the sides of their stomach.
Calico cats are almost always female, in fact, it’s extremely rare to find a male calico. This is due to genetics and the X chromosome that determines the color of a cat. Female cats have two X chromosomes and male cats have an X and a Y. The Y chromosome does not carry the color gene leaving little to no chance of a calico pattern. However, some male cats may have an XXY abnormality which could result in a calico patterned male.
Female cats can have a gene for an orange coat on one X chromosome and the gene for black or white on the other X chromosome. The chromosomes affect each other and create a blotchy pattern on fur. Calico cats can also have variations to how dark or muted the colors are. A diluted calico coat is commonly referred to as “pastel” and the fur has a cream or diluted look to it.
Throughout history calico cats have been written about, acknowledged, and even believed to be magical. In Japan, a calico cat was considered a good luck and sailors would adopt the cat to protect them on their long journeys at sea. In 2001, the state of Maryland adopted the calico cat as their state cat because of the pattern of black, white, and orange which are the same colors as their baseball team, the Baltimore Oriole, and the Baltimore Checkerspot butterfly.