Calico cats are domestic cats that are comprised of a garden of cat colors, either vibrant orange (technically known as "red"), white and black, or more subdued flaxen, blue-gray, and white. In feline genetics, the latter is known as "dilute calico." The various patterns of the calico patches are almost as ubiquitous as snowflakes. You'll never see two exactly alike.
Calicoes are almost all female, and the rare male is always sterile. (So much for the hopes of those thinking of breeding a rare line of cats.)
Calico Cats Are the Most Colorful Cats
Calicoes are rivaled only by tortoiseshell cats, who are genetically very similar. Indeed, it is often difficult to tell if an individual cat is a calico or a "tortie with white," The most common difference is that tortoiseshell colors (red and black) are interwoven throughout the coat, where calico cats have distinctive patches of solid color. Sometimes the distinction is even more blurred, when a calico may have some woven patches intermingled with the solid areas, as depicted in the first photo. Such cats are often called "calitorts"...or could they be "torticals?"
Calicoes share that personality trait of tortoiseshell cats commonly described as "tortitude." They are sassy, spunky and very independent. On the other hand, calicoes are sweet, loving, and loyal cats. If you hunger for unconditional love, a calico cat will willingly and enthusiastically fulfill that need.
Cat Breeds Embracing Calico Cats
It would be easier to give a list of those breeds which do not accept calicoes than those that do. Calicoes are not allowed in pointed breeds, such as the Siamese or Himalayan, nor those which allow only solid colors, such as the Bombay, the Russian Blue and the British Shorthair. You'll find colorful calico cats in the Persian, Manx, Maine Coon, and Scottish Fold breeds, to name a few. Some breed standards even allow tabby patches in their calicoes. Calico is the most popular color pattern in Japanese Bobtails.
Researchers began seriously studying calico cats in the 1940s. Murray Barr and his graduate student E.G. Bertram noticed dark, drumstick-shaped masses inside the nuclei of nerve cells of female cats, but not in male cats. These dark masses eventually were called Barr bodies. In 1959, Japanese cell biologist Susumu Ohno determined the Barr bodies were X chromosomes. In 1961, Mary Lyon proposed the concept of X-inactivation: one of the two X chromosomes inside a female mammal shuts off. She observed this in the coat color patterns in mice.
Calico Cat Fame
A popular children's poem, written by Eugene Fields in the late 1800s, called "The Duel," featured "the gingham pup and the calico cat." In modern days, the State of Maryland officially named the calico cat as its "State Cat," in October of 2001. The calico shares the colors of Marylands State Bird, the Baltimore oriole and its State Insect, the Baltimore Checkerspot butterfly.
Calico cats are believed to bring good luck in the folklore of many cultures. In the United States, these are sometimes referred to as money cats. In Japan, the Maneki-Neko figures depict Calico cats, bringing good luck.