That extra X chromosome means a female can receive both a black and orange color gene, which gives rise to calico and tortoiseshell variations. Stephanie Karpf, a veterinarian at For Cats Only in West Palm Beach, Florida. “For a cat to be a calico, it must have two X chromosomes, and typically only female cats have two X chromosomes, says Dr. This can be chalked up to the female’s extra X chromosome. According to Bell, research shows that fewer than 1 in 1,000 calico cats are male. Illustration: Josh Carter Are All Calico Cats Female?Ĭalico cats have the same coloration as tortoiseshell ones, white orange and black blended together, but calicos have distinctly-marked patterns. If the mother cat is tortoiseshell and the father cat is orange, half of the female kittens will be orange, she says. To get an orange female kitten, both the mother and father must be orange, Konecny says. What does this all mean for their offspring? If a mother cat is orange, her male kittens will be orange regardless of their father’s color, Konecny says, and if a mother cat is tortoiseshell (a mix of black, white and orange), half of her male kittens will be orange while the other half will be black. This makes male orange cats more frequent than orange females,” Bell says. “As the frequency of the orange gene is much less than the frequency of the black gene in the general cat population, the chance of having two orange genes is much less frequent.

While female cats will inherit an orange coat only if they carry the orange gene on both X chromosomes, if a male carries the orange gene at all, he will be orange, says Konecny. More: 300+ Unique, Cute & Funny Cat Names Are All Orange Cats Male?Ībout 81 percent of orange cats are male, says Bell. The female’s extra X chromosome allows the possibility of her receiving both a black and orange gene, says Bell. Therefore, males can be black or orange (or other color variations based on other gene locations) but cannot have both black and orange hair colors on their body. Males normally carry only one X chromosome. Susan Konecny, medical director for Best Friends Animal Society in Kanab, Utah. This allele is ‘recessive’ and allows for expression of a non-orange (usually black) coloration,” says Dr. The other allele will create a non-orange coloration. This allele will cover up all other colors, except pure white. “One allele will create orange coloration. So an X chromosome can contain either a black hair gene or an orange hair gene, but not both. “They are actually alleles, meaning they are two variations of the same gene in one location on the chromosome,” he says. Jerold Bell, adjunct professor of genetics at Cummings School of Veterinary Medicine at Tufts University in North Grafton, Massachusetts. This is the same chromosome that, along with Y in males, determine a cat’s sex, says Dr. The color genes for black and red in cats are contained within the X chromosome. And red, which is determined by the orange gene, can become cream.

These colors can mutate into different shades-black can become chocolate, cinnamon, lilac, blue and fawn. Whether calico, tortoiseshell, orange, black, brown, or gray, a cat’s fur color is derived from two dominant colors: Black and red. A small percentage of orange cats are female, and even a more miniscule portion of calico cats are male.īelow, learn how genetics and sex influences a cat’s coat color, and why some cats don’t fit typical color patterns. Nature doesn’t always abide by a rigid set of rules, however, including when it comes to feline fur color. Thus, no color is associated with a particular sex, except in cats and hamsters.” “Since the genes for sex and hair colors are on different chromosomes, they are inherited independently of each other. “These other chromosomes contain genes that affect hair color, pattern, shape and length,” Grahn says. Robert Grahn, a forensic analyst at the veterinary genetics laboratory at the University of California in Davis. But a number of additional chromosomes are present and vary depending upon species, says Dr. As you may recall from high school biology, mammals have two chromosomes that determine their sex-XX for females and XY for males. The color of a cat’s coat is closely linked to its gender. Most orange cats are male and most calicos are female. And you’re certain that the orange tabby cat you want to adopt at the cat shelter is a boy. You’ve always assumed the calico cat that sits in your neighbor’s window is a she.

Orange tabby cats