Cats adorned with a blend of black, orange, and white fur are commonly referred to as “calico cats“. These felines are known for their friendly demeanor, their strong attachment to and loyalty towards their owners. The striking combination of three colors makes them truly stand out, and they boast the most diverse color palette among cats. While the majority of calico cats you encounter are females, the chance of encountering a male calico is a rare occurrence, with only a 0.3% probability. Unlike tortoiseshell cats, whose patterns are also randomly distributed, calico cats feature more distinct color block boundaries, with white often being the dominant hue, giving them a cows-like appearance.
1.The Legend of the Calico Cat.
In Japanese folklore, there is a tale about a calico cat: During the Edo period in the Yoshiwara red-light district, there was a courtesan named Usugumo. She adored cats and had a tricolor cat named “Tama”. They were inseparable, to the point where the cat would even follow her into the bathroom. Soon, rumors began to spread that cats could bewitch people, and it was said that Usugumo must have been possessed by the cat’s magic. The brothel owner, fearing that these rumors would tarnish Usugumo’s reputation, ordered her to abandon the cat. Usugumo refused, loving the cat as much as ever. One day, as the cat followed Usugumo into the bathroom, the brothel owner seized the opportunity and, while Usugumo was distracted, chopped off the cat’s head with a knife. To their shock, they discovered that the cat’s head was clamped tightly around a snake. It was then understood that the cat had been following Usugumo into the bathroom to protect her. Heartbroken, Usugumo sent the cat’s remains to a temple and erected a cat tomb in its honor.
2.Why Are Calico Cats Mostly Females?
Genetics identifies cat fur color inheritance as “sex-linked inheritance,” where the differently colored patches are the external manifestation of the cat’s DNA, determined by chromosomes.
A cat’s body cells contain 19 pairs of chromosomes (18 pairs of autosomes + 1 pair of sex chromosomes), with sex determination similar to humans: male cats have XY, and female cats have XX. Only the X chromosome can control one color, while the Y cannot. Actually, all cats are inherently white; the different colors and patterns appear due to carrying other pigment genes, or genes for white spots, albinism, etc. Calico cats may seem to have three colors, but in reality, they inherit two colors from their parents (black and orange) in addition to their inherent white. If both parents carry only one color, and it’s the same, the offspring will not have a calico pattern. But what if it’s a male orange cat (XY) + a female black cat (XX)? The offspring will be… Male cats (XY): black cats, blue cats (black diluted to gray). Note: Since the Y chromosome doesn’t contribute to color, all male offspring inherit the black color from their mother. Female cats (XX): calico cats/tortoiseshell cats, calico cream (orange diluted to cream). Note: With two X chromosomes, they inherit the orange from their father and the black from their mother, combined with their inherent white, resulting in the calico pattern.
Let’s swap the fur colors of the cats again: a male black cat (XY) + a female orange cat (XX). Male cats (XY): orange cats, cream cats.
PS: Since the Y chromosome doesn’t contribute to color, all male offspring inherit the orange color from their mother. Female cats (XX): calico cats/tortoiseshell cats, calico cream.
PS: With two X chromosomes, they inherit the black from their father and the orange from their mother, combined with their inherent white, resulting in the calico pattern.
Did you notice? Regardless of the combination, calico cats are always female! That’s because female cats have an extra “X” chromosome compared to male cats! But what if there’s genetic mutation or chromosomal abnormality? Then, extremely rare male calico cats can indeed appear.
3.Why Are Male Calico Cats Extremely Rare?
According to statistics from the Humane Society, male calico cats account for only three in ten thousand of all offspring produced, meaning the probability of their occurrence is 0.3%.
The genetic defect in male cats manifests as infertility, a condition known in human medicine as “Klinefelter Syndrome” (congenital testicular hypoplasia), which is a congenital disorder caused by chromosomal abnormalities.
For example, the normal male karyotype is 46, XY, and female is 46, XX. This condition arises when there is an extra X chromosome in the male karyotype, most commonly resulting in 47, XXY. The main cause of the XXY karyotype is errors in meiosis or mitosis during gamete formation, leading to chromosomal nondisjunction, producing XY or XX gametes that combine with normal X or Y gametes to create non-diploid embryos. Triggering factors include parental exposure to environmental pollution, medications, radiation, advanced age, and other influences. Typical symptoms include small, hard testes, azoospermia, and some patients may develop female-like breasts or sexual dysfunction. In summary, males with this condition are highly likely to be infertile, and the majority of male calico cats resulting from this genetic defect are also sterile and unable to produce offspring. Therefore, the probability of male calico cats appearing is extremely low! Fortunately, this condition does not affect their overall health, and they are no different from other cats in this regard ~ Nevertheless, calico cats are deeply loved by the Japanese, who believe that male calico cats bring good fortune, as the prototype for the Maneki-neko (lucky cat) is a male calico cat.
4.Are male calico cats completely infertile?
Not necessarily! First, make sure what you’re seeing is a true calico cat. This is because the following genotypes can also result in cats having three colors.
The first genotype: somatic mutation. Cats carrying the pheomelanin (red/cream) gene may occasionally have a small patch of tabby or black fur due to somatic mutations that cause an increase in the size of the color patches, leading to misjudgment of their color and not being true calico cats. This can be simply understood as similar to human moles or birthmarks.
The second genotype: chimeric cats. Chimera is a monster in Greek mythology with a lion’s head, a goat’s body, and a serpent’s tail. This genotype is named so because it is very similar to chimeric embryos. Chimeras are individuals with different genetic traits that are chimeric or mixed, meaning an organism has cells with two or more different chromosomal compositions coexisting, tolerating each other without rejection, and existing in a chimeric state. Tortoiseshell cats belong to this category, and the “two-faced” cats are particularly stunning.
The third genotype: XX and XY mosaics. This is a rare mutation related to sex chromosome aneuploidy and Y chromosome chimerism, where the individual has cells with different genetic compositions, such as XY/XXY, known as mosaic karyotypes, because, like mosaic tiles on a floor or wall, there is more than one type of cell. In this case, if the germ cells of a male calico cat can carry the normal combination of XY, they can be fertile.
The fourth genotype: XXY genotype. Most male calico cats have an extra X chromosome in their body cells, resulting in an XXY genotype, also known as Klinefelter Syndrome mentioned earlier. Among these four genotypes of male calico cats, only the fourth is infertile. The first and second are fully fertile, while the third may have partial fertility.
- Is it necessary to neuter a male calico cat?
Often, we cannot accurately determine a cat’s fur color pattern based on appearance; genetic testing is the gold standard. However, even male cats that are infertile may still experience estrus. Therefore, to avoid the troubles caused by estrus, it is recommended to take them to the hospital for examination or neutering.
- Are there cats with four colors in the world?
Biologically speaking, they do not exist. A cat can have up to three colors.