Calico cats are a well-known type of domestic cat with white fur and splotches of orange and black. If you have ever met a calico cat, chances are it was a female. But why is that?
What Is a Calico Cat?
To begin, it is crucial to understand that a calico cat is not a breed of cat. Rather, “calico” is more of an adjective that describes a coat type, similar to short gray hair or long orange hair. Calico cats can be of almost any breed as long as they have a tri-colored coat.
Calico cats are typically white with black and orange patches on their backs, tails, and faces. These patches can also occur elsewhere in the body, but these areas are most common.
Are All Calico Cats Female?
Calico cats are almost always female because the gene for orange fur is on the X chromosome. Females have two X chromosomes, while males have one X and one Y chromosome. This means that for a male to be calico, he would need to inherit two copies of the orange gene, one from each parent. This is very rare, so most calico cats are female. According to Cornell University’s College of Veterinary Medicine, only around 1 in 3000 calico cats are born male.
Why Are Male Calico Cats Rare?
To understand why male calicos are rare cats, you need to understand some basic genetics.
The sex of a cat is determined by the X and Y chromosomes. The mother always gives an X chromosome, while the father can give an X or Y chromosome. Typically, each parent only gives one chromosome, resulting in a combination of XX or XY. The XX pair results in a female kitten, while the XY pair results in a male kitten.
Coat color is a sex-linked trait, which means it is determined by the X chromosome. This means that males and females can have an X chromosome that causes them to be black or an X chromosome that causes them to be orange. However, a typical male cannot be both black and orange, because they only have one X chromosome, while females have two.
To elaborate, male calico cats are only born when there is a genetic abnormality that results in three sex chromosomes: two X chromosomes and one Y chromosome.
This is known as Klinefelter syndrome, and it can occur in both humans and cats. During the division process in which the kitten should receive either the father’s X or Y chromosome, a complication results in the kitten receiving both. Since they also receive the chromosome from the mother, they end up with a set of XXY chromosomes.
While it is possible for a male cat to be calico, this can also lead to other complications, such as sterility and a variety of health problems. However, despite these possible complications, male calico cats can still live long, healthy lives with their loved ones.
