Why is it that orange cats are always male?
If you grew up around a lot of cats, you will probably know some male orange cats (also called ginger cats). But are ginger or orange cats always boys? Why are some cats born all orange, while others have orange mixed with other colors? What are these differently colored cats called, and are they a special breed? We will look at all of these questions in this article.
The color of a cat’s coat is determined by cat genetics. Like us, cats have a number of different characteristics that are passed on by their parents. They get some characteristics from the mother and some from the father.
The gene for an orange coat (known as the O gene) is a sex-related gene because it is carried on the X chromosome – one of the chromosomes that determine an animal’s sex. Female cats, like humans, have two X chromosomes. Males have one X and one Y.
To explain what happens when they breed, let’s take the example of tortoiseshell or calico cats. Tortoiseshell cats are orange and black/brown/gray; calico cats are tortoiseshell plus white. They are not a special breed: these colors can appear in many breeds of cat including non-pedigrees. But, except for a few rare cases of genetic abnormality, they are always female.
This is because tortoiseshell and calico cats have two X chromosomes: one carrying the O gene for an orange coat with white, and one that gives them their black/brown/gray colors. But if a male inherits the O gene, he has no second X chromosome to give him other colors, so he will be only orange and white.
So, are there any female orange cats? The answer is yes. First, it is possible for a tortoiseshell or calico cat to have so much orange coloring that she looks like a ginger cat, although if you looked closely you would probably find a spot of some other color on her somewhere. Even if she doesn’t have this, then genetically she would not be a true orange cat. She is really tortoiseshell – she just happens to look all orange. Some of her kittens would have the O gene and others could be black or tabby.
Second, it is possible to have a true orange or ginger female cat, but only if she has inherited the O gene from both her mother and her father. Her father would be ginger and her mother would be tortoiseshell, calico or, more rarely, true orange.
If the father is orange and the mother is also true orange with two O genes, then all of the kittens of both sexes will be orange.
If the father is orange and the female is tortoiseshell or calico, then the female kittens have a 50% chance of inheriting two O genes and coming out orange. If they inherit only one O gene, they will be tortoiseshell or calico.
Male kittens will only inherit one X chromosome. It always comes from the mother and it can be either one of her two. So on average, 50% of the male kittens from a tortoiseshell or calico female (which have one O and one non-O) will inherit the O gene and be orange. It doesn’t matter what the father looks like in this case, because a male doesn’t inherit his father’s X chromosome – he gets the Y from his father instead.
So most females with the O gene will have a non-O gene too, and turn out tortoiseshell or calico (tortoiseshell-and-white). Only a few of them will have two O genes. But males only ever have one of these genes, so males with the O gene will always be orange.
So orange cats are not always male. There are a lot more male orange cats, but there are some females too.