—Feline Behavior Specialist 🇺🇸
Calico cats are known for their beauty, as well as having very colorful personalities, but is there scientific proof to back that up?
What exactly gives them that beautiful coat? Are they always female?
Let’s dive into the incredible and female-dominated world of calico cats.
What is a calico cat?
Calico cats are tri-color and have mostly white with patches of black and orange/red. If the same colors are more subdued, the cat is called a diluted calico. If the white is missing entirely and the cat is black/brown with orange/red, it’s a tortoiseshell or tortie.
Is calico a breed?
No, it’s a color and pattern. Pointed breeds, like Siamese or Himalayans, and solid-color breeds like Bombays, British Shorthair, and Russian Blue, do not accept calicos. Common breeds with calicos include Manx, American Shorthair, Maine Coon, Japanese Bobtail, and Scottish Fold.
What genetically determines a cat will be a calico?
Get ready for your science lesson of the day. We’ll try to simplify it as much as possible by doing a progressive explanation and making genes talk! 🧬👩⚕️
The two colors all cats originate from are orange and black. Diluted versions may be seen (like buff or grey). White is something different we’ll discuss in a minute.
Females carry XX chromosomes, and males XY.
The orange color gene is only on the X chromosome, and it can present two ways: orange or non-orange which is black. What it basically means is the gene tells cells, “Go orange!” or “Go black!”
If a male has the orange gene on the X chromosome, the gene tells the cells, “Go orange!” If he has the non-orange gene, that gene says, “Go black!” The color gene is not connected to the Y, so the male can only have the color on the X chromosome of orange or black, not both.
Because females have XX, they can carry orange on one X and non-orange on the other X, meaning they will present with orange and black fur (more on patterns in a minute).
In the rare case a male is a calico, he has an extra chromosome, carrying XXY. It’s the same as females where one X says “Go orange!” and the other “Go black!” This is more of a genetic oopsie which makes the male calico always sterile.
These males often suffer from Klinefelter’s Syndrome, which can lead to medical issues like cognitive and developmental issues; frail bones; higher body fat leading to heart disease, arthritis, and diabetes; and a shorter lifespan.
But where does the white come from?
White in calicos or bicolor cats (orange and white; gray and white; black and white) is from a different gene, known as the spotting gene. No matter how much white is on a cat, it’s considered spotting (crazy, right?). White spotting isn’t linked to sex, so males and females can have white in their coat.
Genes are expressed by letters, and the dominant gene for spotting is S, and the recessive is s. Since genes are in pairs (one from mom, one from dad), SS and Ss will result in white spotting or “Go white!” If the female also has XX with orange and black, she will be a calico.
A cat with XX of orange and black plus the recessive spotting combo of ss will have no white and be a tortoiseshell!
The craziest part of all of this? Some completely white cats carry SS, so they have white “spotting’ all over!
To further complicate things, some completely white cats are called dominant white, which is a different gene, W. It overrides all other genes related to pigmentation. We’ll cover that in another article.
Do any two calicos have the same pattern?
No, kind of like fingerprints or DNA, the pattern is specific to each calico cat. Here is why.
Remember that females have XX chromosomes. So, in female mammals, each individual cell cannot express both X chromosomes (they are not arguing about what color she should be). One X will be deactivated (or silent), meaning only one X will be activated (or speaking).
Some cells are being told, “Go orange!” and some are being told, “Go black!” – but no cell is being told both at the same time. There is no conflict within the cell. The gene speaking in each cell is entirely random, resulting in random orange or black patches of fur!
What color eyes do calicos have?
Nearly any color! Most commonly blue, green, or orange.
How long do calicos live?As mentioned earlier, the rare male might have a shorter lifespan, but female American Shorthair calicos can live 18-20 years, where Persian calicos live 12-15 years.
What are their personalities like?
Most feedback is anecdotal and not based on research, but it’s common for calicos to be a combination of loyal and sweet, with streaks of independence and spunkiness.
Given that nearly all calicos are female and females tend to have more sassiness than male cats, it isn’t surprising that many say their calicos have some attitude.
Are calico cats considered good luck?
Yes, the Japanese lucky cat figurine (waving cat - you’ll often see it at the front desk of restaurants) is usually calico. Japanese sailors are said to have traveled with calico cats onboard to protect them from angry spirits.
Besides Klinefelter’s Syndrome in rare calico males, are there any diseases that seem to be genetically tied to calicos?
No, there aren’t, however, their color coat can make it difficult to spot issues with their skin, including fleas and ticks. To keep an eye on things, brush your cat once a week and always stay up to date on flea and tick meds.
According to Merck Veterinary Manual, the most commonly reported congenital and inherited defects in cats are:
- Cerebellar hypoplasia (CH) aka Wobbly Kitten Syndrome - Underdeveloped cerebellum (which controls mobility and balance)
- Eye and eyelid defects
- Heart defects
- Cryptorchidism - One or both testicles absent
- Polydactyl - Extra toes
We hope you have an even greater appreciation for the beauty and science behind calico cats. Whether the sassiness associated with them is true or not, we still love them all the same.
Caster.com, 8 Questions About Calico Cats Answered.
AllAboutCats.com, All About Calico Cats
Catological.com, Facts About Calico Cats
ASPCApetinsurance.com, Fun Calico Cat Facts
LetsTalkScience.com, The Science Behind the Calico Cat’s Colours
IB.Berkley.edu, Basic Genetics as Revealed by Cats
Merckvetmanual.com, Congenital and Inherited Disorders Affecting Multiple Body Systems in Cats
Article by Elizabeth Italia 🙋♀️
Cat Behavior & Fostering Specialist