Dear Most Esteemed and Knowledgeable Kitties:
It is said that a female orange kitten comes from a female that is calico or tortoiseshell and an orange male. I am wondering if you could explain how my black male and my friend’s calico could possibly have an orange female kitten.
Thomas: Well, Teresa, it’s interesting that you should ask this question now. A memory of our dear, sweet Kissy, an orange female cat (that’s her in the photo), came up on Mama’s Facebook page today.
Bella: The short answer is, fur color inheritance says it’s not possible that your black cat could be the kittens’ father.
Tara: A while ago, we interviewed a biology professor, who told us all kinds of cool things about how orange cats inherit their fur color.
Thomas: The main reason a black cat can’t father orange kittens is that the genes for orange color simply aren’t there in a black cat.
Bella: You see, the genes that control fur color are on the X (female) chromosome, and male cats only have one X chromosome.
Tara: The orange gene masks other colors, including black, so there’s absolutely no way a black cat could father orange kittens.
Thomas: If your black cat and the calico cat mated, you’d likely have black, black and white, and perhaps some calico or tortoiseshell females. The photos you sent with your question show a litter of orange striped kittens, and no black or calico ones.
Bella: So, if your black cat couldn’t have been the father, even if you saw him and your friend’s tortoiseshell cat mating, how could that have happened?
Tara: Well, the answer is, your friend’s calico must have mated with an orange cat.
Thomas: If she goes outside, or if she got outside by accident while she was in heat, it’s not too hard to imagine that she could have gotten impregnated by at least one other cat, because litters of kittens can have more than one father.
Bella: Cats are what’s known as induced ovulators. That means when a cat is in heat and she mates, the act of mating causes her to release eggs from her ovaries. The eggs are then fertilized by the sperm of the male cat.
Tara: A female cat can mate multiple times while she’s in heat, but the first sperm cells into the uterus will be the ones that fertilize the eggs.
Thomas: And mating can happen within minutes of a cat in heat and a male cat meeting.
Bella: I sure am glad I never had to mate! The shelter made sure I was spayed when I was a little kitten.
Tara: I’m spayed too, and I’m so glad. I could have gotten pregnant while I was wandering around outdoors if I hadn’t been, and that would only have made my troubles worse!
Thomas: And of course, I’m neutered, so I could never have fathered any kittens!
Bella: So, the answer to your question “How did my black cat father orange kittens?” is “He didn’t.”
Tara: Ask your friend if their calico cat got out any time while she was in heat. The answer will most likely be yes. And in my experience, orange male cats tend to be really strong and hardy…
Thomas: Hey, wait a minute! I’m strong and hardy, and I’m not an orange cat! I’m a Most Puissant Rat Slayer and Protector Of All My Ladies!
Bella: Oh, Thomas, Tara wasn’t saying you’re not strong and hardy! She’s just saying that she’s seen a lot of big, strong orange cats.
Tara: So, Teresa, we hope that answers your question. If you have any more questions about cat genetics, please feel free to ask. By the way, those orange kittens are super-cute!
Thomas: We do recommend that you get the cats and kittens spayed or neutered as soon as possible. Female cats can go into heat very shortly after they have kittens.
Bella: If finances are an issue–and we totally understand that, because Mama says we’re not rich, either–there are lots of resources available to help you with the cost of spaying and neutering your cats.
Tara: We’d suggest contacting your area shelters to see if they offer low-cost spay/neuter services, or if they know an organization that does. Also, SpayUSA and the Humane Society of the United States has a pretty comprehensive directory of spay/neuter assistance programs available in the U.S. There are probably similar directories in other countries.
Thomas: What about you other readers? Have you seen litters of kittens with unexpected fathers, or litters that look like they had multiple fathers? Please share your kitten experiences in the comments!