Are male calico cats akin to unicorns? Oakland reader wants the real story

DEAR JOAN: I’m planning on adopting a cat next year. I’ve always wanted a calico cat, so I’ll be looking for one. I just think their coloring is so pretty and unique.

My friend and next door neighbor told me that if I get a calico, it will be a female. I wasn’t looking specifically for a male or female, just a happy, beautiful cat, but now I’m wondering – are all calico cats really female?

My friend said if anyone ever found a male calico, they’d be rich because they could use it to breed more male calicos. That didn’t sound quite right to me.

Can you tell me the real story?

— Natalie, Oakland

DEAR NATALIE: Your friendly neighbor is sort of right, but since you asked, here’s the full story, explained by someone who only got a B+ in biology. I would have gotten an A, but I couldn’t bring myself to collect any more insects for the class project.

Part of the calico-ness of calico cats is dependent on the sex. Like in humans, females have two XX chromosomes, and males have the XY. A calico cat needs two Xs, one with the genetic coding for the black color, and one with the orange. Provided that one X doesn’t dominate the other, genetics mandates that the cat will be orange and black. (I’ll get to the white on the calico in a minute.)

Because males don’t typically have two Xs, they lack the genetic instructions to produce the two colors. Every once in a while, however, a mutation gives a male cat two Xs and a Y. In that case, the male could be a calico. It’s rare, but it happens. The genetic hiccup usually means a male calico has other genetic mutations that can make him fragile and shorten his life. However there are cases where the boy is just fine and has a normal lifespan.

In addition to the black and orange genes, calicos must also inherit the gene that produces white fur. That gene can exist in male or female cats.

If your friend happens to find a male calico, don’t imagine great riches will follow by breeding a small army of the multi-colored cats. Male calicos are born sterile.

Good luck in finding your dream calico. Send me a picture of her when you do.

DEAR JOAN: With your help and the support of your amazing readers, we successfully reached our fundraising goal of $500,000 to protect and steward Krane Pond. We received 257 donations totaling $61,361 from your readers and we are truly grateful.

As we celebrate this achievement, we kindly ask that your readers keep us in mind for their year-end giving. Their continued support will enable us to deliver more land conservation successes in the new year.

Send donations to Save Mount Diablo, 201 N. Civic Drive, Suite 190, Walnut Creek, CA 94596 or https://savemountdiablo.org/donate.

— Ted Clement and Seth Adams, Save Mount Diablo

DEAR TED AND SETH: This is truly a time of giving and honoring all life, and I echo your sentiments. There are so many great organizations doing amazing work that could use a little extra help now and throughout the year.

Animal Life runs on Mondays. Reach Joan Morris at AskJoanMorris@gmail.com.