Rare Male 'Torbie' Kitten Up for Adoption at Atlanta Humane Society

The odds aren't quite one in a million, but when you weigh all of the factors that brought Right -- a male tortoiseshell and tabby mix called a "torbie" -- to the Atlanta Humane Society, they might as well be.

One look at Right's orange and black coloring and striped markings and it's obvious the cat's a torbie, which in itself isn't very shocking. The surprise came when Right was sent to be altered (or fixed, as it's commonly known).

"His intake paperwork said Right was a female," said Dana Widmer, supervisor of spaying and neutering at AHS. "When we shaved the area for surgery, we discovered he was a male. With his coloring, I immediately knew he was extremely rare."Instead of spaying Right -- who was named in a group of rescue kittens from Coweta County in Georgia that also featured Left, Up and Down -- veterinarians neutered the kitty, verifying beyond a shadow of a doubt that he was, in fact, a rarity.

When asked how rare male tortoiseshell cats are, Widmer responded, "I've worked in animal welfare for eight years, mostly with cats, and I've never seen a male torbie, or any tortoiseshell."

Torbies got their name by mixing tortie, a nickname for tortoiseshell cats with orange and black coloration, and tabby, which describes a striped cat.

Along with torties and calicoes -- which are tortoiseshell orange and black mixed with white patches -- torbies are one of only three kinds of cats with orange and black colorations.

While female torbies aren't uncommon, male tortoiseshells are few and far between.

According to VeterinaryPartner.com, the reason male tortoiseshell-colored cats are so rare is because feline coat colors are determined by which allele (gene) is present on the X chromosome. Both black and orange colorations are "co-dominant" genes -- if they exist together, they will both show, but if only one is present, the coloration will be either orange or black.

Females have two X chromosomes, which allows both orange and black colorations to show. But males typically have one X chromosome and one Y chromosome -- allowing only one color to show.

For a male cat to have a tortoiseshell coloration, it must have an extra X chromosome, making it XXY. In humans, this is known as Klinefelter's syndrome. As with humans, these cats are almost always sterile because of the imbalance in sex chromosomes. ...

via Rare Male 'Torbie' Kitten Up for Adoption at Atlanta Humane Society.