Tortie vs. Torbie: What is the Difference?#

If you have a female Maine Coon with a coat that looks like an explosion in a paint factory—black, red, cream, and maybe white—you have a Tortoiseshell. But is she a Tortie or a Torbie?

The terms are often used interchangeably by pet owners, but to a breeder, they mean two genetically different things.

• Tortie: A Solid cat with red patches.
• Torbie: A Tabby cat with red patches.

Here is how to tell them apart, and why almost all of them are female.

The “Orange” Gene ($O$)#

Both cats share the same engine: the Sex-Linked Orange gene. Because the Red gene is on the X chromosome, females (XX) can have one Red X and one Black X. This results in a mosaic: patches of red and patches of black. [cite_start]This is the Tortoiseshell. [cite: 2920]

1. The Tortie (Solid)#

• Genetics: Non-Agouti ($aa$).
• Appearance: Patches of Solid Black and Solid Red.
• The Clue: Look at the black patches. Are they solid black like a panther? If yes, she is a Tortie. (Note: The red patches will always show some stripes because the Red gene masks the solid gene, but the black patches will be solid)[cite_start]. [cite: 2920]

2. The Torbie (Patched Tabby)#

• Genetics: Agouti ($A-$).
• Appearance: Patches of Brown Tabby and Red Tabby.
• The Clue: Look at the “black” areas. Are they actually brown with black stripes? Do you see a distinct “M” on the forehead? Do you see white eyeliner around the eyes?
• The Name: “Torbie” is a portmanteau of “Tortoiseshell” + “Tabby.” [cite_start]In the show ring, CFA calls this a Patched Tabby. [cite: 2921]

3. The Calico (Tortie with White)#

If you add the White Spotting ($S$) gene to a Tortie, you get a Calico. Robinson’s Genetics explains an interesting phenomenon: The more white a cat has, the larger and more distinct the red and black patches become.

• Low White: Brindled, messy mix of colors.
• [cite_start]High White: Distinct, clean islands of red and black on a white body. [cite: 2921]

Conclusion#

Check the forehead.

• Solid Black/Red Forehead? Tortie.
• “M” Mark and Eyeliner? Torbie. Either way, you have a cat with “Tortitude”—the legendary spicy personality that seems to come with the red gene.

References#

1. Vella, C. et al. (1999). Robinson’s Genetics. “Red and Tortoiseshell,” p. [cite_start]158. [cite: 2920]
2. Robinson, R. “Sex-Linked Orange,” p. [cite_start]143. [cite: 2920]
3. Walsh, L.G. (2013). The Maine Coon Cat. “The Colors of the Coon,” p. [cite_start]16. [cite: 1070]
4. CFA. Maine Coon Breed Standard: Parti-Color Division.