The Tortoise Shell
“Usually a combination of grizzle, kite, one dose of recessive red (optional) on a blue bird makes torts also known as tri-colour.”
Sorry I can’t give credit for the description above, but I failed to note what forum I copied it from.
I’ve always admired the torts in rollers but never knew what it took to make them. I’ve thought it was like almond that you had to have one to make more, but apparently not.
When mating Torts remember the grizzle factor. If you mate Tort to Tort for several generations the color will get lighter and lighter. The easiest way to darken them back up is to mate in a kite (t-check with bronzing in the wings)
I do want to close with one observation. In a forum there once was a guy claiming that like Tortoise Shell cats that only females were fertile. This is a total myth. As I sit typing this, I have productive Tort hens in my loft.