Calico Cats:
* Have three colors: Black, white, and orange (or cream).
* Patches are more distinct: The colors are clearly separated in large, defined patches.
* More common in females: Calico coloration is primarily linked to the X chromosome, making it much more common in female cats.
Tortoiseshell Cats:
* Have two colors: Black and orange (or cream).
* Patches are smaller and blended: The colors are often mixed and intermingled, creating a more mottled appearance.
* Also mostly female: Tortoiseshell coloration is also linked to the X chromosome, so most tortoiseshell cats are female.
The Key Difference:
The most obvious difference is the presence of white in a calico cat. Tortoiseshell cats never have white fur.
A Word of Caution:
* Male Calicos and Tortoiseshells: While rare, male calico and tortoiseshell cats do exist. They typically have an extra X chromosome (XXY), which can cause certain health issues.
* Color Variations: There are color variations within both calico and tortoiseshell cats, such as blue-cream (diluted orange) or tabby patterns.
If you're still unsure, it's always best to consult a veterinarian or a cat expert for confirmation.