* Genetics: Calico coloration is determined by the X chromosome. Female cats have two X chromosomes (XX), while males have one X and one Y chromosome (XY). The genes for black, orange, and white fur are carried on the X chromosome.
* The Exception: In rare cases, a male cat can be born with an extra X chromosome (XXY), a condition called Klinefelter syndrome. This extra X chromosome allows for the expression of both black and orange fur, resulting in a calico pattern.
So, while a male calico cat is possible, it's extremely uncommon. It's much more likely for a calico cat to be female.