are calico cats always female

Calico cats are almost always female—about 99.9% of calico cats are female. This is due to the genetic mechanism behind their coat coloring, which is linked to the X chromosome. Female cats have two X chromosomes (XX), allowing them to carry both black and orange color genes on different X chromosomes, resulting in the calico tri-color pattern. Male cats have only one X chromosome (XY), so they generally cannot have both black and orange fur in combination, making calico males extremely rare. The rare male calico cats usually have a genetic anomaly called Klinefelter's syndrome, where they have two X chromosomes and one Y chromosome (XXY). These males often are sterile but can live healthy lives otherwise. Hence, while calico cats are not exclusively female, males with calico coloring are exceedingly uncommon and usually sterile due to this genetic condition.