You can get tortie/calico males due to genetic or developmental quirks.

The most common cause seems to be chimerism. Two embryos bump into each other in the womb and merge together. If one is black and the other is ginger and one or both are male the result may be a tortie tomcat (or calico tomcat if the embryos had white patches).

The next most common cause seems to be XXY genetic makeup (Klinefelter Syndrome). An embryo gets one X chromosome with the black gene, one X chromosome with the ginger gene and one Y chromosome that makes it male. This chromosomal abnormality used to be thought the most common cause, but recent research shows chimerism is probably more common.

The third cause is somatic mutation. A ginger male embryo devlopes black patch in the same way as some babies develop port wine stain birth marks.

Those with XXY makeup are infertile and often have other physical abnormalities due to having too many copies of some genes..

Those with chimerism are fertile but they can only pass on either the ginger colour or the black colour, but not both, to their offspring.

Those with somatic mutation are fertile because the black patches are just birthmarks.