Tortoiseshell cats are generally female; males are extremely rare. Key points:
- Female tortoiseshells are common due to having two X chromosomes (one X from each parent) that allow the characteristic mottled pattern to appear without affecting viability.
- Male tortoiseshell cats are very rare because a typical male mouse/kitten would need an unusual genetic setup (such as an extra X chromosome, XXY), which occurs in about 1 in 3,000 tortoiseshell cases and often results in sterility or other health issues.
- Because of this, most tortoiseshell cats you encounter will be female, and finding a male tortie is a noteworthy rarity for breeders, shelters, and enthusiasts.
If you’d like, I can pull up the latest reliable sources or explain the genetics in more detail.
