A male tortoiseshell cat is very rare, as over 99.96% of tortoiseshell cats are female.
Cats are the same as humans in that two X chromosomes make for a female cat and a male cat will have one X and one Y chromosome.
The reason that male tortoiseshell cats are so rare is that two X chromosomes are needed to produce the beautiful range of red, black, orange, white and autumnal colours that are found in the coat of a ‘tortie’.
Although this means that it is almost impossible for a male cat to inherit the tortoiseshell colours, very occasionally a male tortoiseshell is born if the cat has an extra strand of DNA and has an extra X chromosome.
This means that he will have an imbalance in sex chromosomes, so he is very likely to be sterile – and this is a condition that can also occur in humans (not the tortoiseshell colours, but the extra X chromosome!)
Studies vary from 1 in 1000 to one in several thousand cats being born as a male tortoiseshell cat, and although they are so rare this does not necessarily mean they are very valuable. They will look very similar to other torties, and they cannot pass on the tortoiseshell colours.
There have been various reports in the media over the last few years regarding male torties, including that of a male tortoiseshell kitten that was found on the streets of Colwyn Bay in Wales in October 2019.
You can read the full report on the BBC website, which reports that it didn’t take long for the male tortie to find a home!
We would love to hear from anyone that owns a male tortoiseshell cat or has come across one.