Dr Bradshaw makes a nice observation in his book: Cat Sense: the Feline Enigma Revealed. In larger colonies of cats – and, of course, I’m referring mainly to feral cat colonies – females mate with several males in sequence. The large majority of their litter of kittens contains the DNA of more than one of the males – and…”multiple paternity within a single litter is therefore always a possibility”.
The female cat’s habit of offering herself to several males looks highly promiscuous. Perhaps it is one reason why some people don’t like the domestic cat and particularly feral cats. However, there may be an underlying purpose which, as usual, is all to do with survival of the species. She may be protecting her future offspring from infanticide. This is the killing of cubs (in the case of wild cat species) or kittens with respect to feral cats. Infanticide is when an incoming male kills kittens in order to ensure that all the offspring in the colony are genetically linked to him.
Each male would have observed the female being mated by others but he cannot know which of her kittens are his and which aren’t. Also, as each of the larger male cats has mated with several female cats none of them have the incentive to kill any of the kittens in the litters.
It is worth adding that female cats exert some choice in respect of a male cat. They sometimes show a preference for males who are from outside of their group thereby preventing inbreeding. This is the other side of the coin to what happens with carnivores and mammals when the males disperse thereby minimising the chance of inbreeding.
In small colonies, in which there is one resident male females don’t appear to have much of a choice when mating. Research indicates that only about one litter in five exhibits DNA from any other male. The female may have decided on their choice of male beforehand when she allowed him to live with her. However, sometimes males impose themselves upon the female.