Suggestions as to why male domestic cats commit infanticide

It appears that in 2023 we are still somewhat unsure as to why male domestic cats kill young offspring of females to whom they are unrelated. One study published in 1999 found six cases of infanticide by the domestic cats living in rural locations. These appear to have been barn cats.

They found that fully adult and sexually mature male, rural domestic cats killed six kittens within the first week of life.

The scientists state that "The killing pattern was generally the same as that described in lion". A clear statement that there are similarities in behavior between lions and domestic cats.

The females tried to save their newborn kittens without success. They reacted aggressively but couldn't prevent the killing of their kittens by these unknown male cats.

The scientists hypothesised the following:

• Male domestic cat infanticide is due to the same reasons that male lions kill offspring in order to sire their own offspring with the females who'd lost their kittens as they then came into season.
• That male domestic cat infanticide is an abnormal behaviour because of disturbances in their environment.
• That this behaviour is caused by "selection pressure" to which males react differently. I take this to mean that there is competition to breed amongst the males which causes some males to commit infanticide while others don't. They describe this as "a polymorphism of infanticidal and non-infanticidal males to evolve". The word "polymorphism" means a variety of forms of behaviour.

In a separate study, it was found that farm cat colony behavior was amicable within the colony and aggressive to outsiders. Adult females created communal nests and cooperated between themselves in raising their young. This mirrors female lion behavior by the way.

They found that there was one case of infanticide by an unrelated adult male. They agreed that this was not a unique example.