Not all lions kill cubs, an act of infanticide. It is male lions who do it sometimes. The world of the lion is brutal and unforgiving. We know that lions live in prides or groups – the only cat species who positively do this. The lions in these groups are related. The male lions dominate the group and their ‘tenure’ or hold over the group may last about 2 to 3 years.
In the Serengeti the male lions’ tenure lasts 26 weeks based on a research project at which point a group of males take over their pride. When they do this they want to have their own offspring as soon as possible. They can’t delay and wait till the females are receptive before they can mate and procreate. So they kill the cubs. When this happens the females immediately become receptive to mating. The incoming males can then mate with them to create their own offspring.
SEE MORE ON CUBS AT BASE OF PAGE…
They do this quite quickly because, as mentioned, they have 2+ years to raise their cubs to protect them until the next group of ‘takeover males’ arrive and push them out. So the underlying reason why male lions kill cubs is so that they can get on as quickly as possible to create their family because there is no time to wait for the ordinary course of events to unfold. It is about speed and a desire to have their own young.
That said it does not always work out like that. Sometimes females can hide their cubs and defend them. They raise them with their new cubs, the offspring of the incoming males. Or they might be pregnant and when they give birth the incoming male treats the cubs as his own.
As mentioned, the killing of lion cubs by incoming males is called infanticide. The same word is used for humans killing infants.