Lions – passing on the genes

With the fences between Thornybush and Timbavati down, lions are crossing the old fence-line and we are getting questions about the phenomenon of infanticide i.e. when a male lion comes in and takes over a pride he will kill the offspring of his predecessor so that the females will re-enter oestrus. They are then ready to mate again and the new male can raise his own cubs and not those of the predecessor. This phenomenon does happen but not as often as expected – if the cubs are a year or more the new male will often fail because the lionesses and cubs fight together as a unit and repel him. Lionesses are sometimes wounded or even killed defending their cubs. And occasionally males do not even attempt to kill young cubs. Lionesses with very young cubs will sometimes hide their cubs from the male in an effort to protect them and then return to the new male as if they have no cubs. Amazingly these females enter a false or pseudo-oestrus to fool the male into mating but do not conceive. This is believed not to be a controlled phenomenon but rather more of a involuntary response controlled by hormones produced as a result of circumstances and behaviour. The only downside is that the lioness is forced to stay away from her cubs for a number of days and, as the cubs are still reliant on milk and/or parental care, they could starve. Generally the lioness will return to fetch the cubs after a few days, once the new male has settled and calmed. The male will then see the cubs and accept them, as he will not know that they are not his cubs! It is believed that this acts as a delaying mechanism that gives the new males in this state of flux time to settle, with the new males either staying or being displaced by a stronger male or coalition. Ultimately this avoids the waste in maternal energy when lionesses have cubs unnecessarily killed because of the temporary presence of the males.