As males and females interact regularly in lion prides, there is no need for lionesses to advertise their impending sexual receptivity by calling or by increasing scent marking. Instead, male lions determine a lioness’s state of sexual receptivity by smelling her bottom together with her willingness to mate. If she is approaching heat or in heat the male lion will stay with her.
A lioness in oestrus will walk a few paces then lie down in front of the male who remains close by, moving as she moves. In addition she will roll, twist and turn and jump up to walk.
When the male lion attempts to mount the female she may swat at him, growl and snarl. When the male lion is allowed to mount the female he may grasp the female by the neck in his jaws, in a way which is very typical of domestic cats when they mate.
Lion copulation on average lasts for 21 seconds, the minimum time being about 8 seconds and the longest being 70 seconds. It occurs once every 25 minutes. One pair of captive lions were recorded as having copulated 360 times in eight days. On another occasion, a nomadic male living in the wild was observed to mate 157 times in 55 hours. During this time he didn’t eat.
Oestrus lasts about four days and recurs every two or three weeks until the female conceives. Male lions living in a pride rarely fight each other over receptive females unless the ownership of the female is unclear or if a consorting male gets too close.
Source: Wild Cats Of The World by Fiona and Mel Sunquist.