How often do tigresses become pregnant?

Another similar question would be how often do tigresses become sexually receptive? And to answer to both questions, on my research, female tigers produce a litter every two years. As a consequence, mating opportunities for male tigers are limited because in areas where there is plenty of prey, tigresses are usually pregnant or accompanied by dependent young. Tiger cubs in captivity. Image: BBC. And during this time, it is a period of anestrous which means a period of sexual quiescence between two periods of sexual activity. She is not receptive to male advances and therefore she may be sexually receptive only once every two years. Further, anestrus can be environmentally induced. In subtropical and tropical parts of the world tigers may mate and give birth at any time of the year. However, in Siberia, Siberian tigers appear to be seasonal breeders. For this species of tiger there may be a seven or eight month anestrous between breeding seasons. When the female tiger comes into heat sh...