In December 2013, a white Bengal tigress called Saraswati at Myrtle Beach Safari Park in South Carolina, USA, gave birth to the world's first confirmed white ligers. Ligers are hybrids resulting from the successful mating of a lion with a tigress, and several have been born in captivity before, but these white ligers' father was a white African lion called Ivory – the first time that a white lion had successfully mated with a white tigress and produced white hybrid cubs.White colouration in lions and also in tigers is known as leucism and is caused by recessive mutant gene activity, so both parents have to carry the mutant gene for any white offspring to result. As all four of the cubs in the litter produced by Ivory and Saraswati were white, however, with no normal-coloured cubs at all. This suggests that the same gene may be responsible for white colouration in both lions and tigers. The four cubs were named Odin, Sampson, Yeti, and Apollo, and all four have survived and are maturing well, with Yeti already notably large.