Siberian tiger cubs at play at the Olmense zoo. Full blown mayhem
For those of you who don't know already (I get the question a lot): white and orange/brown tigers are exactly the same species, just as black and 'normal' leopards are a single species, the difference is simply the result of basic genetics. The gene for white fur is a recessive or 'weak' gene, just like blue eyes in people, so in order to be white, cubs need to get a white gene from both their parents in order to turn out white. These cubs' mother Ria is brown, but she can get white cubs, so she has to have one brown/orange gene and one white gene. Since the orange/brown one is the stronger, dominant gene that is the one that actually surfaces and determines the fur colour. As a result she looks brown. The dad, Rakhan is white, so he has to have two white genes and can only pass on white genes to his cubs. In this litter, three of the cubs got the white gene from mom and the white gene from dad, so they look white. One cub got the brown/orange gene from mom and the white gene from dad, so he looks brown/orange because this is the stronger gene.