White lions are not albinos. Their white color is caused by a recessive trait, called leucism, derived from a less-severe mutation in the same gene that causes albinism, distinct from the gene responsible for white tigers. They vary from blonde to near-white. This coloration does not appear to pose a disadvantage to their survival. White lions were considered to have been technically extinct in the wild between 1992 and 2004, when the Global White Lion Protection Trust achieved the first successful reintroduction of white lions to their natural habitat. These prides have continued to hunt and breed successfully in the wild, whilst other occurrences of white lion births have been reported in the greater Kruger region since then.