They may be facing extinction in India, China and Siberia, but in the US, tigers have found a new lease of life — after a fashion. According to the American Zoo and Aquarium Association, more than 12,000 tigers are kept as pets — double the number thought to exist in the wild. The craze persists, despite concern among politicians and animal-welfare groups. Michael Jackson and Mike Tyson each have one; the magicians Siegfried and Roy are known for their specially bred white tigers in Las Vegas; the internet and specialist trade magazines advertise exotic-animal auctions and ‘jungle-cat reduction sales’. The National Alternative Pet Association — ‘Do people put you down because your pet isn’t a socially acceptable cat, dog or goldfish?’ — promotes ownership of endangered species. Prices are not particularly prohibitive: $1,000 for a generic cub, $3,500 for a pair of Bengal tigers, then rising to $15,000 for a more fashionable white tiger. . . Today in Texas there are said to be 4,000 pet