Although critically endangered, wild tigers still prowl the border of India and Bangladesh — one of the most densely populated places on earth; the western Terai of India and Nepal; the untamed borderlands of Vietnam, Laos and Cambodia; and the vast boreal forests of the Russian Far East.

How many roam is the million dollar question.

"Estimating the number of tigers in a population has always been a contentious issue," says John Seidensticker, chairman of the Save the Tiger Fund Council, and senior scientist at the National Zoological Park, Smithsonian Institution. "Estimates provided by range countries are, in most cases, based on nothing more than optimism."

One thing for sure is that a century ago there were eight subspecies of tiger, all native to Asia. Now there are only five: The 1980s saw the last of the fearsome Javan tiger, a 250-pound animal that could take down 2,000-pound bulls. The Caspian tiger went extinct in the 1970s. And the last Bali tiger probably died in the 1940s.

Here's a brief description of those subspecies still living and a bit about their current status:

South China Tiger view »

Amur Tiger view »

Bengal Tiger view »

Indochinese Tiger view »

Sumatran Tiger view »