A captive Sumatran tiger, the smallest of the five living tiger subspecies, lounges at a zoo in Asia. Three other known tiger subspecies have gone extinct, and all five remaining subspecies are considered at risk of extinction.

The Sumatran tiger lives in the wild only on the Indonesian island of Sumatra (Indonesia map). The nonprofit World Conservation Union lists the Sumatran tiger as critically endangered, noting that only about 250 mature individuals are believed to remain.

Toyger creator Sudgen thinks that the new cat breed, which resembles a toy tiger, will be perfected by 2010, around the same time that she believes the last of the tigers will be living in zoos.

"The results [of toyger breeding] could be the last chance for humans to make up for the loss of these species on Earth due to our stupidity," she said.

• More Photos in the News
• Today's 15 Most Read Stories
• Free Email Newsletter: Focus on Photography