This document discusses animal extinction and provides three key points:
1) A species becomes extinct when the last individual dies and can no longer reproduce, and a species may be functionally extinct with only a small number of individuals remaining.
2) Habitat destruction, pollution, wildlife trade, and overharvesting are the main causes of extinction.
3) Project Tiger was initiated in India in 1972 to protect Bengal tigers and help increase their population from 1,200 in the 1970s to over 2,000 currently.