The rarest snake in the world, the Antiguan racer, has slithered back from the brink. The population has increased ten-fold, from a low of 50 in the 1990s to over 500.
The snakes are confined to Great Bird Island, off the coast of Antigua, where many of them have been killed by imported rats. The snakes previously lived on mainland Antigua as well, but introduced mongooses wiped them out.
Conservationists have now removed the rats from 12 of Antigua’s offshore islands. As well as protecting the racers, this decision has benefited local birds. Caribbean brown pelicans and white-crowned pigeons have both become much more numerous.
source : http://www.newscientist.com/blogs/shortsharpscience/2010/11/rarest-snake-back-from-the-bri.html