SAN JUAN, Puerto Rico (AP) _ Bird specialists released 10 captive-bred Puerto Rican parrots into the Caribbean rain forest to join the last 40 such parrots still existing in the wild.

The release, made Tuesday and announced Wednesday, is the result of 32 years of work to bring the endangered species back from the brink of extinction.

It ``marks a milestone in our long journey to the recovery of this species,'' said Hilda Diaz-Soltero, associate chief of the U.S. Forest Service, which was among several U.S. and Puerto Rican agencies trying to save the brilliant green birds which have distinctive red frills above their beaks.

Their population dropped from an estimated 2,000 in the 1930s to an all-time low of 13 in 1975, as deforestation and hurricanes claimed their natural habitat and they fell foul of hunters and nest robbers.

The 10 birds freed in Puerto Rico's northeast Caribbean National Forest, called El Yunque, were chosen from 113 captive in two aviaries on the island. Information learned from their release should help in establishing a second population in north-central Puerto Rico.