Endangered Mountain Vipers Born at St. Louis Zoo [VIDEO]

Nine rare mountain vipers were born at St. Louis Zoo's herpetarium in August, the zoo announced Tuesday.

Ocellate mountain vipers (Montivipera wagneri) are native to eastern Turkey and northwest Iran. The endangered snakes were thought to be extinct for nearly 140 years prior to being "re-discovered" in Turkey in 1983. Since then, many of the snakes have been scooped up by overzealous Turkish and European snake collectors, keeping their numbers in the wild low.

"This is a serious threat for the future survival of the species, which has already been wiped out in much of its very small range," the St. Louis Zoo wrote of the reptiles.

Currently about eight inches long, the ocellate mountain vipers were born Aug. 16. When they are fully grown, they can be as long as three feet.

In the wild, the venomous snakes are found on the dry mountain slopes where the weather is cool at night. The snakes' orange and brown spotting helps it blend in with its surrounding.

Ocellate mountain vipers are only found in three zoos in the United States, according to local St. Louis news station KSDK .

The St. Louis Zoo's conservation program is designed to increase the species' population. The zoo coordinates the snakes' Species Survival Plan, a cooperative breeding program under the auspices of the Association of Zoos and Aquariums which sees North American zoos working together to ensure species survival.

The conservation of the ocellate mountain vipers at St. Louis Zoo is an extension of its conservation work with the snake's relative the Armenian viper, The Associated Press reported.