By Erik Derr (staff@latinospost.com) | First Posted: Jul 21, 2013 10:52 PM EDT

Two Persian leopard cubs were born in a Russian national park last week, the first such event in 50 years, a statement from the World Wildlife Fund said.

The endangered Persian leopard is one of the largest leopard subspecies and once heavily populated southwest Russia's Caucasus Mountains and surrounding region along the southern Caspian Sea.

But, as the result of heavy poaching and the loss of the animal's natural habitat through the 20th century, the animal ended up on the list of endangered species compiled by the International Union for the Conservation of Nature.

Now, it's believed only about 1,290 Persian leopard adults are alive in the wild.

Part of an effort to reintroduce the leopards to the wild, the two newborns were bred at the Persian Leopard Breeding Rehabilitation Center in Sochi National Park. The cubs' mother and father were transferred to the center in 2012 from Portugal's Lisbon Zoo.

Center handlers say the baby Persians are about 6 inches long and each weigh only about 1.5 pounds , although none of the center staff has yet handled the animals, the head of the breeding center said in a statement.

Leopard cubs typically stay in their den for about two months, first feeding on partially digested meat from their mother and eventually developing their own hunting skills.

"They will be released into the wild after learning surviving skills, and will start a new population of leopards in the Caucasus Mountains," Natalia Dronova, the World Wildlife Fund's Russian species coordinator, said in a statement.

"It is too early to tell the sex of the cubs. They're in the den with their mother and center staff don't want to disturb them,"said Umar Semyonov, head of the breeding center.

The Persian Leopard Reintroduction Program is run by the Ministry of Natural Resources and Environment of the Russian Federation with participation of the Sochi National Park, Caucasus Nature Reserve, A.N. Severtsov Institute of Ecology and Evolution, WWF and Moscow Zoo.

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