Amur leopards, which once roamed across northeastern Russia, parts of China and the Korean peninsula, are so critically endangered that the World Wildlife Fund describes the species as the world’s most rare big cat. Hunted by poachers for its luxurious and beautiful coat, its habitats destroyed by logging, farming and development, the number of Amur leopards remaining in the wild is estimated to be only in the dozens.

The Chicago Zoological Society says there are less than 65 left in the wild in the world, while separate estimates say there are 84 adult Amur leopards and 19 cubs inside a relatively new and massive preserve along the Russian-Chinese border, where the species is struggling to come back from the brink of extinction. Whatever the actual number may be, it’s still critically low, but up from a 2000 census that found just 30 of the big cats.

“Amur leopards are such beautiful animals, and sadly, critically endangered,” Becci May, tigers and Asian species regional manager for the WWF, said in a statement.

“I’ve been very fortunate to go into their forest habitats in Russia and China, and see some fantastic videos images, which provide insights into their worlds. The next few years are really critical for them. Together with governments and other organizations, I feel hopeful that we can help populations to increase as we look to the future.”

Across North America, there are 82 Amur leopards in 42 accredited zoos, according to Chicago Zoological Society. Society officials describe the birth of the two cubs at the Brookfield Zoo as “a crucial addition to the species population.”