A conservation organization in San Diego, California, says it has achieved the first successful artificial insemination birth in North America of a southern white rhino, an important step in saving another rhino subspecies from extinction.

San Diego Zoo Global announced that Victoria gave birth Sunday to a healthy southern white rhino male calf at the San Diego Zoo Safari Park. In the wild, the subspecies lives in Africa.

Artificial insemination is a technique used to allow a female to reproduce without mating. Victoria’s body received sperm from a southern white rhino in March 2018. She carried her calf for more than a year — 493 days. Mother and calf will remain off exhibit to the public for now to allow them time to bond.

“This birth is significant, as it also represents a critical step in our effort to save the northern white rhino from the brink of extinction,” said Barbara Durrant, director of reproductive science at San Diego Zoo Global.

The northern white rhino is a distant relative of the southern white rhino. Only two documented northern white rhinos remain on Earth. Both are female, but sperm from now-deceased males was preserved.

Scientists say the southern white rhinos will eventually be surrogates (carrying babies that are not theirs) for northern white rhino embryos. The reproductive system of rhinos is very complex, but researchers are optimistic that a northern white rhino calf could be born from these processes within 10 to 20 years.

The last male northern white rhino, named Sudan, died in March 2018. Scientists had preserved frozen sperm samples from several males they are hoping to use to revive the species.

Rhinos have long been poached because of their horns, and several subspecies are at risk of extinction. Southern rhinos are classified as near threatened on the International Union for Conservation of Nature Red List of Threatened Species.

Conservationists say rhinos are important for the survival of many other species because of the role they play in landscaping their native habitat.