San Diego Zoo's Northern White Rhino Nola Has Died, Only 3 of Her Kind Remain

Nola, who lived here since 1989, was under veterinary care for a bacterial infection, as well as age-related health issues. In the last 24 hours, Nola's condition worsened and we made the difficult decision to euthanize her

There are only three northern white rhinos left in the world.

On Sunday, the San Diego Zoo Safari Park announced its 41-year-old northern white rhino, Nola, had died. Her passing caused a 25% drop in the Earth’s population of this two-horned subspecies.

According to The Washington Post, Nola was euthanized by zoo officials after the animal became ill from a bacterial infection and her age-related health problems continued to worsen.

“Nola, who lived here since 1989, was under veterinary care for a bacterial infection, as well as age-related health issues. In the last 24 hours, Nola’s condition worsened and we made the difficult decision to euthanize her,” the park said on Facebook. “We’re absolutely devastated by this loss, but resolved to fight even harder to end extinction.”

The continuation of Nola’s kind depends on a trio of older rhinos who live, with 24-hour security surveillance, at Ol Pejeta Conservancy in Kenya. Northern white rhinos have been extinct in the wild since 2008. Scientific procedures are necessary to ensure the survival of this animal. The three remaining rhinos are all too old to breed naturally.

Lenny Ignelzi/AP

But even with human assistance, the likelihood of a new northern white rhino birth, let alone a subspecies comeback, is slim. With the two surviving female rhinos too fragile to carry a pregnancy, researchers, including a group at the San Diego Zoo’s Institute for Conservation Research, are working to develop a rhino IVF procedure where southern white rhinos would carry fertilized northern white rhino eggs to term. Unfortunately, the procedure is a long way from success and researchers only have a finite number of reproductive resources.

If the procedure doesn’t develop, scientists plan to inseminate southern white rhino females with sperm from the northern white rhino males, to preserve some of the ailing subspecies’s traits.

It’s a devastating situation for an animal with no natural predators that once roamed across many regions of Africa. Habitat loss and poaching has decimated this breed, shrinking it’s number from thousands to just four (now three) in a few decades.