A 41-year-old northern white rhino died on 22 November at the San Diego Zoo Safari Park in California, leaving just three members of the critically endangered species alive worldwide, zoo officials said.
Nola, who had lived at the California zoo park since 1989, had been receiving treatment for a bacterial infection, according to a statement on the zoo's Facebook page. She was placed under constant veterinary watch last week as her appetite and activity levels declined.
After her condition worsened significantly, caretakers decided to euthanise her, zoo officials said. The three remaining northern white rhinos are at the closely-guarded Ol Pejeta Conservancy in Kenya, the zoo said on Facebook in response to an outpouring of comments from Nola's fans.