Just three northern white rhinos are left in the world after the death of a female rhino at a zoo in the United States.
Nola, a 41-year-old female, had to be put down at the San Diego Zoo Safari Park on Sunday. Her health had deteriorated a week or so after surgery to drain a hip abscess. Nola had been a popular attraction at the zoo since 1989.
The remaining three northern white rhinos – all elderly – are kept closely guarded at the Ol Pejeta Conservancy in Kenya. The northern white rhino population was devastated by poachers seeking their prized horns. It was was declared extinct in the wild in 2008.
There are ongoing efforts to try and save the species. San Diego Zoo recently brought in six southern white rhinos, hoping to use them as surrogate mothers for northern white rhino embryos.
There are about 20,000 southern white rhinos in the world.
According to the BBC studies are still taking place to determine whether the southern white rhino is genetically similar enough for the surrogacy to work.
If successful the programme could see a northern white rhino calf born within 10 to 15 years.