The northern white rhinoceros is one step closer to extinction, after a 41-year-old female at a zoo in the United States was put down on Sunday.



Nola was one of the world's last four remaining northern white rhinos, and had been a favourite with zookeepers and the public at the San Diego Zoo Safari Park since 1989.

She underwent surgery on 13 November to drain a hip abscess, but her health began to deteriorate after the operation. Nola was euthanised early on Sunday, after her condition worsened significantly.

"Nola was an iconic animal. Through the years, millions of people learned about Nola and the plight of rhinos in the wild through visits to the safari park," the zoo said in a statement.

"We're absolutely devastated by this loss, but resolved to fight even harder to #EndExtinction. We ask that you join us in that fight."

The northern white rhino was declared extinct in the wild in 2008, and the last three animals in captivity live at the Ol Pejeta Conservancy in Kenya, where they are closely guarded.

The San Diego Zoo is developing a surrogacy programme, hoping to use southern white rhinos as surrogate mothers for northern white rhino embryos in an attempt to recover the species.

Rhino populations have been decimated by poachers seeking their prized horns, and there are only about 20,000 southern white rhinos remaining in the world.