A northern white rhinoceros named Nola was put down at the San Diego Zoo Safari Park on Sunday. With Nola's death, there are now only three northern white rhinos left on Earth, all living in the Ol Pejeta Conservancy in Kenya.
The 41-year-old rhino had been suffering from a bacterial infection and age-related health issues, the San Diego Union-Tribune reports.
The San Diego Zoo Safari issued this tweet after Nola's death:
The northern white rhino, a subspecies of white rhino, has been extinct in the wild since 2008, The Washington Post reports. The newspaper adds:
"They're among the largest land animals on Earth, second only to elephants. They can run at speeds of more than 30 miles per hour and their horns, tough skin and sheer size mean they have no natural predators. ...
"Civil war, habitat loss and poaching for their valuable horns decimated the rare breed; between 1960 and 2015 the population fell from 2,000 to five."
Attempts at natural breeding have failed, but there are efforts to try to breed another northern white rhino through in vitro fertilization. According to Live Science, however, no one has ever successfully conducted the procedure on a rhinoceros.
As NPR's Gregory Warner reported last year, there have been examples of epic comebacks in the rhino community. At one point, the southern white rhino was on the verge of extinction:
"At the turn of the 20th century, southern white rhinos had been hunted down to a mere 20 animals. The last of the southerns were collected, protected and bred. Now they number more than 14,000."
Why does the outcome for northern white rhinos appear headed in the opposite direction? Warner explains:
"The southern white rhino attempts began when the animals were younger. They were also wilder. One hundred years ago, when those 20 last southern white rhinos were collected and bred, they were taken straight from the savanna, not from a zoo.
Perhaps what enabled them to breed is that little bit of wildness that never left them."