LOS ANGELES • A northern white rhinoceros, one of just four left on earth, has died at the San Diego Zoo Safari Park after suffering from a bacterial infection and age-related health issues.

Zoo officials said Nola, a 41-year-old rhino brought to the Southern California park in 1989 as part of a breeding programme, took a turn for the worse over the weekend following a Nov 13 surgical procedure to drain a large pelvic abscess identified as the infection source, the zoo said in a statement.

The 1,800kg rhino had been placed under constant veterinary watch last week as its appetite and activity levels declined. After its condition deteriorated significantly, caretakers decided to euthanise the female rhino on Sunday, zoo officials said.

"Nola was an iconic animal, not only at the San Diego Zoo Safari Park, but worldwide," the zoo said. "Through the years, millions of people learnt about Nola and the plight of rhinos in the wild through visits to the Safari Park, numerous media stories and social media posts."

Northern white rhinos were declared extinct in the wild in 2008 because of poaching for their horns, prized on the black market for their supposed medicinal properties in some cultures.

Nola was the only member of its kind left in captivity in the Western Hemisphere. With its death, just three others remain, all at the Ol Pejeta Conservancy in Kenya, zoo officials said.

Nola was born in the wild in Sudan and captured at about two years old, according to the San Diego Union-Tribune. It arrived in California from a Czech zoo.

Nola's death came weeks after six southern white rhinos, close cousins of northern whites, were brought to San Diego from South Africa in an effort to bring Nola's kind back from the brink of extinction.

REUTERS