The northern white rhino, one of the two subspecies of white rhino alongside the southern white rhino, is probably extinct in the wild according to the International Union for Conservation of Nature (IUCN).

Angalifu. Until 14 December, six individuals existed in the world: three at a nature reserve in Kenya, one in the Czech Republic, and two at San Diego Zoo in the United States. That is no longer the case, as the American zoo announced the death, apparently from old age, of Angalifu, a 44-year-old male northern white rhino.

"Angalifu's death is an enormous loss to all of us. Not only because he was very beloved at the park, but also because his death brings the species one step closer to extinction," said Randy Rieches, one of the zoo's curators.

© Cameron Spencer/Getty Images

Only five remain. With his passing, the number of individuals left in the world can be counted on one hand, and the hopes of managing to save the species are now almost nil. At San Diego, Angalifu lived alongside Nola, a female with whom he was unable to reproduce. The same difficulty has been encountered by the three individuals (two females and one male) at the reserve in Kenya, who do not appear to be capable of reproducing naturally.

Rhinos are hunted by poachers for their horn, which is becoming an increasingly sought-after — and therefore valuable — commodity due to its supposed and unfounded medicinal properties. The southern white rhino was also on the brink of extinction. According to WWF, there was a moment in the last century when only 20 remained, but conservation measures put in place brought the population back to around 20,000.

Nella foto in evidenza Angalifu © San Diego Zoo/Helene Hoffman