The world’s last male northern white rhino has died, according to a Kenyan wildlife conservatory and anti-poaching NGO WildAid, spelling the likely extinction for the subspecies.

Kenya’s Ol Pejeta Conservancy announced that 45-year-old Sudan was put down on Monday after battling multiple age-related infections that left him unable to stand. The decision to euthanize Sudan was taken with consultation of Kenyan wildlife officials and representatives from the Dvůr Králové Zoo in the Czech Republic, where he previously lived.

Northern white rhinos used to roam central Africa, with an estimated population of 2,000 in 1960, according to the World Wildlife Fund. But conflict and poaching have driven the subspecies to the brink of extinction in the wild.

Sudan’s death leaves only two northern white rhinos in the world, his daughter Najin, 27, and granddaughter Fatu, 17, who remain at the Ol Pejeta reserve. Though the females were unable to conceive naturally, efforts to save the subspecies have not come to an end.

Last year, Ol Pejeta created a Tinder profile for Sudan in an attempt to draw attention to the species’ plight and raise $9 million to fund an experimental in-vitro fertilization procedure, Reuters reported. The plan would see eggs from the remaining females inseminated with sperm samples from now-deceased males before being implanted in a surrogate female southern white rhino, a related subspecies that still numbers an estimated 20,000, according to WildAid.

“We at Ol Pejeta are all saddened by Sudan’s death. He was an amazing rhino, a great ambassador for his species, and will be remembered for the work he did to raise awareness globally of the plight facing not only rhinos, but also the many thousands of other species facing extinction as a result of unsustainable human activity,” said Ol Pejeta Conservancy CEO Richard Vigne. “One day, his demise will hopefully be seen as a seminal moment for conservationists worldwide.”

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Write to Eli Meixler at eli.meixler@time.com.