Sudan, last male northern white rhino, dies in Kenya

March 20 (UPI) -- The world's last surviving male northern white rhino died in Kenya, putting the future of the sub-species at risk.

Sudan, the 45-year-old rhino, was put to sleep after suffering from age-related complications that led to degenerative changes in his muscles and bones. The rhino's condition worsened in the last 24 hours, prompting the veterinarian team to euthanize him.

The male rhino's death leaves just two females of his subspecies alive on the planet. Sudan's genetic material was collected before his death -- leaving hope for preserving the northern white rhino in the hands of in vitro fertilization techniques, Ol Pejeta, an African conservatory, said.

"We at Ol Pejeta are all saddened by Sudan's death He was 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," Richard Vigne, Ol Pejeta's CEO, said.

"One day, his demise will hopefully be seen as a seminal moment for conservationists worldwide,"

With five species of rhinoceroses, the white rhino is separated into two subspecies, the southern white rhino, of which 20,000 exist in the wild, and the critically endangered northern white rhino.

The only northern white rhinos left are Sudan's daughter, Najin, and her daughter, Fatu. Both female northern white rhinos remain at Ol Pejeta.

Sudan's death brought tributes from celebrities and world leaders, including Bindi Irwin, the daughter of conservationist and television personality, Steve Irwin.

"Today was heartbreaking for us all as the world says goodbye to Sudan, the last male Northern White Rhino on Earth," Bindi Irwin said in a tweet. "We are sending all our love to the team at Ol Pejeta who have lost part of their family today. Now, more than ever, we must stand together and protect our rhinos."

British Foreign Secretary Boris Johnson also tweeted about the "utter tragedy" of Sudan's death.

"We can't just sit back & watch more species disappear," Johnson said. "UK leading efforts to #endwildlifecrime & will bring world leaders together for talks this autumn."