OL PEJETA CONSERVANCY, Kenya — It's not that Sudan didn't want a baby. Researchers had watched the 42-year-old northern white rhinoceros try to mount a female. Rangers had seen him stare across the enclosure at the ladies "admiringly," sharpening his horn as if he was preparing to win them over.
But age had caught up with him. His hind legs were weak. The quality of his sperm was poor. And as the odds dimmed that he would mate successfully, conservationists had to reckon with their own failure.
How had the fate of an entire subspecies of rhinoceros been left to one elderly male?
In just a few decades, a large population of northern white males has been reduced to a single 3,500-pound bull living in a 10-acre enclosure with round-the-clock guards. There are also four females left: two in Kenya and one each in the United States and the Czech Republic. But none is fertile, meaning the population is on the verge of extinction.
Even as the world's wildlife faces increasing threats — a surge in poaching, the loss of native habitats — extinction is still often discussed as an abstraction. It's a word used often to prompt action — something that could happen.
But scientists estimate that hundreds — perhaps thousands — of species are becoming extinct each year. In 2011, the western black rhino was classified as extinct. That same year, a subspecies of the Javan rhino was declared extinct in Vietnam. And barring a scientific breakthrough, the northern white rhino, the second-largest mammal in central Africa, will be gone soon, too.
"It's a massive conservation failure," said Richard Vigne, chief executive of Ol Pejeta Conservancy, the private wildlife refuge where the white rhinos now live.
When Sudan was born in 1972 in what is now South Sudan, there were about a thousand northern white rhinos scattered across central Africa. They were concentrated in countries plagued by war: Sudan, Congo, the Central African Republic. When fighting broke out, the rhinos were also victims, killed for their meat or horns, or sometimes exchanged for money or arms.