Giraffes had long been thought to be one species with several subspecies, but researchers now believe they have identified six distinct species—some of which are on the brink of extinction, reports the BBC. Only 160 Nigerian giraffes remain. But there's hope the researchers' find will spur greater conservation efforts.
The different kinds of giraffes have wide, overlapping ranges and breed with each other in zoos. Theories vary as to why they don't interbreed in the wild. "The female Maasai giraffe may be looking at the male reticulated giraffe and thinking, 'I don't look like you; I don't want to mate with you,'" a researcher explained.