Why elephants are losing their tusks
In response to the ivory poaching that’s decimating their populations, female elephants are evolving to lose their tusks, reports National Geographic. During the 1977–92 civil war in Mozambique, poachers killed about 90 percent of the elephants in Gorongosa National Park. Today, only about 200 adult females remain—and of those born since the end of the war, 32 percent are tuskless. Usually, only about 4 percent of female African elephants have no tusks. But since tuskless elephants are more likely to survive in an era of heavy poaching, they’re growing in numbers and passing on their genes to tuskless offspring. Among males, tusklessness is extremely rare, but there is evidence that male tusk size is shrinking in response to the ivory trade. In the wake of mass poaching in Kenya during the late 1970s and early 1980s, tusk size in Kenya fell by a fifth in males and a third in females. Elephants that lack tusks—which are essentially overgrown teeth typically used to fell trees, dig holes for water, and do other everyday activities—appear to be adapting and surviving. But they are likely doing so by traveling more to find recoverable food, or by piggybacking off the hard work done by their tusked peers. So it’s unknown how this evolutionary change will affect elephant populations over time, says behavorial ecologist Ryan Long. “[The] consequences of such dramatic changes in elephant populations are only just beginning to be explored.”