Tuskless elephants thrive, avoid poaching
Ultra-valuable ivory makes other females worth $100K each
ADDO, South Africa — Through the narrow slit of the underground hide in front of the water hole, an African morning revealed itself. The sun painted the earth orange. A lion stepped out of the bush and a small herd of perfectly camouflaged kudus, a large antelope-like animal, started and bolted away.
Soon a single bull elephant appeared where the lion had been, shaking his head as if scanning the bush. After a while, five female elephants descended the orange hillside to drink.
Even from a distance it was easy to tell they were females; in South Africa’s Addo Elephant National Park, they are almost always the ones without tusks.
In most African elephant populations, as few as 2 percent of the cows lack tusks. But among Addo’s 300-odd females, the rate is 90 percent to 95 percent, a trait that has evolved rapidly over the last century.
And at least partly as a result, Addo’s elephants also have been spared something else: poaching.
“Addo elephants might be the biggest success story anywhere,” said the park’s conservation manager, John Adendorff. “So maybe it’s not a bad thing that they don’t have tusks. Tusklessness has helped protect them.”
Although scientists have not worked out the genetics, the absence of tusks appears to be a sex-linked trait and rarely occurs among males, except through injury.
A 50-year-old bull can grow tusks as heavy as108 pounds each. With a world ivory price in the range of $1,000 per kilogram, that’s a nearly $100,000 payday for poachers.
Anna M. Whitehouse, an elephant expert who has studied the Addo population for many years, said the number of tuskless elephants increased steadily after the park was founded in 1931, reaching 98 percent by the early 2000s. All of them descended from 11 elephants left after a hunter wiped out more than 100 at the park.
But Whitehouse attributed that to inbreeding among the small number of animals, a phenomenon known as “genetic drift,” rather than because of natural selection due to poaching.
Male elephants use tusks to fight other males for access to females, and to guard their family herds. Protecting the tuskless females seems to be the reason bull elephants often come first to the water holes in Addo.
But tusks are also tools for gathering food, digging for water and fending off predators, so cows need them as well.
Nonetheless, the absence of tusks does not seem to have hurt the Addo elephant population much. It has been doubling once every 13 years and now numbers more than 600.
“Maybe tusklessness is the future,” said Michael Paxton, a ranger who is a veteran of poacher wars in South Africa’s Kruger National Park. “Our cows have gone a hundred years without tusks and they’ve done OK.”