To save themselves, African elephants are losing their tusks

Tens of thousands of elephants in Africa have been poached for their ivory in the past decade, but some of the jumbos are fighting back in the only way they can: by losing the tusks that expose them to danger.

Evolutionary pressures are favoring elephants with smaller tusks or no tusks at all and so more and more female baby elephants are being born without tusks. Generally, only a mere 4% of female elephants have no tusks, but that percentage has been rising steadily among the pachyderms in Mozambique’s Gorongosa National Park, where a staggering 90% of local elephants have been poached over the past 15 years.

A third of younger female elephants in the park have failed to develop any tusks at all in Gorongosa, where around 4,000 pachyderms lived only decades ago. Following a civil war in 1992 when relentless poaching drove the population of elephants down to a few hundred, the animals started to evolve. Because poachers left female elephants with no tusks alone, these jumbos had a better chance of surviving and giving birth to offspring that inherited their tuskless condition. According to a researcher, of 200 adult females that survived the war in 1992, as many as 51% have no tusks. Meanwhile, a third of female elephants born after the war have no tusks.

“Suddenly tusks become detrimental; they become a liability. So animals that have tusks and therefore have the genes to grow tusks are removed from the population by poachers,” explains Ryan Long, a behavioral ecologist from the University of Idaho. “Animals that don’t have tusks survive because they don’t appeal to the poachers. And so their genes are passed on to the next generation. And you get an increase in the number of individuals that are born without tusks.”

The international trade in illegally trafficked ivory is worth billions of dollars annually and each year up to 30,000 elephants are slaughtered across Africa. Whereas there were 490,000 elephants on the continent a decade ago, there are now only around 350,000. This means that African elephants are being driven ever closer to the edge of critically endangered status across much of their traditional habitats on the continent.

Generally, poachers target male elephants for their more prominent tusks, but once all large males have been killed, the poachers move on to females. That is why elsewhere too in Africa the trend of more and more females being born with no tusks has been observed. In South Africa, for instance, as many as 98% of the 174 females in Addo Elephant National Park had no tusks even more than a decade ago.

“The prevalence of tusklessness in Addo is truly remarkable and underscores the fact that high levels of poaching pressure can do more than just remove individuals from a population,” Long says. “[The] consequences of such dramatic changes in elephant populations are only just beginning to be explored.