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Elephants are Evolving to Lose their Tusks

There is a study about elephant tusks stating the younger female born after the war never developed their tusks. / Photo by: Getty Images

 

Over more than a century of being hunted and killed by poachers and being slaughtered for their ivory to finance weapons in the country's civil war and meat to feed fighters, elephants are now evolving to not grow their tusks.

The oldest elephants that wander in Mozambique’s Gorongosa National Park are lone survivors of the war that killed about 90% of their kind, bearing the indelible mark of being tuskless.

Tuskless Elephants in Number

Normally, tusklessness only occurs in about two to four percent of female African elephants. However, recent study figures show that about a third of younger females included in the generation born after the war ended in 1992 never developed their tusks.

According to National Geographic, Joyce Poole, an elephant behavior expert and National Geographic Explorer who studies the park’s pachyderms, said that there were some 4,000 elephants that lived in Gorogonsa. However, these numbers sank into triple digits after the civil war. In new, unpublished research Poole had compiled, 51% of the 200 known adult females that are 25 years older are tuskless while 32 % of the females that were born after the war do not have tusks.

Male elephants’ tusk is bigger and heavier than a female of the same age, according to Poole. “But once there’s been heavy poaching pressure on a population, then the poachers start to focus on the older females as well,” explained by the expert. As time goes by, with the older age population, a higher proportion of tuskless females rises.

Based on Mother Nature Network, Poole also found that female elephants without tusks in South Africa experienced an extreme uptick. As of the early 2000s, among 174 female elephants, 98% were tuskless. On the other hand, Josephine Smit, a researcher in the Southern Tanzania Elephant Program and a doctoral candidate at the University of Stirling in Scotland, found that 35% of elephants in Ruaha National Park that are 25 years or older are without tusk, while 13% of the younger population is also tuskless. Aside from this, poaching has also caused the size of the tusk to shrink in some heavily hunted areas, such as southern Kenya, according to Daily Mail.

Since tusklessness is rare in unpoached populations, it is possible then that tusklessness as a trait is being passed down to better ensure the elephants' survival.

The numbers from Poole's research have indicated and illustrated the lasting effect humans have had on animals.

Tusklessness and Its Effect on Elephants

Tusks are overgrown elephant teeth. More than that, elephants use their tusks in a variety of ways as part of their daily living and survival. Tusks aid them in digging for water or vital minerals in the ground, debarking trees to secure fibrous food, and helping males compete for females.

An experiment conducted by Ryan Long, a behavioral ecologist at the University of Idaho, and a team of geneticists and ecologists started tracking six adult females, three with tusks and three without, from different herds to observe the changes of behavior of the elephants. Aside from using GPS trackers, Long together with his colleagues also took blood and stool samples from the elephants. They plan to monitor the elephants until the trackers give out to observe how their genomes are shifting.

Based on their observation, Smit has anecdotally noticed some behavioral changes. According to her, “I've observed tuskless elephants feeding on bark, and they're able to strip bark with their trunks, and sometimes they use their teeth." Tuskless elephants thrive on trees that are easier to strip or trees that have already been slightly stripped. Moreover, the scientists also suggest that there may be other elephants that simply help out their tuskless brethren.

 

Tuskless elephants can be able to feed themselves by using their trunks or teeth when stripping a bark. / Photo by: Viacheslav Nikolaienko via 123rf

 

If elephants change where they live, how fast they move, or where they go, it could have a greater impact on the ecosystems that surround them. “Any or all of these changes in behavior could result in changes to the distribution of elephants across the landscape,” Long also told the National Geographic. Those changes could also result in consequences for the rest of the ecosystem.

The lack of tusks could also affect other wild animals since the work elephants do with their tusks is vital for other animals, too. For example, some lizards prefer to build their houses on trees that elephants have stripped or knocked over, while other animals lean on tusk-dug water holes to feed themselves and for nourishment.

Current prohibitions on trade in ivory in China and the USA can help reduce the demand for tusks, but the length of time for a population with high levels of tusklessness to recover part of their number and their tusk-ness may vary.

On a good note, elephants missing their tusks are surviving and appear healthy despite the wave of human-influenced tusklessness in recent years, according to Poole.

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