France Media Agency13 Aug 2021 14:29:00 IS
Walking the equivalent of twice around the world in a 28-year life, a woolly mammoth whose footsteps were traced by researchers proved the enormous beast to be a long-distance wanderer.
The results, published Thursday in the prestigious journal Science, could shed light on the theories as to why the mammoth, whose teeth were bigger than a human fist, went extinct.
“In any popular culture – for example, if you watch (the cartoon) ‘Ice Age’ – there are always mammoths that move around a lot,” said Clément Bataille, assistant professor at the University of Ottawa and one of the lead authors of the study.
But there is no clear reason why mammoths would have traveled great distances “because it is such a huge animal that moving around consumes a lot of energy,” he told AFP.
The researchers were stunned by the results: The mammoth they studied likely traveled about 70,000 kilometers (43,500 miles) and did not stay on the Alaskan plains as they had expected.
“We can see that he has traveled all over Alaska, so an immense territory,” said Bataille. “It was really a surprise. “
Readings on a tusk
For their study, the researchers selected the tusks of a male woolly mammoth that lived at the end of the last ice age.
The animal – named “Kik” after a local river – lived relatively near the time of the species’ extinction, about 13,000 years ago.
One of the two tusks was cut in half to measure the strontium isotope ratios.
Strontium is a chemical element similar to limestone and is present in soil. It is transmitted to vegetation and, when ingested, is deposited in bones, teeth… or tusks.
Tusks grow throughout a mammal’s life, with the tip reflecting the early years of life and the base representing the later years.
The isotope ratios are different depending on the geology, and Bataille developed an isotopic map of the region.
By comparing it with the data from the tusks, it was possible to find out when and where the mammoth had been.
At the time, glaciers covered the entire Brooks Mountain Range to the north and the Alaska Range to the south, with the Yukon River Plain in the center.
The animal returned regularly to certain areas, where it could stay for several years. But his movements also changed a lot depending on his age, before he finally died of hunger.
During the first two years of her life, researchers were even able to observe signs of breastfeeding.
“What was really surprising was that after adolescence the isotopic variations start to be much greater,” said Bataille.
The mammoth has “three or four times in its life, made an immense journey of 500, 600 or even 700 kilometers, in a few months”.
Scientists say the male may have been solitary and moved from herd to herd to breed. Or he could have faced a drought or a harsh winter, forcing him to seek a new region where food was more abundant.
Classes for today?
Whether for genetic diversity or because of the scarcity of resources, it is “clear that this species needed an extremely large area” to live, “said Bataille.
But, at the time of the transition from the Ice Age to the Interglacial Age – when they disappeared – “the region shrank because more forests grew” and “humans put a lot of pressure on the south of it. ‘Alaska, where mammoths probably moved much less. “
Understanding the factors that led to the demise of mammoths can help protect other endangered megafauna species, such as caribou or elephants.
With today’s climate change and humans often limiting large species to parks and reserves, Bataille said, “Do we want our children 1,000 years from now to see elephants the same way we see mammoths? today ?