Woolly mammoths walked far enough to circle Earth twice, study finds

Study helps reveal vulnerability of species to human encroachment and reminds us of conservation challenges today, writes Harry Cockburn

Isotopes in a 17,000-year-old mammoth tusk revealed where the 28-year-old male had travelled during his lifetime (Getty)

Scientists have recreated the staggering journey made by one Arctic woolly mammoth using samples taken from a 17,000-year-old tusk, revealing, for the first time, that the species travelled “vast distances”.

The research team, which included academics from the University of Ottawa and the University of Alaska, said the breakthrough research provides a new “window into the lives of these now-extinct creatures, including their preferred habitats and extensive lifetime range”.

Until now, mammoths’ home ranges and their mobility, and how far these giant creatures roamed during their lifetimes has remained a mystery.

But fascinating new research, using isotopes which help determine where the mammoth was a t different stages of its life, reveal, “in great detail”,  that this individual travelled routes across a geographically extensive range, with the animal covering enough of the Alaska landscape during its 28 years to almost circle the Earth twice.

The results also illustrate the regions the animal frequented during different life stages, including as an infant and juvenile when part of a herd, as a more broadly traveling prime-aged adult, and during its final years, where, in a small region in northern Alaska, it likely succumbed to starvation.

Clément Bataille, assistant professor of earth and environmental sciences at The University of Ottawa told The Independent that understanding the mobility habits of a species “is key to understanding its vulnerability to external factors”, such as human hunters.

“We know that most of the mammoth population disappeared 12,000 years ago at the transition between glacial and interglacial. We know that this was a time when climate changed dramatically and affected the landscape.

We also know this was a time when first humans were inhabiting Beringia (the area incorporating Alaska and north eastern Siberia in Russia).

“In this context understanding mobility was critical. Was the animal migratory and thus an easy and regular prey for humans? Was the animal moving long-distances and thus sensitive to change in landscape? Those are all questions we wanted to answer.”

In order to do so, Dr Bataille and his colleague Dr Matt Wooller conducted analysis of oxygen and strontium isotopes that had become incorporated into the animal’s tusk during its life.

Strontium isotope ratios in soils and plants reflect the underlying bedrock geology, which vary across landscapes.

As animals eat these plants, particular chemical patterns from the region become incorporated into tissues, which can then be read chronologically, almost laying out a map of where it had travelled.

It took the team, including Dr Amy Willis, a biostatistician at University of Washington, over a year to make the models required to reveal the movements and distances of the mammoth.

She told The Independent: “We found that the mammoth walked approximately 72,000km (44,700 miles) over its 28-year life - that’s around 2,500km per year. For reference, a moderately active human will also walk around 2,000-2,500km per year.”

Speaking about the 28-year-old mammoth tusk they examined, Dr Bataille said they believed when it was young it moved with a maternal herd, probably among the river valleys of interior Alaska.

“In those areas the herd probably moved back and forth seasonally between areas of high and low elevation and between north and south looking for resources,” he said.

As the animal became an adult at around 15 years old, it started to move across the landscape a bit more.

“We argue that because the individual was a male it was possibly because it was kicked out of the herd and started to live a more solitary life. In that stage the individual moved around and did a few long-distance trips.

“These long-distance trips might have been driven by reproduction as this is a behaviour we see in elephants.

“It could also have been driven by resources,” he said.

“Ultimately this particular mammoth moved up north above the Arctic circle and it looks like it got stuck somewhere in the Brooke Range. There it started to slowly starve over a year or two and died there.”

Dr Bataille said for him the most important aspect of the research was the lessons we can learn from history.

He told The Independent: “The Arctic is changing now more dramatically than anywhere else on the planet - impacting its people, plants and animals. Animals are having to alter their ranges and movements in the Arctic in response to global warming. We can learn a lot from the natural environmental change experiments that have occurred in the past to understand how things might play out in the future.

“Did mammoths and other extinct animals change their behaviour in response to the big climate changes that occurred since the end of the last ice age?”

“But before we get to this we need to answer whether woolly mammoths and other extinct animals moved around in the past at all? Did they behave like modern elephants or even caribou that live and move around in the Arctic today? We really didn’t know this.”

He also suggested the demise of mammoths should be read a warning sign for the biodiversity crisis we face today.

He said: “Men have interacted with mammoths for thousands of years. They probably saw them as we see elephants today. A beautiful and majestic animal that is part of their mythology and that made them wonder about the beauty of nature.

“However, in 500 years our grandchildren will possibly see elephants the same way as we see mammoths today. A beautiful species that we contributed to [making] extinct. So I think the extinction of these beautiful and iconic species are important as a wake-up call for humanity.”

The research is published by the American Association for the Advancement of Science.