Tracing the movements of a 17,000-year-old woolly mammoth is a remarkable feat in the field of paleontology. Woolly mammoth, ancient elephant relatives, roamed the Alaskan wilderness during the Ice Age around 17,100 years ago. What’s even more astonishing is that mammoths were world-travelers.
These colossal creatures, with adult males standing at a towering 12 feet tall, boasted thick skin, dense fur, and tusks that could reach up to 12 feet in length. No predator could take down an adult mammoth, but young mammoths, around four feet tall, fell prey to saber-toothed cats.
The Journey Begins with Ivory
The scientists’ journey to trace mammoth migration started with an idea from Matthew Wooller, an isotope specialist at the University of Alaska Fairbanks. In 2015, he noticed a graduate student examining fish otoliths, small ear bones that add new layers every year, preserving chemical information about the fish’s life and habitat.
Wooller’s fascination with mammoths grew after studying their extinction on St. Paul Island in the Bering Sea. He compared mammoth tusks to diaries written in ivory. “Each day, it adds a new layer, and these layers pile up like scoops of ice cream,” he explained. The isotopes in these layers recorded where the animal had been and what it had eaten on that day.
Isotopes Tell the Tale
Isotopes are atoms of the same chemical element with different weights, and they are found in various environmental elements like rocks, soil, plants, and water. Living creatures incorporate these isotopes, and different locations have distinct isotopic signatures. This allows scientists to track mammoth migrations by analyzing the isotopes in their ivory.
Cracking the Mammoth’s Ivory Code
In 2016, Wooller launched this project by selecting one of the 174 woolly mammoth tusks collected in Northern Alaska by university researchers in 2010. Radiocarbon dating and genetic testing confirmed that the mammoth, named Kik after Kikiakrorak, was a male who died approximately 17,100 years ago.
The next challenge was physically splitting the mammoth tusk, weighing over 500 pounds, into two parts. Once successfully divided, the tusks were sent to a laboratory for further analysis. Each half of the tusk, measuring five and a half feet in length, revealed the mammoth’s growth layers.
Mapping Mammoth’s Journey
To analyze the mammoth ivory’s isotopes, scientists used a sophisticated scientific instrument called a multi-collector laser ablation inductively coupled plasma mass spectrometer. This instrument rolled a laser across each section of the mammoth tusk, turning a tiny portion into fine dust, which was then subjected to isotopic analysis.
The instrument generated over 400,000 data points that helped map the mammoth’s journey. Additionally, the team utilized information from rodents and other small mammals collected from all over Alaska. Strontium isotopes in these rodents’ teeth provided geological information about their locations.
By analyzing strontium in 162 rodent specimens, the team created a strontium map of Alaska, aiding in understanding the mammoths’ environment and movements.
Unraveling the Past
The findings provided a deep insight into the woolly mammoth’s journey. Through the ivory’s isotopic analysis, Matthew Wooller and his team were able to track Kik’s travels from northern Alaska to the Brooks Range. This information offers a detailed glimpse into Kik’s life history, suggesting that he left his matriarchal herd for a long-distance journey before eventually succumbing to starvation.
Kik’s mammoth ivory provides a comprehensive account of his life. Through isotopic analysis, scientists have unveiled the epic odyssey of Kik, who embarked on his journey during the Last Glacial Maximum, a period marking the late Pleistocene, around 20,000 years ago. During this time, glaciers covered about 25% of the Earth’s land area, and the global sea level was approximately 400 feet lower than today.
