“It surprised me very much,” Bataille said of these ranges, which were much larger than he expected. “It will definitely ask a question: Why? What happened? Why did it do this? Why does it move so fast in this way?”
David Nogués-Bravo, associate professor of historical biogeography at the University of Copenhagen, said that signs that mammoths need a very large habitat to thrive can provide us with clues as to why they became extinct. During this mammoth’s life, at some point at the end of the last ice age, the earth was warming. The boreal forest began to take over the mammoth’s home on the prairie. Humans may also have appeared and started hunting them. About 6,000 years after the death of this mammoth, the species was almost extinct. It is difficult for scientists to figure out how different stressors collide to destroy mammoths, but mastering basic data about their habitat range and the extent to which they move around can help them build models to reproduce what might happen.
Nogués-Bravo said that technologies such as isotope mapping are a big step forward because they can help scientists track the process of extinction. “It really opened a big window to help us understand the causes of species extinction,” he said. This can ultimately help scientists predict what might happen to other large animals such as elephants in the next few years as climate change and human disturbance limit their habitat.
However, there is a limit to how fine a picture can be drawn from the data from this ivory. Nogués-Bravo said that these maps may be very accurate in giving where animals are usually located. But they are not GPS. “I am skeptical about the specific route they are trying to simulate,” he said. In order to track these routes, researchers need truly accurate isotope data for every square kilometer of the area, which is a level of detail that their rodent-based maps do not have.
Nevertheless, although the portrait is a bit fuzzy, it is an unprecedented observation of what a mammoth has done in its lifetime. For example, when Wooler and Bataille inspected the roots of ivory, they began to see signs of trouble. The pattern of strontium isotopes indicated that the animal moved less and less, staying in a relatively small area, and did not migrate hundreds of miles as before. Scientists estimate that mammoths can usually live to their 60s or 70s, but this mammoth begins to die when it is only 28 years old. In the last year of his life, the level of nitrogen isotopes in his ivory began to soar, a pattern that indicated that mammals were starving. “It’s like we captured the cause of its death,” Wooler said, although Why It is still a mystery that the mammoth stops moving and eats normally.
Now, researchers want to apply this technique to the ivory of other mammoths. Wooller is curious whether the behavior of other males is similar to what they tracked, and whether the migration pattern of females is different from that of males. He also wanted to know how these movements changed as the earth continued to heat up, so he wanted to examine the ivory of mammoths that lived in different periods. This may provide more clues as to whether their range of activities has changed due to the development of boreal forests or the presence of humans. This technique can also be used on the teeth and antlers of other species that have survived during this period, such as reindeer or musk ox, to understand how each animal responds to this ever-changing world.
“What we are showing here is that a very rich and wonderful record can be obtained from this ivory,” Wooller said. Each is an information library, an entire life story waiting to be read.
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