The first study to document the annual migration of an individual animal from an extinct species was done around 13,200 years ago when a mastodon died in a battle with a rival.
When the animal's remains were recovered from a peat farm near Fort Wayne in 1998, they discovered a mortal wound on the right side of the animal's skull.
During the last three years of his life, this solitary rambler made the trek annually from his cold-season home to Northeast Indiana to mate, according to a paper scheduled for online publication in June.
A full-size fiberglass-cast skeleton of the bull is on display at the University of Michigan Museum of Natural History.
"For the first time, we have been able to document the annual overland migration of an individual from an extinct species," said University of Cincinnati paleoecologist Joshua Miller.
We have been able to show that large male mastodons like Buesching migrate every year to the mating grounds.
Daniel Fisher was involved in the excavation of mastodons. He used a bandsaw to cut a thin slab from the center of the animal's banana-shaped right tusk, which is more complete and long than the left one.
Scientists were able to reconstruct changing patterns of landscape use during two key periods: adolescence and the final years of adulthood using that slab. According to the researchers, the mastodon died in a fight over access to mates.
Fisher has been studying mastodons and mammoths for more than 40 years and helped excavate several dozen of the extinct elephant relatives.
The growth and development of the animal, as well as its history of changing land use and changing behavior, is recorded in the structure and composition of the tusk.
The team found that the original home range of the mastodon was in central Indiana. Like modern-day elephants, the young male stayed close to home until he was old enough to leave the herd.
According to the researchers, as a lone adult, he traveled far and frequently. A dramatic northward expansion into a summer only region that included parts of northeastern Indiana was one of his landscape uses.
The mastodon would go to the same place every time it got warm. Miller said that the clarity of the signal was unexpected and really exciting.
The reproductive success of mastodons and other large mammals may have depended on migration and other seasonal patterns of landscape use. According to the new study, little is known about how their geographic ranges and mobility changed as they got older.
Some of the secrets of the elements strontium and oxygen are being unlocked by using techniques to analyze their ratios.
Mastodons, mammoths and modern elephants, which are part of a group of large, flexible-trunked mammals called proboscideans, have teeth that come from their skulls. The growth layers are laid down in alternating light and dark bands.
The yearly growth layers in a tusk are similar to a tree's annual rings, except that each new tusk layer forms near the center, while new growth in trees occurs in a layer of cells next to the bark. The time of death is recorded at the base and the time of birth is recorded at the tip.
Mastodons used to browse on trees and shrubs. Chemical elements in their food and drinking water were incorporated into their bodies as they grew.
The researchers were able to reconstruct Buesching's travels as an adolescent and as a reproductively active adult with the help of strontium and oxygen. Thirty-six samples were taken from the adolescent years and 30 from the final years of the animal's life.
A drill bit was used to grind half a millimeter from the edge of individual growth layers, each covering a period of one to two months in the animal's life. During this milling process, the powder was collected and analyzed
The ratio of strontium in the tusk gave geographic fingerprints that were matched to specific locations on maps showing how strontium changes. The researchers were able to determine the time of year with the help of oxygen isotope values.
Because both strontium and oxygen isotope samples were collected from the same narrow growth layers, the researchers were able to reach specific conclusions about where he traveled and how old he was.
Miller and his colleagues created a movement model based on the data from the tusks. The model made it possible for the team to estimate how far the animal was moving and the probability of movement between candidate locations.
Paleontology, archaeology, historical ecology, and even forensic biology are some of the uses of the field of strontium isotopegeochemistry. Miller said it was flourishing. We have just begun to understand what this information can tell us.
The next step in the mastodon research project is to analyze the tusks of a male or female.
The University of Cincinnati, the Nebraska State Museum and the University of Nebraska-Lincoln are where the other authors are from.
More information: Male mastodon landscape use changed with maturation (late Pleistocene, North America), Proceedings of the National Academy of Sciences (2022). DOI: 10.1073/pnas.2118329119. Journal information: Proceedings of the National Academy of Sciences
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