Cutting Edge Tech Reveals Bronze Age Migration Routes of Livestock Herders

Using an innovative technique, archaeologists have reconstructed a seasonal migration route herders used in Bronze Age Xinjiang, in China.

A research team from the University of Sydney analyzed three information sources to determine what the northwestern Chinese territory might have looked like more than 3,500 years ago - interviewing modern-day herders still using the area, archaeological evidence, and satellite imagery of the area. With help from the Institute of Archaeology at the Chinese Academy of Social Sciences in Beijing, researchers determined layers of snow cover, as well as the vegetation cycles.

The gathered data were used to create a representative model, with the details behind this effort published in the journal PLOS ONE on Wednesday, November 4.

The Roads Used By Bronze Age Pastoralists

"This detailed model of how Bronze Age people capitalised on the resources in their environment helps greatly in understanding the Prehistoric Silk Road," explained Dr. Peter Jia, lead author of the study from the Department of Archaeology, University of Sydney. He cited that their ethnographic studies, or interviews with local herders, explains the choice for locations. Herders know where early and late grasses would be found, as well as the best grazing sites in summer. It also provided them with the location of clearings in the winter. These accounts from Xinjiang's cattle herders corroborated with satellite data gathered, as well as archaeological surveys and digs in the area.

"From previous archaeological evidence, it was difficult to determine how Bronze Age pastoralists adapted to life in Xinjiang and used the landscape that they settled in," added Alison Betts, co-author of the study, in a press release from the University. "Now we have a new validated method for determining the season in which people stayed in a place."

Seasonal Migration, A Means of Sustenance and Survival

The western Tianshan mountains region is a part of the Eurasian Steppe, or the Great Steppe. Stretching from Xinjiang and covering parts of Kazakhstan, Siberia up to Bulgaria, and Romania in Europe. The main adaptation of humans living in this harsh environment came courtesy of domestication. Even in modern times, the steppes remain an inherently risky place to live in. The seasons are particularly tricky: too much snow leads to a "white disaster" and kills animals with lack of food and vegetation. On the other hand, too little snow and there won't be sufficient water, killing livestock in a "black disaster." Navigating through the steppes to find the optimal place with seasonal migration makes survival of both man and livestock possible.

The accuracy of the findings in the reconstruction of the Bronze Age seasonal migration routes rely on the interdisciplinary approach - modern satellite imagery, archaeological work on the site, and ethnographic data from the modern-day descendants of the people who once used the roads.

Determining vegetation growth cycles, which identified grazing fields, and estimating the depth of snow through satellite technology made it possible to assess different parts of the steppes and analyze how optimal they were for herding across the seasons. Findings from this approach closely corroborated with anecdotal accounts from Kazahk and Mongolian herders.

"This task requires us to connect academic disciplines and cooperate internationally. Our study is a good example of this," said Dr. Gino Caspari, also a co-author of the study.