High in the Andes of Northern Chile, Hunters Once Used These Stone Wall Traps to Capture Prey

Archaeologist Adrián Oyaneder discovered dozens of structures called chacu while reviewing satellite images of the Camarones River Basin

Sarah Kuta – Daily Correspondent

Archaeologist Adrián Oyaneder was reviewing satellite images of a valley in the Andean highlands of northern Chile when he spotted a series of mysterious, V-shaped structures dotting the landscape. At first, he couldn’t make sense of what he was seeing—and locals living in the area couldn’t identify the structures, either.

But now, Oyaneder has come up with an explanation. The stone wall structures are large animal traps called chacu that hunters used for thousands of years to capture prey animals, he writes in a paper published October 13 in the journal Antiquity.

The presence of the chacu and nearby hunting settlements suggests hunter-gatherers lived in the region much longer than previously thought, from at least 6000 B.C.E. to 1700 C.E., reports the Art Newspaper’s Garry Shaw.

Archaeologists have long assumed that the region’s residents largely stopped hunting and gathering around 2000 B.C.E., as farming and herding took hold. Oyaneder’s findings, however, appear to contradict this narrative, suggesting instead that Andean hunter-gatherers may have lived alongside farmers and herders for thousands of years.

“The picture that emerges is of a landscape occupied by a range of human groups,” Oyaneder says in a statement. “The evidence indicates overlapping lifestyles combining foraging, herding and early agriculture.”

Oyaneder grew up in Chile but now works at the University of Exeter in England. After reviewing satellite photos from the Camarones River Basin, a region that extends from the Pacific coast to the Andean highlands, he ultimately identified 76 chacu, as well as the remnants of nearly 800 nearby shelters and campsites that were likely used by hunters.

The chacu are made up of dry-stone walls that stand roughly five feet high. Each V-shaped structure consists of at least two walls: a longer dominant arm and a shorter secondary arm, each measuring hundreds of feet long. Positioned on steep mountain slopes, the two arms gradually converge before finally emptying into a roughly 1,000-square-foot circular enclosure.

According to Oyaneder, this design funneled animals downhill until they reached a roughly 6.5-foot drop, then fell into the circular enclosure.

This design is not unique to Chile. Chacu have also previously been found in neighboring Peru, and similar structures, known as “desert kites,” have turned up in Saudi Arabia, Jordan and Uzbekistan, according to National Geographic’s Tom Metcalfe. Oyaneder tells the publication that this is an example of “convergence,” which occurs when far-flung groups develop similar techniques and methods independently.

“If you think about the shape of prehistoric fishhooks—you get similar solutions [in different places] depending on the type of fish that you want to catch,” Oyaneder tells National Geographic. “The same happens with these traps. If you have highly elusive animals and a limited number of people, and you want to be selective or not put much effort into it, then this is the solution.”

Oyaneder suspects Andean hunters primarily used the chacu to trap vicuñas, a type of animal related to llamas and alpacas. Ancient rock art appears to support this theory, and Oyaneder notes that the chacu’s elevation above sea level overlaps with the historic habitat of vicuñas.

Fun fact: How big are vicuñas?

As the smallest members of the camel family, vicuñas have a shoulder height of about 36 inches and weigh roughly 110 pounds.Report This Ad

Vicuñas once roamed in large herds across the high Andean plateau. The Inca considered them sacred and collected their soft, warm wool by harmlessly shearing the animals, as Rachel Nuwer reported for Mongabay in 2015. But when Spanish explorers arrived, they began killing vicuñas for their wool.

The population plummeted, reaching a low of around 10,000 individuals in the 1960s. These days, vicuñas are a protected species, but that hasn’t stopped poachers from illegally killing the creatures. In 2018, the International Union for Conservation of Nature estimated that roughly 350,000 mature individuals were living throughout the Andes, and their numbers are increasing.

Oyaneder has visited ten of the newly identified chacu in person. Hoping to find the remains of animals or other historic clues, he’s excavated four of them, but so far he hasn’t found much, per National Geographic. He has also created 3D replicas of the chacu using photogrammetry, and studying these models might reveal additional insights.

In the future, he hopes to train a machine-learning system to search for chacu on satellite photos from other nearby mountain valleys. He suspects chacu are likely widespread across the Andes.

“Prior to my research, fewer than a dozen such traps were known across the entire pre-Hispanic Andes,” he tells the Art Newspaper, adding that he’s already discovered “strong indications” of at least 100 more chacu to the south.