High in the remote Andean highlands of northern Chile, a landscape once thought to be sparsely occupied has revealed a vast and sophisticated network of ancient hunting structures. An archaeologist, using publicly available satellite imagery, has identified 76 massive, funnel-shaped stone traps known as “chacus,” which were designed to capture wild camelids. The discovery challenges long-held theories about the region’s history, suggesting that hunter-gatherer practices did not fade with the rise of agriculture but instead persisted as a vital part of life for millennia, possibly into the 18th century.
The research, published in the journal Antiquity, fundamentally reshapes the understanding of pre-Hispanic life in the Camarones River Basin. Alongside the 76 chacu traps, the study also uncovered nearly 800 previously unknown small-scale settlements, indicating a landscape actively used by mobile populations. These findings suggest that for thousands of years, communities skillfully combined foraging, herding, and early agriculture in a complex, overlapping system of survival, a far cry from the previously accepted linear progression from hunting to farming.
New Views from a Higher Altitude
The breakthrough came from a methodical, high-tech survey of a region that has received little archaeological attention. Dr. Adrián Oyaneder, an archaeologist at the University of Exeter, examined 4,600 square kilometers of the Camarones River Basin from his desk, scrutinizing satellite data of the remote, high-altitude terrain. Over a period of just four months, this remote sensing work allowed him to identify hundreds of potential archaeological sites that were largely invisible from the ground.
This modern approach to archaeology proved exceptionally effective for the rugged and difficult-to-access Andean highlands. Oyaneder’s work demonstrates the power of using publicly accessible satellite imagery and Geographic Information Systems (GIS) to survey vast areas efficiently. The initial discovery of one chacu led to the realization that these structures were not isolated anomalies but a widespread and integral feature of the highland landscape, a quantity never before recorded in the Andes.
The Architecture of a Communal Hunt
The design of the chacus reveals a sophisticated understanding of animal behavior and landscape topography. Most of the traps consist of two long, dry-stone walls, typically about 1.5 meters high, that form a V-shape or funnel. These walls, sometimes stretching for hundreds of meters, were built to guide herds of vicuña—a wild relative of the alpaca—downhill. Many were strategically constructed on steep slopes, using natural features of the terrain to enhance the funneling effect.
Engineered for Efficiency
The structure’s arms were not uniform in size; on average, a dominant arm would extend for about 181 meters, with a shorter one measuring around 97 meters. As animals were driven from higher ground into the narrowing space between the walls, they were forced toward a drop, typically two meters deep, where they would fall into an enclosure. This design allowed communities to capture animals on a large scale, likely through coordinated, communal efforts.
A Global Connection
This architectural pattern is not unique to South America. Researchers noted a strong resemblance to so-called “desert kites” that have been documented in arid regions like the Black Desert of Jordan. The striking formal and functional similarities suggest a convergent evolution of hunting strategies in similar environments across the globe. The concentration and complexity of the Chilean chacus, however, provide new insight into their use in the Andes, with evidence suggesting they may predate the well-known traps used by the Inka empire.
A Landscape Dotted with Settlements
The discovery of the hunting traps was accompanied by another significant finding: the identification of nearly 800 small-scale settlements scattered across the surveyed area. These habitation sites vary widely in size, from single, one-square-meter buildings to more complex clusters of nine or more structures. Their close proximity to the chacus provides strong evidence of a connected and mobile way of life centered around the region’s primary hunting resources.
Using GIS mapping, Oyaneder found that these settlements were often grouped in clusters and located within a 5-kilometer radius of the hunting traps and other habitation sites. This spatial relationship suggests a network of short-term, seasonal camps and outposts. These smaller sites likely allowed groups to move strategically across the rugged terrain, following the vicuña herds and utilizing different areas of the highlands as resources became available.
Challenging a Long-Held Timeline
Perhaps the most profound implication of the discovery is its challenge to the established timeline of human subsistence in South America. For decades, the prevailing archaeological model suggested a gradual but steady decline in hunting and gathering practices starting around 2000 B.C., as domesticated plants and animals became more widespread and societies transitioned to agropastoralism. It was widely believed that by 650 A.D., farming and herding had largely replaced the hunter-gatherer lifestyle in this part of the Andes.
The vast network of chacus and associated settlements provides compelling evidence to the contrary. The research indicates that hunting and foraging remained central aspects of community life from as early as 8000 B.C. all the way through the 18th century. Rather than being replaced, these ancient practices appear to have coexisted with herding and farming, creating a flexible and resilient economic system. This new understanding aligns better with certain historical sources, such as Spanish colonial tax records, which referred to foraging populations known as “Uru” or “Uro” in the region, long after they were thought to have disappeared.
A Researcher’s Perspective
The sheer scale of the find was surprising even to the lead researcher. “Prior to my research, fewer than a dozen such traps were known across the entire pre-Hispanic Andes,” Adrián Oyaneder stated, noting that his work, in parallel with a French research team, has now documented 76 examples in the Camarones Valley alone. He described his initial reaction to seeing the first chacu on the satellite imagery as one of disbelief, prompting him to double and even triple-check the finding before realizing they were a common feature of the landscape.
According to Oyaneder, the evidence paints a picture of a dynamic landscape occupied by various human groups for millennia. “These groups moved strategically across the highlands, tethered primarily to hunting resources, particularly vicuña,” he explained. The discoveries reveal a complex tapestry of overlapping lifestyles, where mobile hunting parties and settled pastoralists shared the same high-altitude environment, each contributing to a diverse and enduring cultural presence in the Andes.