University of Missouri anthropologist Rob Walker's research uses remote sensing to analyze isolated indigenous societies in the Amazonian rainforests of Brazil.
In a modern world where everyone and everything is connected everywhere, remote regions of the globe still conceal isolated indigenous societies. Now, University of Missouri anthropologist Rob Walker is using innovative technology to explore the threats these people face and analyzing its results for clues to enhance their survival and well-being.
More than 100 isolated indigenous societies, or uncontacted tribes, exist around the world, avoiding sustained contact with outsiders. The majority of these people live in the Amazonian rainforests of Brazil, where between 30 and 50 isolated indigenous societies are estimated to remain.
The small and fragmented societies are threatened by colonization, including large-scale deforestation razing land for agriculture and pasture, and disease, violence and exploitation.
Studying these people is difficult, both for ethical and logistical reasons. Walker and a team of researchers are using remote sensing, employing satellites and sensor technology to detect and examine their lives without physical contact.
His newest research with remote sensing — featuring other researchers — is presented in a December 2023 Scientific Reports (part of the Nature Portfolio journals) article, “Remote sensing evidence for population growth of isolated indigenous societies in Amazonia.”
“Remote sensing provides a safe method to monitor population dynamics of uncontacted populations over time by quantifying their village movements, the area cleared for gardens and villages, the fire detections associated with the burning of these clearings and the number and size of residential structures,” said Walker,an associate professor of anthropology in the College of Arts and Science who joined MU in 2009. “This remote sensing approach uses publicly available satellite imagery combined with deep learning (computer vision) models. Uncontacted indigenous villages, as opposed to other human settlements, have smaller cleared areas, reside at higher elevations and are farther from populated places and satellite-detected lights at night.”
The new work follows Walker and others training machine learning algorithms to identify potential villages.
“Our efforts can improve policies toward isolated populations by providing better near real-time knowledge of their locations and movements in relation to encroaching loggers, settlers and other external threats to their survival,” Walker said.
Learn more about Walker’s research into isolated indigenous societies in this Q&A.
Why focus on isolated indigenous societies for one of your research pursuits?
Uncontacted or isolated indigenous societies actively avoid sustained peaceful contact with the outside world. They are the most traditional of all human cultures, and they are also the most critically endangered. They are fascinating subjects of research because they offer insights into the diversity and resilience of human cultures, languages and ways of life. Knowledge of their locations is essential for urgent protection efforts, but their extreme isolation, small populations and semi-nomadic lifestyles make this a challenging task.
Whether it’s ancient cities in the Amazon, the promise of “The Lost City of Z” or books about the Americas pre-Columbus, Amazonia has long interested people. What draws you to the region?
I was first drawn to Amazonia as an undergraduate student in anthropology when my professor discussed the existence of uncontacted tribes. I still find it absolutely incredible that these tribes exist in today’s world. In our recent paper, we use remote sensing to show that at least one large isolated indigenous population is thriving, but the other smaller populations remain highly vulnerable to external threats.
What are some of the immediate threats and challenges facing indigenous populations in Amazonia?
Last year, the lone surviving man of his tribe for at least 35 years died in Southwest Amazonia, marking the latest cultural extinction event in a long history of massacres, enslavement and epidemics. The colonization of Amazonia by non-indigenous populations has led to catastrophic demographic collapses of indigenous populations. The irreversible threats from large-scale habitat loss via deforestation and conversion of land to agriculture and pasture are now the biggest. Despite the incessant external pressures from the outside world, some remote protected areas in the upper Amazon watershed support isolated indigenous societies.
Large-scale deforestation razing land for agriculture and pasture is one of the chief threats facing isolated indigenous societies in the Amazonian rainforests of Brazil.
How has internal funding — MU Research Council Grants, MU Center for the Humanities Grants, etc. — assisted your research and creative activity?
This internal funding was essential. It allowed me to set up several pilot projects, travel to Brazil and purchase high-resolution satellite imagery. Once I could show a proof-of-concept, it made it much easier to apply for external funding. I was just awarded a Fulbright Scholar Award to return to Brazil for fieldwork over the next two years.
What research opportunities do you provide students, and why is it important to get them involved?
Undergraduate and graduate students have been instrumental in progressing this research. In my Amazon class, we do group projects that use satellite imagery to find and track new uncontacted villages. In the early years, we had to manually comb through imagery. Recently, we’ve been applying more advanced techniques, such as automated object detection with computer vision models, but we will still need students to help with image annotation (drawing bounding boxes) and to sort out model hits as either true or false positives.
What are some next steps in your investigations?
The plan moving forward is to evaluate the prospects for the long-term survival of isolated tribes with remote sensing and understand why some thrive and others do not. This remote sensing approach uses publicly available satellite imagery combined with deep learning (computer vision) models without revealing exact locations. The long-term goal is to help inform policies that enhance the survivorship and well-being of isolated cultural groups. Understanding the population dynamics and growth of these uncontacted groups and the risk of encroachment and incursion by resource extraction is vital for their long-term viability alongside further legal protection.