Experts consider the phrase “uncontacted” to be somewhat inaccurate, as all of the world’s communities have some degree of awareness of their neighbors, as well as a sense of the world that exists outside their homes. Today, about 50 isolated indigenous communities remain across lowland South America, all of which have had limited to no contact with the outside world. Anthropologists stress that while members of such tribes may want to make contact with the outside world, they have chosen not to do so largely because of the fear of being killed or enslaved, and not because of some romantic notion of isolation.

In particular, such uncontacted tribes are extremely vulnerable to disease when they come into contact with the modern world. To take one outstanding example from history, an estimated 100 million indigenous Americans died after Europeans arrived in the Americas in the 15th-16th centuries, felled by diseases the new arrivals brought along with them. In addition, isolated tribes are also vulnerable to exploitation by mining and logging interests, among other modern-day perils. Because of such risks, the Peruvian government bars contact with around a dozen uncontacted Amazonian tribes living within its borders. Brazil, which contains the majority of the world’s remaining uncontacted tribes, has established a governmental agency (FUNAI) that is responsible for indigenous peoples living within the country’s borders. Both these policies are an improvement over the past, when these governments simply refused to acknowledge the tribes’ existence, but some advocacy groups believe they don’t go far enough to protect uncontacted communities and their lands.

In the past, the Mashco Piro tribe has steadfastly resisted the pressures of the outside world. They survived enslavement during Peru’s late 19th-century rubber boom, and later pushed back successfully against missionary efforts. Recently, however, a series of encounters between the Mashco Piro and the outside world has tested the Peruvian government’s “hands-off” policy. According to a report by Reuters, tribe members have appeared in populated areas more than 100 times in the past year, often gesturing to passersby along river banks. In September 2014, the advocacy group Survival International reported that Adventist missionaries left food and clothes intended for the Mashco Piro near the border of Manu National Park, located in the southwestern corner of the Amazon basin.

Some appearances have not been so peaceful. Last May, members of the Mashco Piro attacked a neighboring community, the Machiguenga, and killed a young man with an arrow. In addition, some unscrupulous tour operators are known to offer “human safaris,” in which tourists are promised riverbank glimpses of the Mashco Piro. In an attempt to prevent future violence, and to discourage such unofficial, disorganized contact between tribe members and outsiders, the Peruvian government has decided to establish official contact with the Mashco Piro, despite opposition from groups like Survival International and FENAMAD, a regional indigenous federation, which argue for strict protection of native lands. Government officials tasked with making contact will approach Mashco Piro through interpreters who speak the Yine language, which they believe is similar to the tribe’s native tongue. A team of doctors will be on hand, prepared to treat tribe members if they become ill.

In an article published in Science magazine last month, anthropologists Robert S. Walker and Kim R. Hill argued in favor of such well-organized contacts of isolated tribes. While many of the uncontacted communities in South America had “chosen isolation out of fear of being killed or enslaved,” the researchers argue, “they also wanted outside goods and innovations and positive social interactions with neighbors.” Walker and Hill argue that rather than a hands-off policy from governments, the best course of action is “controlled contact” aimed at preventing the spread of disease, fostering trust between the tribe and the outside authorities, and providing medical and other aid to the tribe members if necessary. If all goes well, the Peruvian government’s mission to contact the Mashco Piro may serve as a test case for such a controlled approach.