Before we dive in, a quick note on what “uncontacted” actually means – it’s not about having never encountered another human being from outside of a particular tribe. According to the Indigenous and tribal peoples’ rights organization Survival International, uncontacted tribes are “tribal peoples who avoid contact with outsiders. These could be entire peoples, or sub-groups of larger tribes who do have contact.”

The Mashco Piro

The Mashco Piro are an uncontacted tribe found in remote regions of the Amazon rainforest in south-east Peru. It’s thought that there are over 750 people within the tribe, making it the largest uncontacted tribe left on the planet.

Despite wishing to remain uncontacted, the history of the Mashco Piro is marked by the devastating results of contact. In the late 19th century, their territory was invaded by colonial rubber barons, with land stolen and members of the tribe subject to enslavement, assault, and murder.

While some survived and the tribe lives on today, the Mashco Piro are under increasing threat from logging and deforestation. Some logging companies already operate within the tribe’s territory, while in July 2024, another was spotted setting up shop just a few miles from Mashco Piro land.

The Kawahiva

The Kawahiva live within the Brazilian Amazon, where they live a hunter-gatherer lifestyle. Their diets are known to include animals like peccaries, monkeys, and birds, as well as fruit and nuts from the surrounding forest. Not much else is known about them – just what outsiders have been able to infer from what the tribe has left behind.

Nowadays, they’ve been observed to be nomadic, but it’s thought that wasn’t always the case – deserted clearings suggest they may once have had more permanent settlements. However, the encroachment of logging, ranching, and other destructive activity into their land in Rio Pardo is believed to have resulted seen violence against the tribe. 

Despite attempts at government protection, the remaining Kawahiva peoples are thought to flee from place to place to avoid intruders.

The Sentinelese

The Sentinelese are perhaps one of the most famous uncontacted tribes, although we know very little about them. The tribe – which is thought to consist of around 100 people – resides on North Sentinel Island, a small island in the Indian Ocean.

While uncontacted tribes elsewhere might encounter neighboring peoples, that’s not the case for the Sentinelese, given the isolated nature of a tiny island.

“This makes them the most isolated tribe in the world because they don’t even have neighbors. Most uncontacted tribes have neighbors that they might have some sort of trade with or bump into in the forest, but the Sentinelese really have no one,” Sophie Grig, Senior Research and Advocacy Officer at Survival International, told IFLScience in 2023. “The extent of the isolation with Sentinelese is unique.”

But just because the Sentinelese are isolated doesn’t mean they want to be contacted – something that they’ve made abundantly clear. Outsiders have repeatedly attempted to make contact – even when it was made illegal to go near the island – and have been met with hostility, ranging from members of the tribe drawing their bows as a warning to killing unwelcome visitors.

“They are making a clear choice and a very clear statement to the world that they wish to remain uncontacted and to be left alone,” explained Grig. “No one makes that clearer than the Sentinelese.”