High cost of illegal cattle ranching on Indigenous lands in Brazil revealed & rewarded

4 Aug 2025

In June 2024, Mongabay published a yearlong investigation that exposed widespread illegal cattle ranching inside the Arariboia Indigenous Territory in northeastern Maranhão state. The exposé documented how thousands of cattle had been introduced onto Indigenous lands in violation of the Brazilian Constitution. It also revealed the illegal relocation of territorial boundary markers and a surge in environmental crimes in the region, including deforestation and the construction of an unauthorized airstrip. The report, part of Mongabay’s Blood Timber series, drew on satellite imagery, field reporting, and interviews to detail the complex and deadly conditions faced by the Guajajara Indigenous people.

This investigation by reporter Karla Mendes further uncovered a disturbing connection between the illegal ranching boom and a record-high number of killings of Guajajara individuals. In 2023, four Guajajara were killed and three others survived assassination attempts, marking the deadliest year in Arariboia since 2016. Federal prosecutor Alfredo Falcão noted: “The findings show a pattern of targeted killings of the Guajajara amid the expansion of illegal cattle ranching and logging.”

The investigation also highlighted the growing presence of criminals operating at the intersection of illegal cattle ranching and illegal logging in the region. The report identified how these overlapping threats fueled violence and weakened protections for Indigenous communities.

Impact

Following the investigation, Brazilian authorities launched a major enforcement operation in February 2025. Between 1,000 and 2,000 illegally-raised cattle have since been removed. The operation cited Mongabay’s reporting as a critical resource to remove illegal cattle ranching from Arariboia.

“Your report is very similar to what we’re actually finding in the field. It showed an accurate reality and this helped us a lot in practical terms,” said Marcos Kaingang, national secretary for Indigenous territorial rights at the Ministry of Indigenous Peoples. He added that the illegal movement of boundary markers — highlighted in the report — had been verified and was now being corrected by Funai, the federal agency responsible for protecting Indigenous rights in Brazil.

A Federal police raid to tackle illegal logging in Arariboia Indigenous Territory and surroundings. Image courtesy of the Federal Police.
A Federal police raid to tackle illegal logging in Arariboia Indigenous Territory and surroundings. Image courtesy of the Federal Police.

Mongabay’s reporting also is being used in legal proceedings. In addition to the screening of a Mongabay video before Chile’s Supreme Court in early May 2024, the Guajajara referenced the investigation in their request to the Inter-American Commission on Human Rights to protect Arariboia. The Federal Public Ministry aims to use the investigation in the anticipated trial, which will be a legal landmark as the first killing of an Indigenous leader to go before a federal jury.

The report then won the top award for environmental journalism, the John B. Oakes Award for Distinguished Environmental Journalism given annually by Columbia University, and also earned recognition in Brazil: the Blood Timber series received an honorable mention at the Banrisul ARI Journalism Award, which recognizes excellence in journalism in Brazil. It was also a finalist for Brazil’s “I don’t accept corruption” award. 

The report has also been quoted in a book, podcast, and CBC series.

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Banner image: The “Guardians of the Forest” are a group of Indigenous Guajajara in the Arariboia Indigenous Territory who risk their lives to protect their ancestral land against illegal logging, hunting and other environmental crimes. Image by Ingrid Barros for Mongabay.