No one told them to cross the border. No helicopter transported them. No conservation team moved them in crates. The giant anteaters simply walked — following something deep inside them — back into southern Brazil, where their species had been extinct for 130 years. The moment they crossed from Argentina is one of conservation's most quietly extraordinary stories.
The story begins in 2007, when Rewilding Argentina — an offshoot of Tompkins Conservation, the organisation founded by the late Patagonia founder Doug Tompkins — began reintroducing giant anteaters to Argentina's Iberá wetlands. Over nearly two decades, approximately 110 giant anteaters were released into Iberá National Park. They didn't just survive — they thrived. By 2022, hundreds of animals were living across five population centres within the wetlands, with two of those populations becoming fully self-sustaining.
Beginning in August 2023, something remarkable was confirmed: giant anteaters from the Iberá population were being spotted in the Rio Grande do Sul state of southern Brazil — a region where the species had been considered extinct for more than a century. These weren't stray individuals lost in unfamiliar territory. The sightings have been recorded multiple times since, suggesting a genuine, sustained expansion of the population into its former range.
The animals were not introduced to Brazil. They dispersed there naturally, following ecological corridors that allow wildlife to move across political borders that mean nothing to them. In doing so, they restored a connection between two ecosystems that had been severed for generations.
Giant anteaters (Myrmecophaga tridactyla) are ecological engineers. Each animal consumes up to 35,000 ants and termites per day, controlling insect populations across vast areas. Their powerful digging creates temporary watering holes that benefit dozens of other species. When anteaters disappear from an ecosystem, the ripple effects touch everything from soil health to plant diversity.
The health of the Iberá population was further demonstrated in July 2024, when giant anteater twins were recorded in the wetlands for the first time in Argentina — an exceptionally rare event. That it happened is a sign of a population with the numbers, habitat, and stability to support even rare biological events.
That's what rewilding looks like when it works. 🐜
*Sources: Rewilding Argentina / Tompkins Conservation · Mongabay · rewilding.org*
