Giant armadillos are found across much of northern South America east of the Andes, with the exception of eastern Brazil and Paraguay. In the south, they reach the northernmost provinces of Argentina, including Salta, Formosa, Chaco and Santiago del Estero.
There are no recognized geographic subspecies. They primarily inhabit open habitats, with cerrado grasslands covering about 25% of their range, but can also be found in lowland forests. Hunted throughout its range, a single giant armadillo provides a large amount of meat and is the main source of protein for some indigenous peoples.
Additionally, live giant armadillos are often caught for trade on the black market and invariably die in transit or in captivity. Despite the large range of this species, it is locally rare. This is further exacerbated by habitat loss resulting from deforestation.
Current estimates indicate that the giant armadillo may have experienced a worrying 30 to 50 percent population decline over the past three decades. Without intervention, this trend is likely to continue. The giant armadillo was listed as Vulnerable on the World Conservation Union's Red List in 2002 and is listed on Appendix I (Endangered) of the Convention on International Trade in Endangered Species of Wild Fauna and Flora.
The giant armadillo is protected by law in Colombia, Guyana, Brazil, Argentina, Paraguay, Suriname and Peru, and international trade is prohibited by its inclusion in Appendix I of the Convention on International Trade in Endangered Species.
However, hunting for food and sale on the black market continues to occur throughout its range. Some populations are found in protected reserves, including Brazil's Parque das Emas and Central Suriname Nature Reserve, a massive 1.6 million hectares of pristine rainforest site managed by Conservation International.
Such protection helps to some extent mitigate the threat of habitat loss, but focused conservation action is needed to prevent further decline of this species. Armadillos have not been extensively studied in the wild; therefore, little is known about their natural ecology and behavior.
In the only long-term study of the species, which began in 2003 in the Peruvian Amazon, dozens of other mammal, reptile and bird species were found on the same day in the burrows of giant armadillos, including the rare short-eared dog.
For this reason, the species is considered a habitat engineer and the local extinction of Priodontes can have cascading effects in the mammalian community by depleting the fodder habitat. Furthermore, the giant armadillo was once the key to controlling populations of leafcutters which could destroy crops, but can also damage crops themselves when they dig into the ground.