The municipal government of Santa Cruz, Bolivia, is reviewing a proposal to give “natural patrimony” status to the greater fairy armadillo (Calyptophractus retusus), a rare type of armadillo that has a flexible shell, the ability to live underground, and an unfortunate reputation.

The goal of the proposal, pushed by researchers, is to ensure protection of the habitat of the mammal, known as the culotapado or coseberu. In 164 years, there have been only 25 official sightings of the greater fairy armadillo in the dry, sandy terrain it inhabits in a corner of the Chaco region in southern Bolivia, northeast Paraguay and northern Argentina. There, the small, pink-colored creature tunnels for insects, its main source of food. It is a prodigious excavator, able to completely bury itself in seconds to hide from predators such as foxes and owls.

Since its first recorded capture in the Bolivian province of Andrés Ibáñez in 1859, the animal has received little scientific study. That’s mainly because of its small size—the armadillo measures just 17 centimeters when fully grown—as well as its nocturnal lifestyle and tendency to live underground.

Development pressure

The province of Andrés Ibáñez grew urbanized over the past century; its capital, Santa Cruz, is home to 1.65 million people. The trend has put increasing pressure on wildlife of many types, the greater fairy armadillo included. “In recent years there has been a constant threat to [the armadillo’s] population due to urbanization, the introduction of dogs and cats, floods, and deforestation associated with ranching and farming,” says Huáscar Bustillos, a biologist at Gabriel René Moreno Autonomous University in Santa Cruz.

Another threat is a belief among some of the Chaco’s Indigenous Guaraní people that the homely looking armadillo, which can emit a sound akin to a baby’s wail, is a harbinger of death. Often accompanying that belief is the view that whenever the tiny armadillo is seen, it must be killed and burned.

Until 2010 the greater fairy armadillo was classified as “near threatened” by the International Union for Conservation of Nature (IUCN). But since then it has been listed as “data deficient” owing to a lack of data to describe its status. Indeed, little is known about its reproductive cycle, lifespan, and food preferences, among other things. The animal is presumed to avoid predators such as foxes and felines not only due to its digging ability, but also to its shell’s light-pink hue, which helps it blend into the arid Chaco landscape.

Bustillos says that by living almost permanently underground, the greater fairy armadillo “plays a great role as a controller and regulator of populations of the insects [such as ants, termites, and crickets] and worms that it feeds on.” Bustillos notes the animal performs underground seed dispersal and “contributes to aeration and interchange of oxygen and nutrients in the soil when it creates its tunnels.”

The diminutive armadillo’s popular name, “culotapado,” is inspired by the animal’s blunt posterior. Another unusual characteristic is its spatula-like tail, which experts say it uses for stability while digging to hide or find insects.

Populations of the armadillo in Bolivia’s Kaa-Iya del Gran Chaco National Park and Integrated Management Natural Area have legally protected status. But no such protections apply to greater fairy armadillos living in the grasslands near Santa Cruz, in the dry Chaco ecosystems of southeast Bolivia, or in sandy areas near the Piray River.

Rare encounter

Bustillos, an authority on the greater fairy armadillo, has seen the animal in an active, healthy state just once—in 2020. A farmer driving at night spotted one of the armadillos wandering and seemingly disoriented on a roadway west of Santa Cruz, so he stopped and picked it up. He took it to his house and searched the internet with his wife to determine its species.

They soon found articles by Bustillos, and contacted him. The biologist came to their house the next day with other specialists to view the animal, whose official sightings since 1859 have numbered 12 in Bolivia, three in northern Argentina, and eight in Paraguay—two of the latter in Paraguay’s Teniente Agripino Enciso National Park.

Bustillos was able to confirm firsthand that the armadillo’s shell was soft and flexible, one of its main distinguishing characteristics compared with other armadillo species. This feature, he says, allows the animal to “dive into the sand and waddle, as if it were swimming.” The front legs, Bustillos adds, “are extremely large, muscular, and strong.”

The armadillo found by the farmer was freed soon after being examined by the scientists. The confirmed sighting of it prompted public discussion on the need to determine the impacts that factors such as urbanization and flooding are having on its prospects for survival.

“Legislation is needed to put it in a category of greater conservation status and promote research of this animal that is so closely associated with Bolivia and Santa Cruz, where it was seen for the first time in 1859,” Bustillos says.