Chacoan naked-tailed armadillo (Cabassous chacoensis)

Spanish: Cabasú Chaqueño, Cabasú Chico
GenusCabassous (1)
SizeHead-body length: 300 -306 mm (2)
Tail length: 9 – 9.6 cm (2)

Classified as Near Threatened (NT) on the IUCN Red List (1).

Discovered as recently as 1980 (1), the Chacoan naked-tailed armadillo is the smallest of the four species of naked-tailed armadillo (3). Like other members of the family, the upper surface of this species’ head, body and limbs is armoured with thick bony plates, separated by flexible bands of skin. The Chacoan naked-tailed armadillo’s head is wide, tapering to a short, broad snout (3), and bears small ears with distinctive fleshy borders (4). The upperparts are brown or blackish, while in contrast, the underparts are a dull, yellowish-grey. The claws of the forefeet are long and powerful, particularly the middle claw, which is especially large, and shaped like a sickle. As its name suggests, the tail of this species is not well-armoured, and only possesses a sparse covering of small, thin plates (3).

The Chacoan naked-tailed armadillo is found within the Gran Chaco region of western Paraguay and north-western Argentina (1). A putative specimen was also recorded as originating in the state of Mato Grosso, Brazil, but this is likely to be an error. (4).

The Gran Chaco region comprises a variety of habitats, including forest, savanna, and scrubland (3) (5). While the exact range of habitat types occupied by the Chacoan naked-tailed armadillo is unclear, in Paraguay it has been recorded in undisturbed chaco-seco, an arid shrubland, which is almost desert for nine months of the year (6).

Due to the Chacoan naked-tailed armadillo’s inhospitable habitat it has received very little study (6). It is likely to be entirely nocturnal, spending the day in an underground burrow and emerging at dusk to forage for termites and ants, which it probably locates by scent. This species feeding behaviour is likely to be similar to that of its close relative, the northern naked-tailed armadillo (Cabassous centralis), which uses its large, powerful claws to dig into insect colonies living within dead roots or stumps, and employs its long, extensible tongue to probe tunnels within the colony and extract its prey (3). Naked-tailed armadillos move with a characteristic waddling gait, with the hindfeet directed inward and the front of the body supported on the tips of the foreclaws (4).

In the wild, naked-tailed armadillos are believed to be solitary, although in captivity individuals will tolerate living in close proximity (3).

Currently, the main threats to the Chacoan naked-tailed armadillo are habitat degradation resulting from agricultural expansion, and subsistence hunting by local people. Due to a lack of population surveys, it is unclear to what degree this species’ population is being affected, but over the past decade, declines of between 20 and 25 percent have been proposed (1) (6).

While there are no known conservation initiatives specifically targeting the Chacoan naked-tailed armadillo, it has been recorded in several protected areas, including the Parque Nacional Río Pilcomayo, Parque Nacional Copo and Reserva Natural Formosa in Argentina, and the Parque Nacional Defensores del Chaco in Paraguay (1) (6). Despite this protection, detailed study of the Chacoan naked-tailed armadillo’s population and biology is still required in order to determine whether specific action needs to be taken to conserve this remarkable species (6).

To learn more about conservation initiatives within the Chacoan naked-tailed armadillo’s habitat visit:

Authenticated (04/09/2009) by Dr. Mariella Superina, Chair of the IUCN/SSC Anteaters, Sloths and Armadillos Specialist Group.

  1. IUCN Red List (March, 2009)
  2. Eisenberg, J.F. and Redford, K.H. (1992) Mammals of the Neotropics: The Southern Cone: Chile, Argentina, Uruguay, Paraguay. University of Chicago Press, Chicago.
  3. Nowak, R.M. (1999) Walker's Mammals of the World: Volume 2. Johns Hopkins University Press, Baltimore, Maryland.
  4. Wetzel, R.M. (1980) Revision of the naked-tailed armadillos, Genus Cabassous McMurtrie. Annals of Carnegie Museum, 49: 323 - 357.
  5. The Nature Conservancy (March, 2009)
  6. Da Fonseca, G.A.B. and Aguiar, J.M. (2004) The 2004 edentate species assessment workshop. Edentata, 6: 1 - 26.