Six-banded armadillo

Appearance

The six-banded armadillo is the largest in Euphractinae, which also contains the pichi and hairy armadillos; in fact, it is the third largest armadillo after the giant armadillo and the greater long-nosed armadillo. This armadillo is typically between 40 and 50 centimeters in head-and-body length, and weighs 3.2 to 6.5 kilograms . The carapace is pale yellow to reddish brown , marked by scales of equal length, and scantily covered by buff to white bristle-like hairs – unlike the hairy armadillos, that are covered by dense hairs. The shell narrows to 70 to 80 percent of its original width towards the top of the head, which is covered by plates arranged in a definite pattern. The forefeet have five distinct toes, each with moderately developed claws, of which the third is the longest.

Like the other euphractines and the pink fairy armadillo, the six-banded armadillo has a tympanic bulla; the ears are 32 to 47 millimeters long. There are 9 pairs of teeth on the upper jaw and 10 pairs on the lower jaw; the teeth are large and strong and are assisted by strong muscles for chewing. A row of scutes, each 13.5–18.4 millimeters wide, extends along the back of the neck. The tail, 12–24 centimeters long, is covered by two to four bands of plates on the underside. Some of these plates have holes for scent gland secretions, a feature seen in no other armadillo except a few big hairy armadillos.

Naming

The six-banded armadillo is the sole member of the genus ''Euphractus'' and is placed in the family Chlamyphoridae. It was first described by Swedish zoologist Carl Linnaeus as ''Dasypus sexcinctus'' in 1758. The genera ''Chaetophractus'' and ''Zaedyus'' have at times been included in ''Euphractus'', though karyotypical, immunological and morphological analyses oppose this. Fossil ''Euphractus'' excavated in Buenos Aires , Lagoa Santa, Minas Gerais and Tarija date back to the Pleistocene.

The following five subspecies are recognized:

⤷ ''E. s. boliviae'' Thomas, 1907: Occurs in Gran Chaco .
⤷ ''E. s. flavimanus'' Desmarest, 1804: Occurs in Mato Grosso , eastern Paraguay, Uruguay and northeastern Argentina.
⤷ ''E. s. setosus'' Wied, 1826: Occurs in extreme southeastern Brazil.
⤷ ''E. s. sexcinctus'' Linnaeus, 1758: Occurs in southeastern Brazil.
⤷ ''E. s. tucumanus'' Thomas, 1911: Occurs in Catamarca and Tucumán Provinces .



A 2006 morphological study of the phylogeny of armadillos showed that ''Chaetophractus'', ''Chlamyphorus'', ''Euphractus'' and ''Zaedyus'' form a monophyletic clade. The cladogram below is based on this study.

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However, a mitochondrial DNA investigation has concluded that Chlamyphorinae is the sister group of Tolypeutinae , with Euphractinae having diverged earlier.

The six-banded armadillo differs from others in the subfamily Euphractinae, which also contains the pichi and hairy armadillos, in having a narrow head and six to seven movable bands on the carapace . Other names for this armadillo are ' and ' , and 'yellow armadillo'.

Other taxonomists may consider it to be two separate species based on geography, with E. s. sexcinctus, E. s. setosus, and E. s. boliviae treated as Euphractus sexcinctus, while E. s. tucumanus and E. s. flavimanus may be considered a distinct species named Euphractus tucumanus.

Distribution

The six-banded armadillo inhabits savannas, primary and secondary forests, ''cerrado''s, shrublands and deciduous forests. It can adapt to a variety of habitats; it can even occur on agricultural lands and has been recorded at 1,600 meters above the sea level. A study in southeastern Brazil estimated the population density at 0.14 individuals per hectare. The same study showed that the six-banded armadillo often displaces and is displaced by the sympatric southern naked-tail armadillo; this was considered to be helpful in their coexistence. The six-banded armadillo has a wide distribution in South America, from Brazil and southern Suriname in the northeast through Bolivia, Paraguay and Uruguay into northern Argentina in the southeast. Its presence in Peru is doubted.

Reproduction

Breeding behaviour has been observed in captivity. Births take place throughout the year. After a gestational period of 60 to 64 days, a litter of one to three is born. Each newborn weighs 95 to 110 grams , and has a hairless and soft carapace; it can give out soft clicks. The pregnant female builds a nest before giving birth; if disturbed, the mother can react aggressively and shift her offspring. The eyes, closed at birth, open at 22 to 25 days. Weaning occurs at one month and the juveniles mature by nine months. One of the armadillos lived for nearly 18 years.

Food

The six-banded armadillo is an omnivore that feeds on carrion, small invertebrates, insects, ants, fruits , palm nuts and tubers. A 2004 study classified it as a "carnivore-omnivore". In a study in a Brazilian ranch, plant material was found to predominate in the diet. Captive individuals have been observed preying upon large rats. Due to their poor eyesight, armadillos rely on their sense of smell to detect prey and predators. To kill the prey, the armadillo stands on it, grabs it using its teeth and tears it into pieces. Six-banded armadillos can store subcutaneous fat to support themselves at times when food is scarce; this fat can increase the weight to 8 to 11 kilograms .