Chaetophractus vellerosus (Gray, 1865)

Russell A. Mittermeier & Don E. Wilson, 2018, Chlamyphoridae, Handbook of the Mammals of the World – Volume 8 Insectivores, Sloths and Colugos, Barcelona: Lynx Edicions, pp. 48-71 : 67-68

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Screaming Hairy Armadillo

Chaetophractus vellerosus

French: Petit Tatou / German: WeilthaarGurteltier / Spanish: Piche llorén

Other common names: Lesser Hairy Armadillo, Small Hairy Armadillo; Andean Hairy Armadillo (nationi)

Taxonomy. Dasypus vellerosus Gray, 1865 ,

“Santa Cruz de la Sierra,” Santa Cruz, Bo- livia .

Recent studies of hairy armadillos using morphological and molecular analyses re- vealed that there are insufficient differences between C. nation: from Andean Bolivia, northern Chile, and northern Argentina and C. vellerosus to classify them as a separate species. Hence, C. nationiis considered an invalid species and is synonymized with

C. vellerosus based on taxonomic principle of priority. Two subspecies recognized.

Subspecies and Distribution. C.v.vellerosusGray,1865—Bolivia,NEChile,Paraguay,andhighlandsofNWArgentina;itprobablyalsooccursinSEPeru. C. v. pannosus Thomas, 1902 — lower areas of NC Argentina S to Mendoza, La Pampa, and SW Buenos Aires provinces; a disjunct population also occurs in E Buenos Aires Province, which is separated from the main distribution area by ¢.500 km.

Descriptive notes. Head—body 200-300 mm, tail 80-110 mm, ear 29-32 mm, hindfoot 42-52 mm; weight 0.6-1.2 kg. The Screaming Hairy Armadillo is the smallest euphractine. Carapace is variegated brown and pale tan, covered with tan and comparatively dense hair and 6-8 movable transverse bands. Apices of marginal scutes of carapace are rounded. There are 1-2 small openings for pelvic glands on mid-dorsal scutes of pelvic shield. Ears are proportionally long. Legs are short and robust, with flattened claws on all toes. There are four claws on forefeet, second of which is the longest. Chromosomal complement is 2n = 62, FN = 88.

Habitat. Primarily xeric areas at high and low latitudes but never areas with poorly drained soils, and common in rangelands, pastures, and agricultural areas, from sea level to elevations of ¢.4600 m.

Food and Feeding. The Screaming Hairy Armadillo is a carnivore—omnivore, eating primarily arthropods (mainly beetle adults and larvae), plant material, small vertebrates (including anurans, lizards, and different species of rodents), and other invertebrates. It obtainsits food mostly by digging with its strong, long-clawed forefeet. Diets change seasonally in parts of its distribution, with an increase in insect consumption in summer (drier months) and higher proportion of plant material in winter. Kidneys of the Screaming Hairy Armadillo can produce highly concentrated urine as an adaptation to living in a xeric environment. A laboratory experiment about foraging behavior of captive Screaming Hairy Armadillos revealed a systematic search strategy, with a tendency toward a spiral route, which minimized revisits of an area. This strategy was also observed in wild individuals.

Breeding. Male and female Screaming Hairy Armadillos become sexually mature at c.11 months of age. Mating period lasts from end of winter to beginning of spring. Gestation is ¢.60 days, and litters have 1-2 young. A single litter per year is born inside a burrow, in which the female sometimes builds a nest with plant material. Birth weight is 40-60 g. Eyes do not open until ¢.3 weeks of age. Offspring remain inside the burrow during most of the lactation period and start foraging outside the burrow in summer. Average life expectancy has been estimated at c.3 years, and maximum longevity is expected to be 6-10 years.

Activity patterns. The Screaming Hairy Armadillo is nocturnal in summer and diurnal in winter. It can be observed basking in sun around noon in winter, but it remains inside its burrow at nightto avoid low ambient temperatures. In summer, it is active between midafternoon and dawn. Its activity seems to be diurnal throughout the year at high elevations. Individuals are active at different hours of the day, for no more than three hours at a time. The Screaming Hairy Armadillo typically digs burrows in areas with sandy and calcareous soils. In areas with loose soil, burrows are more commonly found near or under vegetation. Burrows can be several meters long and up to 2 m deep. Burrow depth varies seasonally to provide protection from temperature fluctuations; burrows are deeper when daily amplitudes in ambient temperature are higher. Burrows can have several entrancesfor safety and air circulation. Burrow entrances are dome-shaped and c.10 cm wide and 10 cm high. A Screaming Hairy Armadillo might use several burrows in its home range, butit does not necessarily return to the same burrow repeatedly.

Movements, Home range and Social organization. The Screaming Hairy Armadillo is solitary, except for juvenile littermates and during mating season. Home ranges are 0-23-5-3 ha, with males generally having larger home ranges than females. Home ranges overlap within and between sexes. According to a survival analysis performed with data from the disjunct population in eastern Buenos Aires Province (Argentina), the period of lowest survival probability is associated with seasons with low food availability. When frightened, the Screaming Hairy Armadillo can emit a loud scream similar to a human baby crying—origin of its common name. This protest call consists of several long and short notes that are emitted continuously. It seems to be stress-induced and helps to escape from predators by startling them.

Status and Conservation. CITES Appendix II (C. nationi). Classified as Least Concern on The IUCN Red List. Nevertheless, there are two subpopulations that need major attention: one in eastern Buenos Aires Province (Argentina), which is disjunct and subjected to habitat modification by mining and agriculture in its restricted distribution, and the other in Oruro Department (Bolivia), which is intensely harvested and used to manufacture “charangos” (traditional music instruments), “matracas” or “maracas” (rattles), and handicrafts such as amulets and souvenirs.

Bibliography. Abba & Vizcaino (2011), Abba, Benitez & Doyle (2017), Abba, Vizcaino & Cassini (2007), Abba, Zufiaurre et al. (2015), Amaya etal. (2017), Carlini et al. (2016), Cassini (1993), Cuéllar (2008), Gibb etal. (2016), Greegor (1975, 1985), Krmpotic et al. (2012), Pagnutti et al. (2014), Soibelzon et al. (2007), Svartman (2012), Wetzel (1985b).

Figures

1. Six-banded Armadillo (Euphractus sexcinctus), 2. Screaming Hairy Armadillo (Chaetophractus vellerosus), 3. Large Hairy Armadillo (Chaetophractus villosus), 4. Pichi (Zaedyus pichuy), 5. Pink Fairy Armadillo (Chlamyphorus truncatus), 6. Greater Fairy Armadillo (Calyptophractus retusus), 7. Giant Armadillo (Priodontes maximus), 8. Northern Naked-tailed Armadillo (Cabassous centralis), 9. Southern Naked-tailed Armadillo (Cabassous unicinctus), 10. Greater Naked-tailed Armadillo (Cabassous tatouay), 11. Chacoan Naked-tailed Armadillo (Cabassous chacoensis), 12. Brazilian Three-banded Armadillo (Tolypeutes tricinctus), 13. Southern Three-banded Armadillo (Tolypeutes matacus)

Subspecies and Distribution. C.v.vellerosusGray,1865—Bolivia,NEChile,Paraguay,andhighlandsofNWArgentina;itprobablyalsooccursinSEPeru. C. v. pannosus Thomas, 1902 — lower areas of NC Argentina S to Mendoza, La Pampa, and SW Buenos Aires provinces; a disjunct population also occurs in E Buenos Aires Province, which is separated from the main distribution area by ¢.500 km.