Screaming hairy armadillo
Chaetophractus vellerosus

Chaetophractus vellerosus is generally known from the Chaco region of Bolivia, Paraguay and Argentina. A disjunct population occurs in eastern Buenos Aires Province, Argentina. Recent studies have confirmed that C. nationi is an invalid species and a synonym of C. vellerosus. Hence, the distribution of C. vellerosus now also includes the high altitudes of Chile (Arica y Parinacota, Antofagasta, Tarapacá), Bolivia and Argentina. Its presence in Peru is uncertain. The species occurs at altitudes from sea level to 4,600 m asl.


The Screaming Hairy Armadillo is primarily found in xeric environments, in lowland and upland areas as well as high altitude grasslands with loose sandy soils, it also has been recorded from rangeland pasture and agricultural areas. In Buenos Aires province this armadillo lives on sandy-calcareous soils and prefers grasslands with low vegetation and high vegetation cover (Abba et al. 2011). 


This omnivorous animal constructs burrows and therefore is absent from rocky areas where burrows cannot be excavated (Greegor 1985; Abba et al. 2007, 2011; Abba and Cassini 2008; Pérez Zubieta 2008, 2011). Its diet is mainly composed of beetles, lepidopteran larvae, plant matter and small vertebrates (Greegor 1980, Soibelzon et al. 2007, Abba et al. 2011).
In Bolivia, Screaming Hairy Armadillos use crop areas while searching for food, while sand dunes are vital for their survival because they use them for burrow construction and foraging (Pérez Zubieta 2011).
During the cold season, Screaming Hairy Armadillos are mainly active at noon and the early afternoon, while in warm seasons their activity period shifts to the afternoon and night (Greegor 1980, Abba et al. 2011). However, their activity seems to be diurnal throughout the year at high altitudes (Zúñiga and Araya 2014).
The estimated home range size is 3.4 ha in Catamarca, Argentina (Greegor 1980) and 1 to 5.3 ha in Buenos Aires province, Argentina (Glaz and Carlini 1999). Pagnutti et al. (2014) described seasonal differences in home range size in a closed population in Buenos Aires province, Argentina: in fall-winter, home range size was 0.23 ha and 0.27 ha in males and females, respectively, while it was 0.75 and 0.13 ha, respectively, during spring-summer. In this population, the spatial distribution of C. vellerosus was aggregated and possibly influenced by land use (Pagnutti et al. 2014). 
Densities of 0.58 animals/km2 have been observed in Kaa-Iya National Park, Bolivia (Cuéllar 2008). Peredo (1999) estimated a total population of 13,000 individuals in an area of 340 km2 in Bolivia.
C. vellerosus is a seasonal breeder. Its reproductive season lasts from September to January in Buenos Aires province (Abba et al. 2011) and November to January in Bolivia (Cuéllar 2008). One to two offspring per litter are born inside the burrow after a gestation period of 60 days. Offspring remain inside the burrow during the entire lactation and start emerging in January-February.



Chaetophractus vellerosus is heavily hunted for its meat and carapace including for charangos, a musical instrument, and matracas or maracas (Cuéllar and Noss 2003, Aguiar and Fonseca 2008, Noss et al. 2008, Romero-Muñoz and Pérez-Zubieta 2008). It is also persecuted as an agricultural pest. In addition, some animals are killed by hunting dogs and by cars on roads. The isolated population on the coast of Buenos Aires Province, Argentina, is negatively affected by mining activities (Abba 2008, Abba et al. 2011).

C. vellerosus also suffers from habitat loss from sand excavation for concrete production (Peredo 1999) and agricultural activities (Ríos and Rocha 2002). Animals living at high altitudes of Bolivia (previously considered to be C. nationi) are negatively affected by the intense use to make handicrafts, especially for the carnival in Oruro. Cáceres (1995) estimated that 2,000 individuals are harvested each year for this purpose. Illegal trade from Chile to Bolivia as well as within Bolivia has been reported and seems to be related to the reduction of the subpopulation near Oruro and the resulting difficulties to obtain animals for handicraft production. Although the extent of this illegal trade has not been quantified, it is suspected to negatively affect the local population.


Chaetophractus vellerosus is listed as Least Concern as, although susceptible to hunting in parts of its range, it is widespread and rates of offtake are not believed to be at a level that would warrant listing in a threatened category. However, there are two subpopulations that need major attention: one in the east of Buenos Aires Province (Argentina), which is disjunct and subjected to habitat modification in its restricted range; and the other in Oruro department (Bolivia), which apparently is not disjunct and is intensely harvested and used to manufacture charangos (traditional music instruments), matracas or maracas (rattles), and handicrafts such as amulets and souvenirs.

Roughly 60% of the Bolivian range corresponds to the range of the high-altitude population previously known as C. nationi. Peredo (1999) reported more than 15 years ago that increasing difficulties in finding “quirquinchos” in the wild had led artisans from the region of Oruro and La Paz to start using C. vellerosus individuals (Tarifa and Romero-Muñoz 2009). Because Municipal Bylaw 31/99 in Oruro did not succeed in reducing the use of Chaetophractus carapaces in traditional dances (Pérez-Zubieta et al. 2009), it is probable that the impact of hunting is increasingly affecting both the high-altitude (formerly C. nationi) and southern (C. vellerosus) subpopulations of Bolivia. In addition, illegal trade of specimens from Chile to Bolivia has been reported. This potential threat to the Chilean subpopulation should be closely monitored.
The genetic data published by Abba et al. (2015) indicate that Chaetophractus specimens from high-altitudes of Bolivia share a unique mitochondrial haplotype, which is also found in a C. vellerosus specimen from Argentina. This absence of genetic diversity observed in the 10 individuals sampled within the Oruro region suggests a local reduction of effective population size (Abba et al. 2015). There is therefore no doubt that the synonymized C. vellerosus would have to be listed in a threatened category—either Vulnerable or Endangered—within Bolivia and that conservation measures should be implemented as soon as possible to save the species from regional extinction (Abba et al. 2015).
Chaetophractus vellerosus is present in a number of protected areas, including the Kaa-Iya National Park in Santa Cruz, Bolivia. The high-altitude animals are present in the Sajama National Park, Bolivia, and in Lauca National Park, Chile. The high-altitude armadillos, formerly known as C. nationi, were previously listed as Vulnerable (VU A2acd; IUCN 2014). This species, which is now a synonym of C. vellerosus, was considered Endangered (EN) in Bolivia (Pérez-Zubieta et al. 2009), Chile (DS 5/1998 MINAGRI, Servicio Agrícola Ganadero 1998), and in Peru (Supreme Decree 004-2014 MINAGRI) although its presence in the latter country is uncertain, and Data Deficient (DD) in Argentina (Superina et al. 2012). In addition, C. nationi is included in CITES Appendix II (CITES 2013), which establishes a zero annual exportation quota for this species due to its traditional use (Peredo 1999).

These animals are considered emblematic of the Bolivian highlands, particularly from the Oruro department (Cáceres 2004) where they are closely linked to the cultural heritage.


Additional information and a complete list of references can be found in: IUCN SSC Anteater, Sloth and Armadillo Specialist Group. 2016. Chaetophractus vellerosus. The IUCN Red List of Threatened Species 2016: e.T89604632A89605338. This Red List Account is available here.

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