Southern bare-tailed armadillo

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Southern bare-tailed armadillo
Preparation of a southern bare-tailed armadillo in the Koenig Museum.

Preparation of a southern bare-tailed armadillo in the Koenig Museum .

Systematics
Order : Armored siderails (Cingulata)
without rank: Armadillos (Dasypoda)
Family : Chlamyphoridae
Subfamily : Tolypeutinae
Genre : Naked- tailed armadillos ( Cabassous )
Type : Southern bare-tailed armadillo
Scientific name
Cabassous unicinctus
( Linnaeus , 1758)

The Southern naked-tailed armadillo , partly only naked-tailed armadillo ( Cabassous unicinctus ), is a member of the genus of cabassous . Its distribution area includes northern and central South America east of the Andes . Two subspecies are known, one of which occurs north and the other south of the Amazon . The armadillo species lives largely underground in caves they have dug themselves. As a result, it is observed relatively seldom, so its way of life is largely unknown. According to the IUCN, their existence is not endangered.

features

Habitus

The southern bare - tailed armadillo has a head-trunk length of 33 to 43 cm (on average 38.2 cm), the clearly slender tail is about 12.5 cm long. The weight varies between 1.6 and 4.8 kg. In South America it occupies a middle position between the small bare-tailed armadillo ( C. chacoensis ) and the large bare-tailed armadillo ( C. tatouay ). Overall, females are larger than males. The head of the armadillo is short and wide, the eyes are very small. The funnel-shaped ears stand wide apart and are rather long at around 3.7 cm. The distinctive forehead shield has a triangular shape and consists of around 54 bone plates. The soft armor on the back, typical of bare-tailed armadillos, covers the entire body up to the base of the legs and is 38 cm long measured over the curvatures. It is divided into a shoulder and a pelvic shield, which consist of transversely running bands of bone platelets with a side length of 6 to 7 mm. The shoulder shield 18 to 28 and the pelvic shield 23 to 8 have these bone platelets per band (counting from front to back). Between the somewhat firmer parts of the shield of the shoulder and pelvic girdle there are twelve moveable ligaments made up of 27 to 28 plates. In addition to the back shield, there are additional bone platelets on the neck and very sparsely formed on the tail. Overall, the southern bare-tailed armadillo is gray-brown to blackish in color, but due to frequent sand cover it appears predominantly yellowish. The back armor has no hair covering, longer hair occurs predominantly on the sides below the armor. The largely hairless belly is grayish in color, the tail is also, but has a paler tip. The very short limbs each end in five rays with sickle-like claws. The middle (third) claw on the forefoot is clearly elongated. Characteristic is the gait in which the southern bare-tailed armadillo touches the hind feet with the entire sole, but the front feet only with the claws. The rear foot length is 7.3 cm.

Skeletal features

The skull becomes 7.8 cm long, on the cheekbones up to 4.4 cm wide and measures 3.4 cm in height. It has a triangular shape when viewed from the side. The rostrum is shorter than the large one, wider and clearly more triangular in shape than the small bare-tailed armadillo. The lower jaw has a narrow shape and is up to 5.9 cm long. The teeth differ from the general dental formula with their teeth, which are atypical for mammals . The southern bare-tailed armadillo has 9 molar-like teeth per jaw half in the upper jaw and 8 molar-like teeth in the lower jaw , so a total of 34. These are partly longer than wide, partly square-shaped and between 2.5 and 3.1 mm long. The entire row of teeth is 2.7 cm long on the upper jaw and 2.4 cm long on the lower jaw. The spine consists of 7 cervical, 12 to 13 thoracic, 3 to 4 lumbar, 9 to 11 lumbar and 15 to 20 caudal vertebrae, making it a total of 46 to 55 vertebrae. The ulna , which is around 5.8 cm long, is striking . The upper end of the joint ( olecranon ) is 2.8 cm long, which is typical for the strong foreleg structure in mammals with a burrowing way of life.

Sensory performances and vocalizations

A pig-like squeaking is known to be the only sound uttered by male animals ; female animals seem to make no or only seldom sounds.

distribution and habitat

Distribution area

The southern bare-tailed armadillo is distributed over large parts of South America east of the Andes . It occurs in Brazil on both sides of the Amazon . In the north it extends from the lowlands of Peru and Ecuador via Colombia and Venezuela to Suriname . In the south it is found with a smaller population in northern Bolivia , where it was first sighted in 2006, and in Paraguay , where it was only detected in early 2011. The habitats are often less than 600 m above sea level, in Colombia and Ecuador animals could be observed on the eastern slopes of the Andes at 1200 and 1500 m altitude, respectively. The entire distribution area is given with a size of 9.66 million square kilometers. The population density varies greatly between the individual regions. In Venezuela's mountainous landscapes, 0.75 to 1.2 individuals per square kilometer are assumed, in the Cerrado region it is 27 individuals on a comparable area, while in the Pantanal there are 2.2 animals per square kilometer.

Because of its wide distribution, the habitat includes both the tropical rainforests of the Amazon region and the Atlantic coastal forests ( Mata Atlântica ). The southern bare-tailed armadillo is also found in the open Cerrado savannas and dry caatinga forests of Brazil, as well as in the humid Pantanal regions. In the southern distribution area, the Chiquitano dry forests are also inhabited, a transition region from the open landscapes of the Cerrado to the Gran Chaco thorn bush savannah. In general, however, the armadillo species prefers areas with more complex vegetation , such as gallery forests. The southern bare-tailed armadillo is very rarely seen in cultivated areas. In the south it occurs partly together with the great naked- tailed armadillo ( Cabassous tatouay ), with which it is sometimes confused. In the north, it lives sympathetically with the Central American naked- tailed armadillo ( Cabassous centralis ). In areas with a common occurrence with the six-banded armadillo ( Euphractus sexcinctus ) there is hardly any overlap in the ecological niches used .

Way of life

Territorial behavior

Little information is available about the way of life of the southern bare-tailed armadillo. It is solitary and possibly nocturnal, but most observations in the Cerrado region have so far been recorded during the day. The individual animals maintain territories . According to observations of 10 animals in the Pantanal over a period of 24 months, the average territory size for males is 2.06 km², for females 0.59 km². The territories of the males overlap with several of the females, but there is hardly any overlap within the sexes. The southern bare-tailed armadillo lives largely in underground, self-dug burrows. According to investigations in the Canastra National Park in the Brazilian state of Minas Gerais, these are 17 cm wide, 15 cm high and up to 45 cm deep and reach into the ground at an angle of 35 °. Each building has a single entrance on the leeward side. Some of the structures are built on flat slopes. Analyzes of buildings in the Brazilian state of Sao Paulo showed a circumference at the entrance of 33 to 40 cm and a depth of 18 to 60 cm. As a rule, the southern bare-tailed armadillo burrows in circular turns, which is why the entrances are mostly rounded. Often an animal uses the burrow for a maximum of 24 hours, and a return to the same shelter is very rare. In almost half of the cases observed, the burrows were in abandoned termite mounds, and almost as many in those that were still inhabited. When foraging for food, the southern bare-tailed armadillo creates long galleries. On average, it spends around 99% of the day underground. It only comes to the surface of the earth shortly after the highest point of the sun and therefore at the hottest time of the day. The southern bare-tailed armadillo only stays there for about 6.5 minutes. During this period, an animal can travel up to 781 m, an average of 83 m. The southern bare-tailed armadillo also uses its good digging skills when threatened. To burrow completely, an animal needs about 45 seconds.

nutrition

The main food consists of ants and termites , which the southern bare-tailed armadillo gains by breaking open burrows and nests with its front claws. The long tongue is used to take in food. The preferred ingested insects include termites of the Cornitermes genus , which in the Mato Grosso region covers up to 95% of the total food requirement. Workers and soldiers in particular are consumed here. The remaining 5% are accounted for by other insects. Further studies of stomach contents from the Cerrado region also showed a preference for Cornitermes individuals as the most common source of food, with over 56% ; those from Rhynchotermes were also found to be subordinate . A larger proportion of the termite remains could not be determined, however, only a few mites appeared as food remains. The southern bare-tailed armadillo is particularly active in times of food shortages and goes on longer hikes.

Reproduction

Little is known about reproduction, but it does not seem to be seasonally dependent, as animals observed in the Cerrado region showed sexual activity during both the dry and rainy seasons . The gestation period is assumed to be four months. Maternal care for the offspring lasts just as long. Usually a young animal is born. The lifespan in the wild is unknown, two animals kept in captivity lived over four years.

Parasites

The external parasites include fleas of the genus Tunga , which penetrate the neck and front extremities. Ticks have also been detected with Amblyomma . As internal parasites are nematodes such as Trichohelix and Hadrostrongylus . The southern bare-tailed armadillo is still a carrier of the protozoon Trypanosoma .

Systematics

Internal systematics of the armadillos according to Gibb et al. 2015
  Dasypoda  
  Dasypodidae  

 Dasypus


  Chlamyphoridae  
  Euphractinae  

 Euphractus


   

 Chaetophractus


   

 Zaedyus




   
  Chlamyphorinae  

 Chlamyphorus


   

 Calyptophractus



  Tolypeutinae  

 Priodontes


   

 Tolypeutes


  Cabassous  

 Cabassous tatouay


   

 Cabassous chacoensis


   

 Cabassous centralis


   

 Cabassous unicinctus










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The southern bare-tailed armadillo is a species from the genus of the bare- tailed armadillos ( Cabassous ), which has a further three members. The bare-tailed armadillos belong to the group of armadillos (Dasypoda) and within this to the family of Chlamyphoridae and to the subfamily of Tolypeutinae . The most closely related forms are the giant armadillos ( Priodontes ) and the spherical armadillos ( Tolypeutes ). The group of Tolypeutinae is opposite to the subfamily of Chlamyphorinae with the two girdle species as sister taxons. In a more distant relationship are Euphractinae with the bristle armadillos ( Chaetophractus ) and the six-banded armadillo ( Euphractus ) queued. According to molecular genetic studies, the Chlamyphorinae and the Tolypeutinae separated in the Oligocene 33 million years ago, and the Tolypeutinae have been more fragmented since the early Miocene . The southern bare-tailed armadillo may have first appeared in the Upper Pleistocene , but there is hardly any fossil evidence.

There are two subspecies of the southern bare-tailed armadillo:

  • C. u. squamicaudis Lund , 1845; more southern and smaller subspecies (south of the Amazon)
  • C. u. unicinctus Linnaeus , 1758; more northern and larger subspecies (north of the Amazon)

The distribution areas of the two subspecies are geographically largely separated from each other by the Amazon, only in the western part of the Amazon basin on the upper reaches of the Amazon (Solimões) do they overlap. It is sometimes discussed whether the two forms are not separate species, whereupon the tail, which is much more densely covered with bone platelets, in C. u. squamicaudis or deviating head, trunk and tail proportions. However, Ralph Martin Wetzel , who last subjected the genus Cabassous to a major revision in 1980 , temporarily left the status as a subspecies.

The southern bare-tailed armadillo was first named in 1758 by Linnaeus as Dasypus unicinctus , with which he referred the armadillo to the long-nosed armadillos . He also gave Africa as his home country. Only Oldfield Thomas gave the type locality with Suriname in 1911 . Theodore Sherman Palmer first used the common name Cabassous unicinctus in 1899 . Sometimes the armadillo was also led under the generic name Ziphila , introduced by John Edward Gray in 1873 . The species name unicinctus is of Latin origin and means uncia ("twelve") and cingulum ("belt"; cinct "belted") and thus refers to the twelve freely movable ligaments.

Threat and protection

According to the IUCN, the southern bare-tailed armadillo is not subject to any major threats and is also listed as "not at risk" ( least concern ) due to its wide distribution . Locals sometimes hunted it, but this is more opportunistic than targeted. Furthermore, the conversion of natural areas into arable land can have a negative impact on the population. The more southerly stretching of the habitat, which has only been discovered since 2011, but also the data gaps in individual regions resulting from the hidden way of life, such as in the Pantanal, suggest that this armadillo species is more widespread. The southern bare-tailed armadillo occurs in several protected areas, such as in the Floresta Nacional Saracá-Taquera in Brazil or in the Reserva Natural Laguna Blanca in Paraguay.

literature

  • Virginia Hayssen: Cabassous unicinctus (Cingulata: Dasypodidae). In: Mammalian Species. 46 (907), 2014, pp. 16-23.
  • Mariella Superina and Agustín Manuel Abba: Chlamyphoridae (Chlamyphorid armadillos). In: Don E. Wilson and Russell A. Mittermeier (eds.): Handbook of the Mammals of the World. Volume 8: Insectivores, Sloths and Colugos. Lynx Edicions, Barcelona 2018, pp. 48-71 (p. 70) ISBN 978-84-16728-08-4

Individual evidence

  1. ↑ a b c d e f g h i Paul Smith: Southern naked-tailed armadillo Cabasssous unicinctus (Linnaeus, 1758). In: Mammals of Paraguay. 40, 2011, pp. 1-10.
  2. ↑ a b c d e f g h Virginia Hayssen: Cabassous unicinctus (Cingulata: Dasypodidae). In: Mammalian Species. 46 (907), 2014, pp. 16-23.
  3. ↑ a b c d e f Mariella Superina and Agustín Manuel Abba: Chlamyphoridae (Chlamyphorid armadillos). In: Don E. Wilson and Russell A. Mittermeier (eds.): Handbook of the Mammals of the World. Volume 8: Insectivores, Sloths and Colugos. Lynx Edicions, Barcelona 2018, pp. 48-71 (p. 70) ISBN 978-84-16728-08-4
  4. ^ SF Vizcaíno, N. Milne: Structure and function in armadillo limbs (Mammalia: Xenarthra: Dasypodidae). In: Journal of Zoology. 257, 2002, pp. 257, 117-127.
  5. ^ A b Leonardo Maffei: Extension of the Distribution of Cabassous unicinctus in Santa Cruz, Bolivia. In: Edentata. 7, 2006, pp. 53-54.
  6. ^ A b Paul Smith, Robert D. Owen, Karina Atkinson, Hugo Del Castillo, Emma Northcote-Smith: First Records of the Southern Naked-Tailed Armadillo Cabassous unicinctus (Cingulata: Dasypodidae) in Paraguay. In: Edentata. 12, 2011, pp. 53-57.
  7. ↑ Héctor E. Ramírez-Chaves, Juan Pablo López Ordóñez, Nestor A. Peralta, Carlos A. Aya-Cuero: A noteworthy elevational record of the Southern naked-tailed armadillo Cabassous unicinctus in Colombia, with comments on the species distribution in the country . In: Edentata. 18, 2017, pp. 68-72
  8. ^ A b I. M. Medri, W. Moraes Tomas: Cabassous unicinctus. In: Edentata. 11 (2), 2010, p. 144.
  9. ↑ a b c d Vinícius Bonato, Eduardo G. Martins, Glauco Machado, Cibele Q. da-Silva, Sérgio F. dos Reis: Ecology of the Armadillos Cabassous unicinctus and Euphractus sexcinctus (Cingulata: Dasypodidae) in a Brazilian Cerrado. In: Journal of Mammalogy. 89 (1), 2008, pp. 168-174.
  10. ↑ a b c d e f Arnaud Leonard Jean Desbiez, Gabriel Favero Massocato, Danilo Kluyber, Renata Carolina Fernandes Santos: Unraveling the cryptic life of the southern naked-tailed armadillo, Cabassous unicinctus squamicaudis (Lund, 1845), in a Neotropical wetland: Home range, activity pattern, burrow use and reproductive behavior. In: Mammalian Biology. 91, 2018, pp. 95-103
  11. ^ A b Alfred L. Gardner: Mammals of South America, Volume 1: Marsupials, Xenarthrans, Shrews, and Bats. University of Chicago Press, 2008, ISBN 978-0-226-28240-4 , pp. 148-153.
  12. ↑ a b Mariella Superina, Augusín M. Abba: Cabassous unicinctus. In: IUCN: IUCN Red List of Threatened Species. Version 2012.2. ( [1] ) last accessed on January 12, 2013
  13. ↑ a b Tracy S. Carter, Christiane D. Encarnação: Characteristics and Use of Burrows by Four species of armadillos in Brazil. In: Journal of Mammalogy. 64, 1983, pp. 103-108.
  14. ^ Roberto Guilherme Trovati: Differentiation and characterization of burrows of two species of armadillos in the Brazilian Cerrado. In: Chilena de Historia Natural. 88, 2015, p. 19. doi: 10.1186 / s40693-015-0049-z
  15. ↑ Kent H. Redford: The Edentates of the Cerrado. In: Edentata. 1, 1994, pp. 4-10.
  16. ↑ Maria Clara Arteaga, Eduardo Martins Venticinque: Influence of topography on the location and density of armadillo burrows (Dasypodidae: Xenarthra) in the central Amazon, Brazil. In: Mammalian Biology. 73, 2008, pp. 262-266.
  17. ↑ Teresa Cristina da Silveira Anacleto: Food Habits of Four Armadillo Species in the Cerrado Area, Mato Grosso, Brazil. In: Zoological Studies. 46 (4), 2007, pp. 529-537.
  18. ↑ E. Hinz: On the distribution and spread of the genus Tunga (Siphonaptera: Pulicidae) with special consideration of T. penetrans. In: Communications from the Austrian Society for Tropical Medicine and Parasitology. 18, 1996, pp. 173-182.
  19. ↑ EGL Hoppe, RC Araújo de Lima, JH Tebaldi, ACR Athayde, AA Nascimento: Helminthological records of six-banded Armadillos Euphractus sexcinctus (Linnaeus, 1758) from the Brazilian semi-arid region, Patos county, Paraíba state, including new morphological data on Trichohelix tuberculata (Parona and Stossich, 1901) Ortlepp, 1922 and proposal of Hadrostrongylus ransomi nov. comb. In: Brazilian Journal of Biology. 69 (2), 2009, pp. 423-428.
  20. ↑ a b Gillian C. Gibb, Fabien L. Condamine, Melanie Kuch, Jacob Enk, Nadia Moraes-Barros, Mariella Superina, Hendrik N. Poinar, Frédéric Delsuc: Shotgun Mitogenomics Provides a Reference Framework Phylogenetic and Time Scale for Living Xenarthrans. In: Molecular Biology and Evolution. 33 (3), 2015, pp. 621–642.
  21. ↑ Maren Möller-Krull, Frédéric Delsuc, Gennady Churakov, Claudia Marker, Mariella Superina, Jürgen Brosius, Emmanuel JP Douzery, Jürgen Schmitz: Retroposed Elements and Their Flanking Regions Resolve the Evolutionary History of Xenarthran Mammals (Armadillos, Anteaters and Sloths). In: Molecular Biology and Evolution. 24, 2007, pp. 2573-2582.
  22. ↑ Frédéric Delsuc, Mariella Superina, Marie-Ka Tilak, Emmanuel JP Douzery, Alexandre Hassanin: Molecular phylogenetics unveils the ancient evolutionary origins of the enigmatic fairy armadillos. In: Molecular Phylogenetics and Evolution. 62, 2012, 673-680
  23. ↑ Oldfield Thomas: The mammals of the tenth edition of Linnaeus; an attempt to fix the types of the genera and the exact bases and localities of the species. In: Proceedings of the Zoological Society of London. 1911, pp. 120-158.
  24. ^ Theodore Sherman Palmer: Notes on Tatoua and other genera of Edentates. In: Proceedings of the Biological Society of Washington. 13, 1899, pp. 71-73 ( [2] )
  25. ^ Paul Smith: Assessing the assessment, the relevance of the 2006 Paraguayan mammal Red List to the reality of Xenarthra conservation in 2012. In: Edentata. 13, 2012, pp. 18-28.
  26. ↑ Leonardo de Carvalho Oliveira, Sylvia Miscow Mendel, Diogo Loretto, José de Sousa e Silva Júnior, Geraldo Wilson Fernandes: Edentates of the Saracá-Taquera National Forest, Pará, Brazil. In: Edentata. 7, 2006, pp. 3-7.

Web links

Commons : Cabassous unicinctus  - collection of images, videos and audio files