Southern seven-banded armadillo

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Southern seven-banded armadillo
Southern seven-banded armadillo (Dasypus hybridus)

Southern seven-banded armadillo ( Dasypus hybridus )

Systematics
Order : Armored siderails (Cingulata)
without rank: Armadillos (Dasypoda)
Family : Dasypodidae
Subfamily : Dasypodinae
Genre : Long-nosed armadillos ( Dasypus )
Type : Southern seven-banded armadillo
Scientific name
Dasypus hybridus
( Desmarest , 1804)

The southern seven-banded armadillo ( Dasypus hybridus ) is a small species of long-nosed armadillos and is mainly found in the middle east of South America . It lives in open grasslands and reacts strongly to human landscape changes. The main food consists of insects and , to a lesser extent, plants. The stock is currently classified as potentially endangered by the IUCN .

features

Habitus

Southern seven-banded armadillo, neotype

The southern seven-banded armadillo has an average head-trunk length of 29.7 cm, plus a 16.9 cm long and at the base quite broad tail, which is the shortest of all long-nosed armadillos compared to body length and only 67 to Reached 70% of the length of the rest of the body. The total length varies from 39.7 to 48.9 cm, the weight is 1 to 2 kg. Overall, the animal has a broad and low body with a narrow, triangular head that is characteristically long drawn out at the muzzle. This is up to 7.5 cm long and has up to 2.8 cm long, bag-like ears with rounded ends, which are characteristically wide apart. The body armor has a firmer shoulder and pelvic part, in between there are 6 or 7 ligaments connected by hairless strips of skin. The entire back shield is made up of individual small bone plates, which are hexagonal on the fixed armor, but rectangular on the moving part. The hexagonal osteoderms have a diameter of around 5 mm and are covered with a circular pattern, which is sometimes off-center, and is surrounded by eight small patterns. The bone platelets of the movable ligaments, on the other hand, are around 20 mm long and 5 mm wide. Their surface is characterized by a triangular pattern, with the tip of the central triangle pointing forward. The number of bone platelets on the fourth movable ligament is between 50 and 62 each and an average of 54, other authors give 46 to 55 and 53 respectively. There are additional bone platelets on the top of the head, but they are irregularly shaped and have no pattern. The body color tends from brownish-gray to brownish-yellow, but is usually darker in the front area. Some individuals also have a darker median on their back. In addition, the carapace is covered by only a slight fluff of hair. The belly has no hair and is pink in color. The limbs are short and end in four rays on the front legs and five rays on the hind legs, which have powerful claws. The two middle front feet are particularly strong. The rear foot length is 7.3 cm. Females have four mammary glands .

Skeletal features

The teeth of the southern seven-banded armadillo have teeth that differ from those of other mammals , which are shaped like pegs and are so molar-like , but have no enamel . In each jaw arch there are 6 teeth in the upper jaw and 8 in the lower jaw, so a total of 28. Furthermore, the skeleton on the front legs has a ulna shape that is characteristic of burrowing mammals . Here the upper joint ( olecranon ) is significantly enlarged and up to 2 cm long, with a total length of the bone of 4.9 cm.

Sensory performances and vocalizations

The only known vocalizations are puffing noises while searching for food.

distribution and habitat

Distribution area

The distribution area of ​​the southern seven-banded armadillo is the southernmost of all long-nosed armadillos. It occurs from northeast Argentina via Uruguay to southern Brazil . There are individual reports of sightings from southern Paraguay , the last specimen was found dead in December 2006. The exact northern limit of distribution is unknown, as it is often confused with the similar seven-banded armadillo ( Dasypus septemcinctus ). The total size of the distribution area is given as 1.42 million square kilometers, the size of the actually inhabited areas and the density of the population is unknown. The armadillo mainly inhabits uncultivated open grasslands and pampas and reacts sensitively to human influences in the form of arable farming or grazing. The habitat is also limited by the expansion of the Atlantic coastal forests ( Mata Atlântica ), but open wooded areas are also partially populated. Overall, the animal has been detected from the coastal plain to land heights around 2300 m above sea level. The southern seven-banded armadillo prefers to inhabit moist soils. In some regions it lives sympatric with the brown bristle ( Chaetophractus vellerosus ) and the small bristle armadillo ( Chaetophractus villosus ), but there is also an overlap with the range of the nine-banded armadillo ( Dasypus novemcinctus ).

Way of life

Territorial behavior

The southern seven-banded armadillo is active both day and night, but mostly at night in summer to avoid the heat of the day. In addition, it is less likely to be found outside of the burrow in winter, which may be related to a reduced food supply. The self-dug structures are mostly created in grasslands that are not influenced by humans and which also have sandy soils; There are hardly any burrows in forest areas. They are typically 1 to 2 m long, but can also reach up to 5 m, about 15 cm wide and up to 45 cm high. Mostly they are simple long, sometimes angled tubes that extend flat into the ground, only rarely do they end in small chambers of 25 to 35 cm in size. The entrances usually have a diameter of 25 cm and are often against the wind direction. In addition, they can sometimes be blocked with dry grass. The entrance area is mostly very steep in the underground. Some of the buildings also have two entrances that merge into a tunnel after a short distance. In addition to these burrows, there are also smaller caves in the ground, which probably serve to protect against predators and are quickly created when danger approaches. The longer burrows also serve as winter quarters; in these, the inside temperature is higher than the outside temperature. The body temperature fluctuates relatively strongly between 33.1 and 38.4 ° C, it depends on the ambient temperature and the activity of the animals. It is possible that the southern seven-banded armadillo falls into a torpor or hibernation under unfavorable external conditions , similar to what has been demonstrated for the dwarf armadillo ( Zaedyus pichiy ).

nutrition

The main diet consists of ants and termites , which make up about 50% of the total ingested amount. The armadillo also eats grasshoppers , butterflies , beetles and cockroaches . The southern seven-banded armadillo also rarely eats small vertebrates, but it is unclear here whether they are actively preying on them or whether they are eating on carcasses . Leaves and seeds also belong in the food repertoire. While foraging for food, an animal runs quickly back and forth, digs small holes with the sharp claws of its forefeet and gives off a constant puffing.

Reproduction

The reproduction under free-living Southern Seven-banded armadillos has been observed rarely in animals in captivity the breeding season was mainly in March, the birth with 7-12 pups in October and November , representing a gestation period equivalent of about seven months. Due to polyembryony , the offspring are genetically identical. The birth takes place in the burrow, which is laid out like a nest with plants. Newborns weigh an average of 47.5 g, have open eyes and a soft shell. They are suckled for about two months.

Predator and enemy behavior

No direct predators are known, but the number of animals is lower in areas where wild dogs are more common. In the event of danger, the southern seven-banded armadillo escapes quickly, but not in a straight line, to a nearby burrow.

Parasites

The external parasites include fleas such as Tunga and Rhophalopsyllus , mites such as Androlaelaps and ticks such as Amblyomma , although the latter does not seem to infest the southern seven-banded armadillo very often. The internal parasites are mostly roundworms , including Aspidodera , Pterygodermatites , Mazzia and Delicata , among others . In addition, the armadillo is the host of the single cell Trypanosoma cruzi , which is the cause of Chagas disease in humans.

Systematics

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

 Dasypus kappleri


   


 Dasypus septemcinctus


   

 Dasypus hybridus



   


 Dasypus mazzai


   

 Dasypus sabanicola



   

 Dasypus novemcinctus


   

 Dasypus pilosus






  Chlamyphoridae  
  Euphractinae  

 Euphractus


   

 Chaetophractus


   

 Zaedyus




   
  Chlamyphorinae  

 Chlamyphorus


   

 Calyptophractus



  Tolypeutinae  

 Priodontes


   

 Tolypeutes


   

 Cabassous







Template: Klade / Maintenance / Style

The southern seven-banded armadillo belongs to the genus of long-nosed armadillos ( Dasypus ), to which six other species are assigned. The long-nosed armadillos , in turn, belong to the group of armadillos (Dasypoda). The Dasypus genus forms its own family , the Dasypodidae , which, according to molecular genetic studies, split off from the line of other armadillos around 45 million years ago in the Middle Eocene . The Dasypodidae also include numerous extinct genera such as Stegotherium , which has been proven from the Miocene and includes several species. The closest related group is the family of the Chlamyphoridae , to which all other modern armadillos are assigned. Within the long-nosed armadillos , the seven-banded armadillo ( Dasypus septemcinctus ) is the closest relative of the southern seven-banded armadillo.

There are no known subspecies of the Southern seven-banded armadillo, but the shape is occasionally viewed as a subspecies of the seven-banded armadillo. The first description was made by Anselme Gaëtan Desmarest in 1804 as Loricatus hybridus without specifying a type locality . The description was based on the report "Le Tatou Mulet" by Félix de Azara , which he had published in 1801 in Essais sur l'Histoire Naturelle des Quadrupèdes de la Province du Paraguay . However, Azara's description of the southern seven-banded armadillo is relatively imprecise, in a later report published in 1823 he mentions tatuejo-mulita and tatuejo oscuro , the former is not exactly assignable, the latter corresponds to the nine-banded armadillo ( Dasypus novemcinctus ). The armadillo was often confused with the northern seven-banded armadillo ( Dasypus septemcinctus ). It was not until 1939 that GWD Hamlett presented diagnostic features that separate the southern seven-banded armadillo from the seven-banded armadillo. These concerned, among other things, the absolute and relative lengths of the tail and ears. In 1995, a new, very similar species, the Yungas armadillo ( Dasypus mazzai ) was re-described, which is native to northeast Argentina . The generic name Dasypus is of Greek origin and is the translation of the Aztec word Azotochtli , which the Spanish conquistador Francisco Hernández de Córdoba made known in Europe as the name for the nine-banded armadillo and which can be roughly translated as "turtle hare". The term refers to the animal's appearance, as does the species name hybridus , which means “mixed”. The Spanish word mulita , which is often used in the region, means "little donkey" and is reminiscent of the donkey-like ears. The Guaraní word tatu mburica , which means “donkey armadillo”, alludes to this.

Threat and protection

The greatest threat is the frequent hunt for the southern seven-banded armadillo, which takes place on the one hand for food reasons, on the other hand for the production of art objects, which can be traced back to pre-Columbian times. The loss of habitat due to the spread of agriculture and human settlements is also of great importance , since the animal is extremely sensitive to changes and as a result it has disappeared in many areas, especially in Argentina. As a result, there has been a significant decline in stocks over the past 30 years. In addition, the armadillo is a common victim of road traffic accidents and wild dogs. The IUCN assesses the population as near threatened ("potentially endangered"), but there are data gaps in some areas and it is recommended to increase the classification to vulnerable ("endangered"). In Uruguay, on the other hand, the armadillo has a high protection priority. The southern seven-banded armadillo is represented in a number of nature reserves, including the Campos del Tuyú , El Palmar and Rio Pilcomayo national parks .

literature

  • Agustín M. Abba and Mariella Superina: Dasypus hybridus (Cingulata: Dasypodidae). Mammalian Species 48 (931), 2016, pp. 10-20 DOI: 10.1093 / mspecies / sew001
  • CM McDonough and WJ Laughry: Dasypodidae (Long-nosed 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. 30–47 (pp. 46–47) ISBN 978-84-16728-08-4

Individual evidence

  1. ^ Edgardo Mondolfi: Descripción de un nuevo armadillo del género Dasypus de Venezuela (Mammalia - Edentata). Memoria de la Sociedad de Ciencias Naturales La Salle 78, 1968, pp. 149-167
  2. ↑ Anderson Feijó and Pedro Cordeiro-Estrel: The correct name of the endemic Dasypus (Cingulata: Dasypodidae) from northwestern Argentina. Zootaxa 3887 (1), 2014, pp. 88-94
  3. ↑ a b c d e f g h i j Paul Smith: Southern long nosed armadillo Dasypus hybridus (Desmarest, 1804). Mammals of Paraguay 15, 2008, pp. 1-10
  4. ↑ a b c d e f Agustín M. Abba and Mariella Superina: Dasypus hybridus (Cingulata: Dasypodidae). Mammalian Species 48 (931), 2016, pp. 10-20
  5. ↑ a b c d C. M. McDonough and WJ Laughry: Dasypodidae (Long-nosed 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. 30–47 (pp. 46–47) ISBN 978-84-16728-08-4
  6. ^ SF Vizcaíno and N. Milne: Structure and function in armadillo limbs (Mammalia: Xenarthra: Dasypodidae). Journal of Zoology 257, 2002, pp. 117-127
  7. ↑ a b Agustín M. Abba and M. Superina: Dasypus hybridus. Edentata 11 (2), 2010, p. 156
  8. ↑ a b c d Agustín M. Abba, Sergio F. Vizcaíno and Marcelo H. Cassini: Effects of land use on the distribution of three species of armadillos in the Arentinaean pampas. Journal of Mammalogy 88 (2), 2007, pp. 502-507
  9. ↑ Enrique M. González, Alvaro Soutollo and Carlos A. Altuna: The Burrow of Dasypus hybridus (Cingulata: Dasypodidae). Acta Theriologica 46, 2001, pp. 53-59
  10. ↑ a b c Agustín M. Abba, Guillermo H. Cassini and Fernando C. Galliari: Nuevos aportes a la historia natural de la mulita pampeana Dasypus hybridus (Mammalia, Dasypodidae). Iheringia, Série Zoologia 101 (4), 2011, pp. 325-335
  11. ^ A b Agustín M. Abba and Marcelo H. Cassini: Ecological differences between two sympatric species of armadillos (Xenarthra, Mammalia) in a temperate region of Argentina. Acta Theriologica 55 (1), 2010, pp. 35-44
  12. ^ A b C. C. Ferrari, PD Carmanchahi, ML Bolkovic and JM Affanni: Breeding in Captivity of the Southern Lesser Long-nosed Armadillo Dasypus hybridus. Zoocriaderos 2, 1997, pp. 1-5
  13. ↑ María C. Ezquiaga, María C. Digiani and Graciela T. Navone: A New Molineid (Nematoda: Trichostrongylina) Parasite of Dasypus hybridus (Xenarthra: Dasypodidae) from Argentina. Journal of Parasitology 98 (6), 2012, pp. 1156-116
  14. ↑ a b Gillian C. Gibb, Fabien L. Condamine, Melanie Kuch, Jacob Enk, Nadia Moraes-Barros, Mariella Superina, Hendrik N. Poinar and Frédéric Delsuc: Shotgun Mitogenomics Provides a Reference Phylogenetic Framework and Timescale for Living Xenarthrans. Molecular Biology and Evolution 33 (3), 2015, pp. 621-642
  15. ↑ Timothy J. Gaudin and John R. Wible: The phylogeny of living and extinct armadillos (Mammalia, Xenarthra, Cingulata): a craniodental analysis. In: Matthew T. Carrano, Timothy J. Gaudin, Richard W. Blob, and John R. Wible (Eds.): Amniote Paleobiology: Phylogenetic and Functional Perspectives on the Evolution of Mammals, Birds and Reptiles. Chicago 2006, University of Chicago Press, pp. 153-198
  16. ↑ Laureano Raúl González Ruiz and Gustavo Juan Scillato-Yané: A new Stegotheriini (Mammalia, Xenarthra, Dasypodidae) from the “Notohippidian” (early Miocene) of Patagonia, Argentina. New Yearbook for Geology and Paleontology, Abhandlungen 252 (1), 2009, pp. 81–90
  17. ↑ Maren Möller-Krull, Frédéric Delsuc, Gennady Churakov, Claudia Marker, Mariella Superina, Jürgen Brosius, Emmanuel JP Douzery and Jürgen Schmitz: Retroposed Elements and Their Flanking Regions Resolve the Evolutionary History of Xenarthran Mammals (Armadillos, Anteaters and Sloths). Molecular Biology and Evolution 24, 2007, pp. 2573-2582
  18. ↑ Frederic Delsuc, Mariella Superina, Marie-Ka Tilak, Emmanuel JP Douzery and Alexandre Hassanin: Molecular phylogenetics unveils the ancient evolutionary origins of the enigmatic fairy armadillos. Molecular Phylogenetics and Evolution 62, 2012, pp. 673-680
  19. ↑ Anderson Feijó, Bruce D. Patterson and Pedro Cordeiro-Estrela: Taxonomic revision of the long-nosed armadillos, Genus Dasypus Linnaeus, 1758 (Mammalia, Cingulata). PLoS ONE 13 (4), 2018, p. E0195084 doi: 10.1371 / journal.pone.0195084
  20. ↑ Anselme Gaëtan Desmarest: Tableau méthodique des mammifères. In: Nouveau dictionnaire d'histoire naturelle, appliquée aux arts, principalement à l'agriculture, à l'économie rurale et domestique: Par une société de naturalistes et d'agriculteurs: Avec des figures tirées des trois règnes de la nature. Volume 24, Paris, 1804, pp. 5–38 ( [1] )
  21. ↑ Félix de Azara: Essais sur l'Histoire Naturelle des Quadrupèdes de la Province du Paraguay. Paris, 1801, pp. 1–499 (pp. 186–191) ( [2] )
  22. ^ GWD Hamlett: Identity of Dasypus septemcinctus Linnaeus with notes on some related species. Journal of Mammalogy 20, 1939, pp. 328-336
  23. ↑ Agustín M. Abba and M. Superina: Dasypus hybridus. In: IUCN 2012: IUCN Red List of Threatened Species. Version 2012.2. ( [3] ), last accessed on February 23, 2013

Web links

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