Tamanduas
Tamanduas | ||||||||||||
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![]() Northern Tamandua ( Tamandua mexicana ) in Corcovado National Park in Costa Rica |
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Systematics | ||||||||||||
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Scientific name | ||||||||||||
Tamandua | ||||||||||||
Gray , 1825 |
The Tamanduas ( Tamandua ) are a genus with two species from the suborder of the anteater (Vermilingua), which is native to Central and South America . Sometimes they are also referred to as little anteaters . With their partly ground-dwelling and partly tree-dwelling way of life, they mediate between the ground-dwelling great anteater and the dwarf anteater , which only lives in trees . Like them, the Tamanduas live solitary and feed on state-building insects . The population of the two Tamandua species is not endangered.
features
Habitus
Tamanduas are medium-sized anteaters and with a head-to-trunk length of 47 to 88 cm and a 40 to 67 cm long tail, they are significantly smaller than their relative, the great anteater ( Myrmecophaga tridactyla ). They reach a weight of 2 to 7 kg. The basic color of the fur dress is beige to light brown. On it is a black vest pattern that begins at the shoulder and encloses the torso behind the front legs; This drawing is more pronounced in the Northern Tamandua and stands out clearly from the basic color, in the Southern Tamandua it is more indistinct and can also be missing. A sexual dimorphism is hardly developed and can only be identified in individual populations on the basis of individual skull features. Like all anteaters, they are characterized by their long, narrow snouts, the mouth of which is only the thickness of a pencil. They are toothless, but have a 40 cm long and thin tongue that is covered with sticky secretion and with which they ingest their food. Tamanduas have four toes on their front feet that are equipped with long, sharp claws, of which the third claw is greatly enlarged; the fifth toe is only rudimentarily developed. When running, the animals cannot roll over their front paws, but only put pressure on the front tips and the outside to protect the long claws. The hind feet have five toes with much smaller claws.
Skull and skeletal features
The elongated skull with an elongated rostrum is typical , whereby the nasal bone - in contrast to the giant anteater - does not reach the length of the frontal bone . Another characteristic is the reduced cheekbone arches . As with some other secondary articulated animals , such as the armadillos , a bone formation known as the septomaxilla (os nariale) occurs in the anterior region of the nasal cavity , which otherwise only occurs in phylogenetically older mammals and reptiles . In contrast to the armadillos, this septomaxilla is built somewhat differently and more simply.
On the spine, xenarthric joints occur primarily in the posterior thoracic and lumbar vertebrae , and secondary joints on the lateral spinous processes, which give the secondary articular animals (xenarthra) their name. There are several modifications in the anterior musculoskeletal system that allow significantly increased mobility, which is mainly used in the search for food and in defense behavior. This includes, above all, the widening of the shoulder blade and the lower joint end of the humerus , which continue to offer additional starting points for strong muscles and also increase the moments of movement of the front legs.
distribution and habitat
Tamanduas occur in Central and South America . The distribution area extends from southern Mexico to northern Argentina and Uruguay . Although they have been detected up to heights of 2000 m, they are rare exceptions there and prefer the flatlands. A wide variety of habitats are colonized by these anteaters. In addition to rain, dry and mangrove forests, these are also tree savannahs and cultivated land.
Way of life
Territorial behavior
Tamanduas are both diurnal and nocturnal, but rest around noon. Their activity time is around eight hours a day, moving on the ground as well as in the trees. On the ground, however, they are rather slow and clumsy, especially in comparison to the more mobile giant anteater. Tamanduas can also swim. As territorial loners, they mark their territories with an anal gland secretion that exudes a strong odor over several meters. The range of action of a tamandua can vary between 25 and 375 hectares depending on the region. The animals spend resting times in tree hollows or abandoned animal structures, for example armadillos , which they occasionally expand. Many larger predators occasionally prey on tamanduas, including jaguars and harpies . If a Tamandua is threatened, it stands with its back to a tree on its hind legs and tries to repel the attacker with blows from its sharp claws.
nutrition
The diet of the Tamanduas consists almost exclusively of termites and ants as well as other state-building insects . The percentage of the individual food components can, however, be very different from region to region. The nests are felt with the sense of smell, dug up with the sharp claws of the front feet and plundered with the tongue. Both in trees and on the ground, nests are known to be food resources. The duration of feeding on the individual nests is usually relatively short due to the chemical defense of the insects, which is why several colonies have to be visited during the day (50 to 80 in the northern Tamandua). As a result, the animals only remove a relatively small amount of insects each time, so that no permanent damage is inflicted on the colonies. In addition to insects, tamanduas occasionally eat fruit or grass as complementary foods.
Reproduction
Male tamanduas find females by smell. A male ready to reproduce follows a female for a while. Both partners stop again and again and sniff each other. Finally, the male mounts the female, clasps his trunk with his front legs and initiates copulation. Then the male goes on his way again. There are contradicting data about the gestation period, suggesting 130 to 150 days on the one hand and 160 to 190 days on the other. Only one young is born per litter. This is usually left behind in a tree hole during the mother's excursions, but sometimes it is also carried around on her back. Tamanduas lived to be 9½ years old in captivity; the maximum age of wild animals is unknown.
Systematics
Internal systematics of the recent anteaters according to Delsuc et al. 2012
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Tamandua is a genus within the Myrmecophagidae family . The closest relative of the Tamanduas is the great anteater ( Myrmecophaga tridactyla ), which forms their sister taxon . Somewhat more distantly related are the pygmy anteaters ( Cyclopes ), which form the family Cyclopedidae. Both families together form the subordination of the anteaters (Vermilingua). The separation of the two genera Tamandua and Myrmecophaga took place after molecular genetic studies in the Upper Miocene about 13 million years ago. Cyclopes, on the other hand, split off from this line in the Middle Eocene around 38 million years ago.
Today two types of tamandua are distinguished:
- Northern Tamandua ( Tamandua mexicana Saussure , 1860); Central America , northwestern South America
- Southern Tamandua ( Tamandua tetradactyla Linnaeus , 1758); northern and central South America
The distinction between the two types is mostly based on external, but more strongly varying characteristics. According to genetic studies from 2015, the division is not clear.
The genus name Tamandua as a member of the anteater was first used by John Edward Gray in 1825 without mentioning a specific species; In this publication, Gray also viewed the anteaters as a subfamily of the armadillos . Already in 1821 Gray had used the term "Tamandua" as a specific epithet for Myrmecophaga tamandua . The Tamanduas were believed to be a single species until the very recent past. In 1758, Carl von Linné described southern Tamandua as Myrmecophaga tetradactyla ("four-toed anteater"). He continued to put Myrmecophaga tridactyla , the great anteater with three and Myremcophaga didactyla , the dwarf anteater with two clawed toes on each front paw to the side. The now correct, scientific name Tamandua tetradactyla for the four-toed (southern) Tamandua was also introduced by John Edward Gray in 1843. A division of the tamanduas into two types did not take place until 1975. For this division, primarily anatomical details in the skull structure and individual external features were decisive.
etymology
The name "Tamandua" is borrowed from the Tupi language of Brazil and is made up of the words tacy ("ant") and monduar ("to catch"). The word was conveyed to Europe via Portuguese ( tamanduá ). Generic names created later for the Tamandua such as Uroleptes and Dryoryx are invalid. In Brazil, the term "Tamandua" is used both in Portuguese and in some indigenous languages (here almost exclusively) for the giant anteater, common names are Tamanduá-bandeira or Tamanduá-guasú .
Tribal history
The genus Tamandua can be found fossil for the first time in the Pleistocene of South America, despite the long-time separation of the Tamanduas from the great anteater, which was determined by molecular genetics; it is also quite well documented from the Holocene . Protamandua , which occurs in the Santacruzian around 16 million years ago, is considered to be the predecessor of the two anteater genera mentioned . In terms of its size, however, it represents a median form between Tamandua and Cyclopes , but its habitus is more generalized. Neotamandua dated more recently , which is proven both from the Upper Miocene of the La Venta Formation in Colombia and from the Pliocene of the Araucano Formation in Argentina . According to morphological studies, this is probably more closely related to Myrmecophaga .
People and tamanduas
Tamanduas are relatively common in large parts of their range. The IUCN classifies both species as not endangered. The fur is considered worthless, the meat is only eaten by a few Indian peoples. The destruction of the rainforest may also be less of a problem for the Tamanduas, as they can also cope in secondary forests and cultivated landscapes. Tamanduas often die on streets where they are run over by cars. So while tamanduas are common overall, in individual countries they are rare enough that they have been placed under strict protection. This is the case in Mexico , Guatemala , Peru and Argentina .
literature
- Alessandra Bertassoni: Myrmecophagidae (Anteaters). In: Don E. Wilson, Russell A. Mittermeier (eds.): Handbook of the Mammals of the World. Volume 8: Insectivores, Sloths and Colugos. Lynx Edicions, Barcelona 2018, ISBN 978-84-16728-08-4 , pp. 74-90.
- Virginia Hayssen: Tamandua tetradactyla. In: Mammalian Species. 43 (875), 2011, pp. 64-74.
- Daya Navarrete, Jorge Ortega: Tamandua mexicana. In: Mammalian Species. 43 (874), 2011, pp. 56-63.
- Ronald M. Nowak: Walker's Mammals of the World. 2 volumes. 6th edition. Johns Hopkins University Press, Baltimore MD et al. 1999, ISBN 0-8018-5789-9 .
Individual evidence
- ↑ Ronald M. Nowak: Walker's Mammals of the World . Johns Hopkins University Press, 1999, ISBN 0-8018-5789-9 .
- ↑ a b c d e f g h Virginia Hayssen: Tamandua tetradactyla. In: Mammalian Species. 43 (874), 2911, pp. 64-74.
- ↑ a b c d e f Paul Smith: Southern Tamandua Tamandua tetradactyla (Linnaeus 1758). In: Fauna of Paraguay. 3, 2007, pp. 1-15.
- ↑ a b c d e Alessandra Bertassoni: Myrmecophagidae (Anteaters). In: Don E. Wilson, Russell A. Mittermeier (eds.): Handbook of the Mammals of the World. Volume 8: Insectivores, Sloths and Colugos. Lynx Edicions, Barcelona 2018, ISBN 978-84-16728-08-4 , pp. 74-90.
- ↑ U. Zeller, JR Wible, M. Eisner: New Ontogenetic Evidence on the Septomaxilla of Tamandua and Choloepus (Mammalia, Xenarthra), with a Reevaluation of the Homology of the Mammalian Septomaxilla. In: Journal of Mammalian Evolution. 1 (1), 1993, pp. 31-46.
- ↑ Bruce K. Taylor: The Anatomy of the Forelimb in the Anteater (Tarnandua) and Its Functional Implications. In: Journal of Morphology. 15, 1978, pp. 347-368.
- ^ Helen Esser, Danielle Brown, Yorick Liefting: Swimming in the Northern Tamandua (Tamandua mexicana) in Panama. In: Edentata. 11, 2010, pp. 70-72.
- ↑ David Matlaga: Mating Behavior of the Northern Tamandua (Tamandua mexicana) in Costa Rica. In: Edentata. 7, 2006, pp. 46-48.
- ↑ a b 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, pp. 673-680
- ↑ Frédéric Delsuc, Sergio F Vizcaíno, Emmanuel JP Douzery: Influence of Tertiary paleoenvironmental changes on the diversification of South American mammals: a relaxed molecular clock study within xenarthrans. In: BMC Evolutionary Biology. 4 (11), 2004, pp. 1-13.
- ↑ 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.
- ^ John Edward Gray, An outline of an attempt at the disposition of Mammalia into tribes and families, with a list of the genera apparently appertaining to each tribe. In: Annals of Philosophy NS. 10, 1825, pp. 337–344 (p. 343) ( rhinoresourcecenter.com ; PDF; 609 kB)
- ↑ John Edward Gray: On the natural arrangement of vertebrose animals. In: London Medical Repository. 15, 1821, pp. 297-310 (305)
- ↑ Ralph M. Wetzel: The species of Tamandua Gray (Edentata, Myrmecophagidae). In: Proceedings of the Biological Society of Washington. 88 (11), 1975, pp. 95-112.
- ↑ Mariella Superina, John M. Aguiar: A Reference List of common names for the edentates. In: Edentata. 7, 2006, pp. 33-44.
- ^ Sue D. Hirschfeld: A new fossil anteater (Edentata, Mammalia) from Colombia, SA and evolution of the Vermilingua. In: Journal of Paleontology. 50 (3), 1976, pp. 419-432.
- ↑ Timothy J. Gaudin, Daniel G. Branham: The Phylogeny of the Myrmecophagidae (Mammalia, Xenarthra, Vermilingua) and the Relationship of Eurotamandua to the Vermilingua. In: Journal of Mammalian Evolution. 5 (3), 1998, pp. 237-265.
- ↑ Mariella Superina, Flávia Regina Miranda, Manuel Agustín Abba: The The 2010 Anteater Red List assessment. In: Edentata. 11 (2), 2010, pp. 96-114.