Pygmy anteaters

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Pygmy anteaters
Common pygmy anteater (Cyclopes didactylus)

Common pygmy anteater ( Cyclopes didactylus )

Systematics
Subclass : Higher mammals (Eutheria)
Superordinate : Sub-articulated animals (Xenarthra)
Order : Tooth arms (pilosa)
Subordination : Anteaters (Vermilingua)
Family : Cyclopedidae
Genre : Pygmy anteaters
Scientific name of the  family
Cyclopedidae
Pocock , 1924
Scientific name of the  genus
Cyclopes
JE Gray , 1821

The dwarf anteaters ( Cyclopes ) are a mammalian species of the suborder anteaters (Vermilingua). They represent the smallest members of this group and at the same time the only ones that live purely on trees. The animals are spread over large areas of Central and South America and mostly live in dense forests. In general, the behavior of the pygmy anteater has not been well researched. They mainly feed on ants and are nocturnal. Females give birth to one young per litter. The entire population is not considered to be endangered, but regionally individual populations can be threatened by habitat destruction. Originally the genus consisted of only one species. Based on the results of a molecular genetic study from 2017, this was split into a total of seven species.

description

Habitus

The dwarf anteaters have a head-trunk length of 18 to 21 cm and a tail length of 18 to 24 cm. The tail always reaches at least the length of the rest of the body - but it is usually much longer. The shoulder height is on average 9.3 cm. The weight is 175 to 400 g. The silky fur is yellowish-brown to gray in color and can often be lighter on the legs. Depending on the type, there is a darker stripe along the center line of the body on the stomach and / or back. This is often more pronounced in animals in the Amazon basin , but is sometimes completely absent in the Central American representatives. Typically, the hair does not have a medullary canal - the animals from Central America are an exception. The head becomes around 5 cm long, the ears are very small and only reach around 0.7 to 1.3 cm in length. In contrast to the other anteaters, the snout is markedly shorter and significantly thicker. On the front feet, the second and third toes are longest, the first and fourth are stunted, and the fifth is completely absent. The two long toes have strong claws. The claws are shortened on the hind feet, which have four toes. The rear foot is about 3.5 cm long.

Skull features

The skull becomes 4.7 to 5.3 cm long and on the brain skull up to 2.3 cm wide. It has a characteristic curved forehead line; in some species there is a noticeable indentation at the transition from the nasal bone to the frontal bone . The base of the skull has a distinctly upward curvature, which is not the case with other anteaters. The strongly regressed zygomatic arches are characteristic . An outstanding feature is the comparatively very short rostrum , which only reaches around 25% of the total skull length. Furthermore, it is clearly pointed at the front. The external ear canal opens either to the front or to the side, depending on the type. The lower jaw has a length of 3 to 3.3 cm. Like all anteaters, pygmy anteaters do not have teeth.

distribution

Distribution area

Pygmy anteaters live in Central and South America . In Central America, the animals come from southern Mexico (in the states of Oaxaca and Veracruz ) to Panama , but there are no reports from El Salvador . The entire northern distribution area extends to Colombia west of the Andes and in a narrow strip into the coastal lowlands of Ecuador . A much larger distribution area is found in northern South America east of the Andes. It is separated from the more northerly by the high mountain range. This distribution area extends from Venezuela to Suriname over the north and central part of Brazil , the east of Colombia and the west of Ecuador and Peru to the north of Bolivia . A population has settled on the island of Trinidad off the north coast . A third distribution area, clearly separated by a 1000 km wide gap, is located in the northern Atlantic forests ( Mata Atlântica ) on the Brazilian east coast of the states of Rio Grande do Norte to Alagoas , although recent studies have shown a significantly larger extent. The two main distribution areas extend over an area of ​​7.6 million square kilometers, while the smaller one covers around 25,000 km². The size of the actually inhabited area is unknown. Deciduous forests, tropical lowland rainforests , gallery forests and mangrove forests serve as preferred habitats . Pygmy anteaters occur from sea level to around 1500 m. In some regions they also live sympathetically with the Tamanduas .

Way of life

Territorial behavior

Sleeping pygmy anteater
Defensive posture of a pygmy anteater

Little research has been done into the pygmy anteater's way of life. They are pure tree dwellers who, as excellent climbers, mainly stay in the branches of the trees. The moveable front and rear feet, but also the grasping tail, are used for climbing . The movements are sedate and slow. The pygmy anteaters are nocturnal. During the day they lie down to sleep on a fork in the branches by clenching their feet and rolling their tails around the branch; in this position they sleep an average of 12 hours a day. The animals maintain territories which for the males cover about 5 to 11 ha, for the females an average of 2.8 ha. The territories of the males do not overlap, but do overlap with those of the females. During their nocturnal foraging for food, they cover up to 300 m, but on average it is usually around 74 m. When moving on level ground, the long claws of the front feet are folded down so that the animal walks on tiptoe. When there is an impending danger, which is usually indicated by the wobbling of the branches, an animal clings to the branches with hind legs and tail and lifts the front legs so that the bare lower surfaces are visible and the long claws are next to the snout. A direct attack is then countered with powerful blows and blows with the claws.

nutrition

The pygmy anteaters' diet consists exclusively of insects , preferably ants . Mainly representatives of the genera Camponotus , Crematogaster , Dolichoderus or Pheidole are eaten, with larvae making up about 10%. In some regions, such as the Brazilian state of Maranhão , Solenopsis dolichoderus are particularly common and can make up 48% or 26% of the food quantity. In the Amazon basin , on the other hand, crematogaster is a frequent source of food , among other things, and made up up to 72.4% of the total amount of four examined droppings . Most of the ant representatives from the food spectrum of pygmy anteaters live on trees or bushes and build their nests in tree hollows. Occasionally an animal ingests beetles or hymenoptera . It is possible that pygmy anteaters take an opportunistic approach to food intake , as the excrement residues examined each contained a large number of different species of ants and some of the remains of other insects. A total of 700 to 5000 insects are eaten per day, an average of 2200. A seasonal change in diet is not known. The dwarf anteaters use their powerful claws to tear open their burrows while searching for food and lick their prey with their long sticky tongues. Sometimes they only balance their hind feet on the branches.

Reproduction

A female gives birth to one young per litter. There may be two litters over the year. The young animal, which already has a fur coat after birth, is hidden in a leaf nest or in a tree hole and both parents participate in the rearing. First of all, a young animal consumes mother's milk, when it reaches about a third of the weight of the adult animal, solid food is consumed. Weaning begins when the young weighs about half as much as one of the parent animals. Sometimes the male carries the young on his back. Eating mother animals leave their young for up to eight hours. Nothing is known about life expectancy in the wild; animals in captivity lived for a maximum of five years.

Parasites

External parasites that attack the pygmy anteaters include ticks of the genus Amblyomma . The internal parasites include coccidia such as Eimeria and roundworms , mainly Cyclobulura and some members of the Heligmosomidae family . The animals are also carriers of the yellow fever virus .

Systematics

Internal systematics of the recent anteaters according to Delsuc et al. 2012
  Vermilingua  
  Cyclopedidae  

 Cyclopes


  Myrmecophagidae  
  Tamandua  

 Tamandua mexicana


   

 Tamandua tetradactyla



   

 Myrmecophaga




Template: Klade / Maintenance / Style
Historical illustration of Cyclopes dorsalis from the first description by John Edward Gray in 1865

The dwarf anteaters form a genus from the suborder of the anteaters (Vermilingua). Within this it is the only living member of the family Cyclopedidae today. The family is the sister taxon of the other anteaters. These include the genera Myrmecophaga and Tamandua , together they form the family of Myrmecophagidae . According to molecular genetic studies, the Cyclopedidae and the Myrmecophagidae separated in the Middle Eocene around 38 million years ago. The pygmy anteaters have no significant fossil record. An ancestor is paleomyrmidon from the Pliocene .

Originally, within the genus Cyclopes, with Cyclopes didactylus only one species was known (the pygmy anteater), named after the hands with the two clawed fingers. Seven subspecies were identified within this species, the differentiation of which was based on morphological features:

  • C. d. catellus Thomas , 1928
  • C. d. didactylus ( Linnaeus , 1758)
  • C. d. dorsalis ( Gray , 1865)
  • C. d. eva Thomas , 1902
  • C. d. ida Thomas , 1900
  • C. d. melini Lönnberg , 1928
  • C. d. mexicanus Hollister , 1914

This classic breakdown according to external characteristics was contrasted with genetic analyzes of the pygmy anteater from 2017, which took into account individuals from its entire South American distribution area. A total of five subspecies were distinguished in the region, but according to the studies, the population there is composed of seven haplotype groups, each of which forms monophyletic lines. The two historically oldest haplotype groups were found in the south and southwest of today's distribution area. They separated from the other lines as early as the Middle Miocene 13.5 million years ago, whereby climatic changes as a result of a stronger elevation of the central and northern Andes may have played a decisive role. Further diversification of the pygmy anteater then took place during the course of the Pliocene. The results of the genetic investigations led to the consideration of a revision of the classic classification into the known subspecies.

Internal systematics of pygmy anteaters according to Miranda et al. 2017
  Cyclopes  


 Cyclopes rufus


   

 Cyclopes thomasi



   

 Cyclopes ida


   

 Cyclopes xinguensis


   

 Cyclopes dorsalis


   

 Cyclopes didactylus






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No genetic data are yet available for Cyclopes catellus

Another genetic examination, combined with morphological studies, also from 2017, included a total of more than 280 individuals from all of Central and South America. From a genetic point of view, the analyzes were able to confirm the previous result. According to this, six different populations can be genetically distinguished, which only partially correspond to the subspecies. Morphological and anatomical deviations were found, among other things, in the variable formation of the back and abdominal stripes, in the structure of the hair and in individual skull features. No DNA could be obtained for a further seventh population from the southwestern distribution area (Bolivia), but it also shows striking external abnormalities. These seven groups were raised to species status by the editors; they are made up of four former subspecies and three newly described species. Thus, the genus of dwarf anteaters now consists of the following species:

The first representative of the pygmy anteaters was introduced by Linnaeus in 1758 as Myrmecophaga didactyla . He separated this from the great anteater ( Myrmecophaga tridactyla ) and from the southern Tamandua ( Tamandua tetradactyla ) on the basis of the number of clawed forefoot toes. Linnaeus gave “America australi” as the type locality. The genus name Cyclopes was introduced by John Edward Gray in 1821, but he only brought it indirectly in connection with the species didactylus ("Anteater; Cyclopes, G. Myrmecophaga didactyla. Lin."). The first correct use of the name as Cyclopes didactylus was made by Oldfield Thomas in 1900. The generic name Cyclopes is made up of the Greek words κυκλῶ ( cyclo , "circle") and πούς ( poús , "foot") and refers to the Ability of animals to close their feet around a branch. The name Cyclothurus , which he established as the noun nudum in 1825 , also comes from Gray . It was only René Primevère Lesson who brought her in connection with the pygmy anteater in 1842 as Cyclothurus didactyla . Cyclothurus was used as a scientific name for the pygmy anteater , especially in the further course of the 19th century. The name of the subfamily Cyclothurinae, coined by Theodore Gill in 1872, which was later raised to the level of the family, is derived from it. The family name Cyclopedidae, which is valid today, goes back to Reginald Innes Pocock from 1924.

threat

Since pygmy anteaters are very shy and therefore rarely observed, only a few statements can be made about the degree of endangerment. In general, the deforestation of the tropical rainforests and Atlantic coastal forests is a threat, as it restricts the habitats of animals. For the eastern population on the Atlantic coast in particular, the large-scale cultivation of sugar cane leads to major habitat losses , so that possibly only 5% of the habitat there is intact. For the main distribution area, however, it is assumed that the pygmy anteaters are still relatively common. The IUCN currently (2017) only considers the total population under the name Cyclopes didactylus as “not endangered” ( least concern ). The eastern coastal population, on the other hand, is in the “ data deficient ” category - it is very likely that there was a decline in the population. In some areas, pygmy anteaters are kept as pets, but they usually do not survive long in captivity. In addition, there are only a few zoological institutions that present pygmy anteaters.

literature

  • Virginia Hayssen, Flávia Miranda and Bret Pasch: Cyclopes didactylus (Pilosa: Cyclopedidae). Mammalian Species 44 (1), 2012, pp. 51-58
  • Flávia R. Miranda, Daniel M. Casali, Fernando A. Perini, Fabio A. Machado and Fabrício R. Santos: Taxonomic review of the genus Cyclopes Gray, 1821 (Xenarthra: Pilosa), with the revalidation and description of new species. Zoological Journal of the Linnean Society 20, 2017, pp. 1–35 doi: 10.1093 / zoolinnean / zlx079
  • Flávia R. Miranda: Cyclopedidae (Silky Anteaters). Don E. Wilson and Russell A. Mittermeier (Eds.): Handbook of the Mammals of the World. Volume 8: Insectivores, Sloths, Colugos. Lynx Edicions, Barcelona 2018, pp. 92-102 ISBN 978-84-16728-08-4
  • Flávia R. Miranda: Cyclopedidae (Silky anteaters). 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. 92-102 ISBN 978-84-16728-08-4

Individual evidence

  1. ↑ a b c d e f g h i Virginia Hayssen, Flávia Miranda and Bret Pasch: Cyclopes didactylus (Pilosa: Cyclopedidae). Mammalian Species 44 (1), 2012, pp. 51-58
  2. ^ A b Hugh H, Genoways and Robert M. Timm The Xenarthrans of Nicaragua. Mastozoologia Neotropical 10 (2), 2003, pp. 231-253
  3. ↑ a b c d Flávia R. Miranda, Daniel M. Casali, Fernando A. Perini, Fabio A. Machado and Fabrício R. Santos: Taxonomic review of the genus Cyclopes Gray, 1821 (Xenarthra: Pilosa), with the revalidation and description of new species. Zoological Journal of the Linnean Society 20, 2017, pp. 1-35
  4. ↑ a b c d e Flávia R. Miranda: Cyclopedidae (Silky anteaters). 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. 92-102 ISBN 978-84-16728-08-4
  5. ↑ Flávia Miranda and Mariella Superina: New distribution record of the silky anteater Cyclopes didactylus (Pilosa, Cyclopedidae) in coastal Northeastern Brazil. Mastozoología Neotropical, 17 (2), 2010, pp. 381-384
  6. ↑ Flávia Miranda and DA Meritt Jr .: Cyclopes didactylus, main population. Edentata 11 (2), 2010, p. 99
  7. ↑ Flávia Miranda and Mariella Superina: Cyclopes didactylus, Northeastern Brazil subpopulation. Edentata 11 (2), 2010, p. 101
  8. ↑ Kenneth A. Nagy and G. Gene Montgomery: Field metabolic rate, water flux and food consumption by free-living silky anteaters (Cyclopes didactylus) in Panama. Edentata 13, 2012, pp. 61-65
  9. ↑ Flávia Miranda, Roberto Veloso, Mariella Superina and Fernando José Zara: Food Habits of Wild Silky Anteaters (Cyclopes didactylus) of São Luis do Maranhão, Brazil. Edentata 8-10, 2009, pp. 1-5
  10. ^ Robin C. Best and Ana Y. Harada: Food habits of the silky anteater (Cyclopes didactylus) in the central Amazon. Journal of Mammalogy 66 (4), 1985, pp. 780-781
  11. ↑ a b Lizette Bermúdez Larrazábal: Adaptación al cautiverio del serafín del platanar (Cyclopes didactylus). Edentata 12, 2011, pp. 45-52
  12. ↑ Marcelo B. Labruna, Luís Marcelo A. Camargo, Flávio A. Terrassini, Teresinha TS Schumaker and Erney P. Camargo: Notes on Parasitism by Amblyomma humerale (Acari: Ixodidae) in the State of Rondônia, Western Amazon, Brazil. Journal of Medical Entomology 39 (6), 2002, pp. 814-817. 2002
  13. ↑ a b Frédéric 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, 673-680
  14. ↑ Frédéric Delsuc, Sergio F Vizcaíno and Emmanuel JP Douzery: Influence of Tertiary paleoenvironmental changes on the diversification of South American mammals: a relaxed molecular clock study within xenarthrans. BMC Evolutionary Biology 4 (11), 2004, pp. 1-13
  15. ↑ 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
  16. ^ Sue D. Hirschfeld: A new fossil anteater (Edentata, Mammalia) from Colombia, SA and evolution of the Vermilingua. Journal of Paleontology 50 (3), 1976, pp. 419-432
  17. Jump up ↑ Raphael Teodoro Franciscani Coimbra, Flávia Regina Miranda, Camila Clozato Lara, Marco Antônio Alves Schetino and Fabrício Rodrigues dos Santos: Phylogeographic history of South American populations of the silky anteater Cyclopes didactylus (Pilosa: Cyclopedidae). Genetics and Molecular Biology 40 (1), 2017, pp. 40-49 doi: 10.1590 / 1678-4685-GMB-2016-0040
  18. ↑ John Edward Gray: On the natural arrangement of vertebrose animals. London Medical Repository 15, 1821, pp. 297-310 (305) ( [1] ; PDF; 898 kB)
  19. ↑ Oldfield Thomas: Descriptions of new rodents from western South America. Annals and Magazine of Natural History 7 (6), 1900, pp. 294-302 ( [2] )
  20. ↑ John Edward Gray: An outline of an attempt at the disposition of Mammalia into tribes and families, with a list of the genera apparently pertaining to each tribe. Annals of Philosophy 10, 1825, pp. 337-344 ( [3] )
  21. ^ René Primevère Lesson: Nouveau tableau du règne animal. Première classe. Mammifères. Paris, 1842, pp. 1–204 (p. 152) ( [4] )
  22. ^ Theodore Gill: Arrangement of the families of mammals with analytical tables. Washington, 1872, pp. 1–98 (p. 23) ( [5] )
  23. ^ Alfred L. Gardner: Suborder Vermilingua Illiger, 1811. in: Alfred L. Gardner (Ed.): Mammals of South America, Volume 1: Marsupials, Xenarthrans, Shrews, and Bats. University of Chicago Press, 2008, pp. 168-178
  24. ↑ Flávia R. Miranda, DA Meritt, DG Tirira and M. Arteaga: Cyclopes didactylus. The IUCN Red List of Threatened Species 2014. e.T6019A47440020 ( [6] ); last accessed on December 7, 2018
  25. ↑ Flávia R. Miranda and Mariella Superina: Cyclopes didactylus Northeastern Brazil subpopulation. The IUCN Red List of Threatened Species 2014. e.T173393A47444393 ( [7] ); last accessed on December 7, 2018

Web links

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