Weasel lemurs

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Weasel lemurs
Red-tailed weasel lemur (Lepilemur ruficaudatus)

Red-tailed weasel lemur ( Lepilemur ruficaudatus )

Systematics
without rank: Euarchonta
Order : Primates (Primates)
Subordination : Wet-nose primates (Strepsirrhini)
Partial order : Lemurs (Lemuriformes)
Family : Weasel lemurs
Genre : Weasel lemurs
Scientific name of the  family
Lepilemuridae
JE Gray , 1870
Scientific name of the  genus
Lepilemur
I. Geoffroy Saint-Hilaire , 1851
Red-shouldered weasel lemur ( Lepilemur aeeclis )

The weasel lemurs ( Lepilemur ) are a genus of primates that belong to their own family, Lepilemuridae. According to the latest findings, the family consists of around 25 species.

description

Weasel lemurs are medium-sized wet - nosed monkeys . They reach a body length of 30 to 35 centimeters, the tail is 26 to 31 centimeters long. Their weight varies between 0.5 and 0.9 kilograms. Their fur is gray-brown or reddish in color on the upper side, the underside is whitish-yellow. The round head sits on a short neck, the eyes are enlarged to adapt to the nocturnal lifestyle, and the ears are also large. The teeth of the animals are characterized by the missing incisors in the upper jaw, the tooth formula is I 0 / 2- C 1 / 1- P 3 / 3- M 3-3, so they have a total of 32 teeth. As in most wet-nosed monkeys, the lower incisors and canines form a tooth comb . The hind legs are elongated due to the jumping movement, but the feet are not. As with all wet-nosed monkeys, all fingers and toes have nails with the exception of the cleaning claw on the second toe.

distribution and habitat

Weasel lemurs live exclusively on the island of Madagascar . Here they inhabit different forest types, both the dry forests of the western and the rainforests of the eastern part of the country.

Way of life

Weasel lemurs are strictly nocturnal and usually stay in the trees. During the day they retreat in tree hollows, sometimes even in the thicket of leaves. At night they go in search of food, where they mainly stay on vertical branches and trunks and move vertically climbing and jumping.

Information on social behavior is contradictory. In addition to individually living animals, there are also reports on family groups, there may be species-specific differences. They inhabit relatively small territories of around 0.2 to 0.5 hectares. The territory is vehemently defended against same-sex intruders, but the territories of males and females can overlap. Since the territories are small, the animals can easily monitor them from a higher branch; they spend parts of the night observing their territorial boundaries and other animals.

nutrition

Weasel lemurs are mainly herbivores; their diet consists mainly of leaves. Since they cannot digest the cellulose, they rely on bacteria in the digestive tract. These live in the greatly enlarged appendix . Similar to the rabbits, they consume their droppings again ( caecotrophy ) in order to get the most out of the components of the food. For leaf-eating mammals, they are small in size. To compensate for the low nutritional value of their food, they take long periods of rest. Their metabolic rate is low compared to that of other primates.

Reproduction

Between September and December, after a gestation period of around 120 to 150 days, a single young is born, which is often raised in a nest in a tree hollow. The boys are weaned at around four months, but stay with their mother until they are one year old. They are sexually mature at around one and a half years. Weasel lemurs in human care can live to be 12 years.

threat

Like all Madagascan wet-nosed monkeys, the weasel lemurs are primarily threatened by the deforestation of the forests and, to a lesser extent, hunting. For many of the newly described species, however, exact data are missing, but since they usually only inhabit small areas, they too are likely to be threatened.

Systematics

The weasel lemurs ( Lepilemur ) are the only representatives of the Lepilemuridae family. Sometimes they are classified in a common family, Megaladapidae, with the extinct giant lemurs of the genus Megaladapis . However, genetic studies show that they are not closely related to Megaladapis .

The number of known species has increased explosively in recent years. By 2005 only eight species were known, a molecular study in 2006 revealed three new species, and a cytogenetic study another. A thorough molecular and morphological study in the same year revealed eleven new species. A research group from the University of Veterinary Medicine Hannover described a new species in 2007. In 2008, researchers from the Omaha Zoo described another species, and another species followed in 2009. A total of 26 species of weasel lemur are known today:

Distribution of the various weasel lemurs in Madagascar

However, this multitude of new species is not undisputed. Particularly in north-western Madagascar, the number of species could decrease again with thorough investigations.

literature

  • Nick Garbutt: Mammals of Madagascar. A Complete Guide. Yale University Press, New Haven CT 2007, ISBN 978-0-300-12550-4 .
  • Thomas Geissmann : Comparative Primatology. Springer-Verlag, Berlin et al. 2002, ISBN 3-540-43645-6 .
  • Ronald M. Nowak: Walker's Mammals of the World. 6th edition. Johns Hopkins University Press, Baltimore MD 1999, ISBN 0-8018-5789-9 .
  • Don E. Wilson, DeeAnn M. Reeder (Eds.): Mammal Species of the World. A taxonomic and geographic Reference. Johns Hopkins University Press, Baltimore MD 2005, ISBN 0-8018-8221-4 .

Individual evidence

  1. ↑ a b c d R. Mittermeier, J. Ganzhorn, W. Konstant, K. Glander, I. Tattersall, C. Groves, A. Rylands, A. Hapke, J. Ratsimbazafy, M. Mayor, E. Louis jr. , Y. Rumpler, C. Schwitzer and R. Rasoloarison: Lemur Diversity in Madagascar. In: International Journal of Primatology 29 (2008), pp. 1607-1656.
  2. ↑ a b c d e f g h i according to Wilson & Reeder (2005)
  3. ↑ a b c d N. Andriaholinirina, J. Fausser, C. Roos, Y. Rumpler, Y. et al .: Molecular phylogeny and taxonomic revision of the sportive lemurs ( Lepilemur , Primates) . In: BMC Evolutionary Biology 6 (17), 2006 PDF
  4. ↑ a b C. Rabarivola, A. Zaramody, J.-L. Fausser, N. Andriaholinirina, C. Roos, C. Zinner, H. Marcel & Y. Rumpler: Cytogenetic and molecular characteristics of a new species of sportive lemur from Northern Madagascar. In: Lemur News 11: 45-49 (2006)
  5. ↑ a b c d e f g h i j k l Edward E. Louis jr. et al .: Molecular and morphological analyzes of the sportive lemurs (Family Megaladapidae: Genus Lepilemur ) reveals 11 previously unrecognized species. In: Texas Tech University Special Publications 49 (2006), pp. 1-49. PDF
  6. ↑ a b c Mathias Craul, Elke Zimmermann, Solofo Rasoloharijaona, Blanchard Randrianambinina, Ute Radespiel: Unexpected species diversity of Malagasy primates ( Lepilemur spp.) In the same biogeographical zone: a morphological and molecular approach with the description of two new species . BMC Evolutionary Biology 2007, 7:83. doi : 10.1186 / 1471-2148-7-83
  7. ↑ a b Runhua Lei et al .: Nocturnal Lemur Diversity at Masoala National Park. Special Publications Museum of Texas Tech University Number 53 (2008) PDF
  8. ↑ a b B. Ramaromilanto, R. Lei, SE Engberg, SE Johnson, BD Sitzmann, and EE Louis, Jr .: Description of a new sportive lemur, Holland's or Mananara-Nord sportive lemur, from Mananara-Nord Biosphere Reserve, Madagascar . In: Museum of Texas Tech University, N. 286 (2009), pp. 1-22.

Web links

Commons : Wieselmakis ( Lepilemur )  - Collection of images, videos and audio files