Little Vespermaus

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Vesper mouse
Vesper mouse

Vesper mouse

Systematics
Family : Burrowers (Cricetidae)
Subfamily : Sigmodontinae
Oryzomyalia
Tribe : Phyllotini
Genre : Vesper mice ( Calomys )
Type : Vesper mouse
Scientific name
Calomys laucha
( Fischer , 1814)

The Small Vesper mouse ( Calomys laucha ) is a kind of snack mice within the agitators (Cricetidae), which occurs in parts of South America.

features

The little Vespermaus reaches a head-trunk length of 5.6 to 6.7 centimeters and a tail length of 4.5 to 5.4 centimeters with a weight of about 11 to 19 grams. The ear length is 8 to 11.7 millimeters and the rear foot length 13.4 to 15 millimeters. It is the smallest species within the genus of Vesper mice. The back color is gray to gray-white with brown to golden-brown tints. A dark back band runs from the back of the head over the back to the back of the trunk. The sides of the body are lighter and also interspersed with brown hair. A sandy brown line delimits the sides of the body from the light, whitish side of the abdomen. In some populations , the throat and chin are completely white in color. Behind the ears there is a light postauricular spot and, especially in individuals in drier habitats, there is often another sand-colored spot in front of the ears. The tail is two-colored with a brown top and a light underside. It never reaches more than 43% of the head-trunk length in length. Adult females have eight to ten teats .

distribution

This species is found in central and southeastern regions of South America in southeastern Bolivia , western Paraguay , northern and central Argentina, and the extreme south of Brazil .

Way of life

The little Vespermaus lives in dry grasslands, on the edges of forests and in the edge areas of agricultural land as well as in dry to semi-arid bush regions. In general, it feeds primarily on parts of plants and above all on seeds of various grasses (granivores). It lives terrestrially on the ground and is primarily active at night and at dawn.

The average length of the female cycle in the little Vesper mouse is six to eight days. Mating occurs throughout the year and the females can become pregnant throughout the year, with studies in Argentina showing around 40% of pregnant females occurring between October and May. The gestation period is between 21 and 23 days, an average of about 21.5 days. The female gives birth to between 1 and 6 pups, an average of 3.7 pups.

Systematics

The little vesper mouse is considered to be an independent species within the vesper mice (genus Calomys ). It was first scientifically described in 1814 by the German naturalist Gotthelf Fischer von Waldheim under the name Mus laucha , although he did not give any location for the individual types . The American mammalogue Philip Hershkovitz limited the Terra typica in 1962 to the region around Asunción in Paraguay. In 2017, a working group led by Pablo Teta determined a neotype and a new terra typica in the Estación Experimental Regional Agropecuaria Pergamino in Pergomino , Buenos Aires , in Argentina. In the past, other species that are now viewed as separate species were considered synonyms of this species, including Calomys hummelincki , Calomys muskulinus and Calomys tener .

Currently, no subspecies are distinguished within the species, but there are probably two geographically isolated populations and forms of the species. Wilson & Reeder 2005, on the other hand, listed five subspecies C. l. bimaculatus , C. l. bonariensis , C. l. dubius , C. l. gracilipes and C. l. pusillus as a subspecies.

Danger

The IUCN classifies the little Vesper mouse as Least Concern . The classification is based on their widespread distribution, their occurrence and on agricultural areas as well as the population trends, which are slightly declining, but not threatening the existence. There are no known threats to the species' existence.

supporting documents

  1. a b c d e f g C. Denys, PJ Taylor, KP Aplin et al .: Small Vesper Mouse Calomys laucha. In: Don E. Wilson, TE Lacher, Jr., Russell A. Mittermeier (Eds.): Handbook of the Mammals of the World: Rodents 2. (HMW, Volume 7) Lynx Edicions, Barcelona 2017, ISBN 978-84- 16728-04-6 , p. 515.
  2. Pablo Teta, Raúl E. González-Ittig, Enrique M. González, Ulyses FJ Pardiñas, Jorge Salazar-Bravo: Notes on the taxonomy of Calomys laucha (Rodentia, Cricetidae), with the designation of a neotype. Mastozoologia Neotropical 24 (2), December 2017; Pp. 419-429. ( Full text )
  3. a b Calomys laucha. In: Don E. Wilson , DeeAnn M. Reeder (Eds.): Mammal Species of the World. A taxonomic and geographic Reference. 2 volumes. 3. Edition. Johns Hopkins University Press, Baltimore MD 2005, ISBN 0-8018-8221-4 .
  4. a b Calomys laucha in the endangered Red List species the IUCN 2019. Posted by: A. Christoff, M. Weksler, E. Vieira, G. D'Elia, JP Jayat, U. Pardinas, 2008. Accessed November 18 2019.

literature

  • C. Denys, PJ Taylor, KP Aplin et al .: Small Vesper Mouse Calomys laucha. In: Don E. Wilson, TE Lacher, Jr., Russell A. Mittermeier (Eds.): Handbook of the Mammals of the World: Rodents 2. (HMW, Volume 7) Lynx Edicions, Barcelona 2017, ISBN 978-84- 16728-04-6 , p. 515.

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