| Cursor Grass Mouse | |
|---|---|
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Rodentia |
| Family: | Cricetidae |
| Subfamily: | Sigmodontinae |
| Genus: | Akodon |
| Species: | A. cursor |
| Binomial name | |
| Akodon cursor Winge, 1888 | |
The cursor grass mouse, or cursorial akodont (Akodon cursor), is a sigmodontine rodent from South America. [2]
The cursor grass mouse is a moderately sized rodent, with a head-body length of 11 to 13 centimetres (4.3 to 5.1 in), and a tail 8 to 11 centimetres (3.1 to 4.3 in) long. Males are larger than females, weighing an average of 54 grams (1.9 oz), compared with 43 g (1.5 oz) for females. They have a typical mouse-like appearance, with short whiskers and stubby claws on the feet. They have dark to golden brown fur over most of their body, with paler greyish or yellowish underparts. Some have a whitish spot between the ears, but this is not present on all individuals. [3]
Cursor grass mice are members of the A. cursor species group, and very similar in appearance to other members of the group. In particular, they cannot easily be distinguished from the closely related montane grass mouse, which inhabits neighbouring regions to the immediate south. Although the cursor grass mouse is, on average, slightly larger than the montane species, there is too much overlap for this to be a reliable guide. Instead, they can most readily be distinguished by the presence of a gall bladder in A. cursor (absent in the montane species), by karyotypic analysis, or by means of PCR based techniques. [3] [4] [5] [6]
The exact geographic range of the cursor grass mouse is disputed. It is definitively known to inhabit eastern Brazil from Paraíba to Paraná, where it lives in patches of tropical Atlantic Forest and restinga scrubland at elevations from sea level to 1,170 metres (3,840 ft). Some sources [1] also report it as being found further south, in extreme southern Brazil, in eastern Paraguay, and in northern Argentina. [7] These latter sources lack a definitive genetic analysis of the individuals identified, and it has been argued that they may represent members of other species, such as the montane grass mouse. [3] No subspecies are recognised.
Cursor grass mice are omnivorous. Their primary diet consists of small arthropods, especially Hymenoptera, beetles, and spiders; this is supplemented by seeds of Cecropia and other plants. [8] They search for food through leaf litter and patches of dense vegetation, and are strictly terrestrial. [9] [10] Individuals have a home range of 0.1 to 0.7 hectares (0.25 to 1.73 acres), with the ranges of males being larger than those of females. [11] Although the size of their home ranges does not change, the population density of cursor grass mice becomes significantly higher during the rainy season, when insects are most abundant. [12]
Cursor grass mice breed throughout the year, although most births occur during the dry season between June and September. Pregnant females construct globular nests, and give birth to a litter of two to nine young, with an average of four, after a gestation period of 23 days. [3] [13]
This species is particularly important for public health since it has been implied as a Hantavirus reservoir. [14]
A cell line derived from a liposarcoma in a cursor grass mouse has been used by biomedical scientists in the construction of a panel for the identification of human chromosomes in hybrid cells. [15]
The Muroidea are a large superfamily of rodents, including mice, rats, voles, hamsters, lemmings, gerbils, and many other relatives. Although the Muroidea originated in Eurasia, they occupy a vast variety of habitats on every continent except Antarctica. Some authorities have placed all members of this group into a single family, Muridae, due to difficulties in determining how the subfamilies are related to one another. Many of the families within the Muroidea superfamily have more variations between the families than between the different clades. A possible explanation for the variations in rodents is because of the location of these rodents; these changes could have been due to radiation or the overall environment they migrated to or originated in. The following taxonomy is based on recent well-supported molecular phylogenies.
The rodent subfamily Sigmodontinae includes New World rats and mice, with at least 376 species. Many authorities include the Neotominae and Tylomyinae as part of a larger definition of Sigmodontinae. When those genera are included, the species count numbers at least 508. Their distribution includes much of the New World, but the genera are predominantly South American, such as brucies. They invaded South America from Central America as part of the Great American Interchange near the end of the Miocene, about 5 million years ago. Sigmodontines proceeded to diversify explosively in the formerly isolated continent. They inhabit many of the same ecological niches that the Murinae occupy in the Old World.
The New World rats and mice are a group of related rodents found in North and South America. They are extremely diverse in appearance and ecology, ranging from the tiny Baiomys to the large Kunsia. They represent one of the few examples of muroid rodents in North America, and the only example of muroid rodents to have made it into South America.
Akodon is a genus consisting of South American grass mice. They mostly occur south of the Amazon Basin and along the Andes north to Venezuela, but are absent from much of the basin itself, the far south of the continent, and the lowlands west of the Andes. Akodon is one of the most species-rich genera of Neotropical rodents. Species of Akodon are known to inhabit a variety of habitats from tropical and tropical moist forests to altiplano and desert. Fossils are known from the late Pliocene onwards.
Bibimys is a genus of new world rats. Commonly known as the crimson-nosed rats, there are three species:
The Brazilian shrew mouse, also known as the blarinine akodont, is a rodent in the tribe Akodontini from the Atlantic Forest of eastern and southeastern Brazil. It is the only species in the genus Blarinomys. Phylogenetic analysis suggest that there are two clear geographical clades, a northeastern and southeastern.
Necromys is a genus of South American sigmodontine rodents allied to Akodon. This genus has also been known as Cabreramys or more recently Bolomys, and the northern grass mouse has recently been transferred from Akodon.
The montane grass mouse is a rodent species from South America. It is found in Argentina, Brazil, Paraguay and Uruguay.
The Serra do Mar grass mouse or Cerrado grass mouse is a rodent species from South America. It is found in Brazil.
The lesser Wilfred's mouse is a species of South American rodents of the family Cricetidae. It was first described by Wilfred H. Osgood under the name Thomasomys pictipes, then into the genus Wilfredomys, and now known as Juliomys pictipes. The lesser Wilfred's mouse is endemic to northeastern Argentina and southeastern Brazil. Its physical appearance ranges from dark brown to light orange coloration and the typical size is small to medium. This species is arboreal, spending most of its time trees and living in the local forests at altitudes from sea level to 2000 m. Currently, this species is listed as Least Concern by the IUCN, but, threats include livestock farming, ranching, and wood harvesting.
Rhipidomys is a genus of rodents in the family Cricetidae, The following 25 species of climbing mouse species are currently recognised:
The Bogotá grass mouse or Bogotá akodont, is a species of rodent in the family Cricetidae. It is found in the Andes eastern and central Colombia and northwestern Venezuela. Alavarado-Serrano and D'Elía (2013) have assigned the species to a new genus, Neomicroxus along with Neomicroxus latebricola.
Akodon boliviensis, also known as the Bolivian grass mouse or Bolivian akodont, is a species of rodent in the family Cricetidae. It is found in the Andes from southeastern Peru through Bolivia into northwestern Argentina.
The Ecuadorian grass mouse is a species of rodent in the family Cricetidae. It is found only in Ecuador.
Abrothrix olivacea, also known as the olive grass mouse or olive akodont, is a species of rodent in the genus Abrothrix of family Cricetidae. It is found from northern Chile into southern Chile and Argentina, including the islands of Tierra del Fuego. It is prone to large swings in population size.
Akodon spegazzinii, also known as Spegazzini's akodont or Spegazzini's grass mouse, is a rodent in the genus Akodon found in northwestern Argentina. It occurs in grassland and forest at 400 to 3,500 m above sea level. After the species was first named in 1897, several other names were given to various populations now included in A. spegazzinii. They are now all recognized as part of a single, widespread and variable species. Akodon spegazzinii is related to Akodon boliviensis and other members of the A. boliviensis species group. It reproduces year-round. Because it is widely distributed and common, Akodon spegazzinii is listed as "least concern" on the IUCN Red List.
Akodon sylvanus, also known as the forest grass mouse or woodland akodont, is a species of rodent in the family Cricetidae. It is found only in a small part of northwestern Argentina.
Reig's montane mouse is a species of rodent in the family Cricetidae. It is found only in Venezuela. It is named after Argentine biologist Osvaldo Reig (1929–1992).
In mammals, ungual tufts are tufts of hairs at the base of claws of the forefeet and hindfeet. Their presence has been used as a character in cladistic studies of the Cricetidae, a large family of rodents.
Bibimys chacoensis is a species of small rodent of the family Cricetidae living in the north-central part of Southern Cone of South America. The common name of this species is Chaco crimson-nosed rat. It is one of the three species currently recognized under the genus Bibimys.
