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.
A cotton rat is any member of the rodent genus Sigmodon. Their name derives from their damaging effects on cotton as well as other plantation crops, such as sugarcane, corn, peanut and rice. Cotton rats have small ears and dark coats, and are found in North and South America. Members of this genus are distributed in the Southwestern United States, Mexico, Central America, and South American countries of: Venezuela, Ecuador, Colombia, Peru, Brazil, Guyana, and Suriname. Many of the species are found in Mexico.
The hispid cotton rat is a rodent species long thought to occur in parts of South America, Central America, and southern North America. However, recent taxonomic revisions, based on mitochondrial DNA sequence data, have split this widely distributed species into three separate species. The distribution of S. hispidus ranges from Arizona in the west to Virginia to the east and from the Platte River in Nebraska in the north to, likely, the Rio Grande in the south, where it meets the northern edge of the distribution of S. toltecus. Adult size is total length 202–340 mm (8.0–13.4 in); tail 87–122 mm (3.4–4.8 in), frequently broken or stubbed; hind foot 29–35 mm (1.1–1.4 in); ear 16–20 mm (0.63–0.79 in); mass 50–250 g (1.8–8.8 oz). They have been used as laboratory animals.
The American gray flycatcher, or American grey flycatcher, or just gray flycatcher as it is known in North America, is a small, insectivorous passerine in the tyrant flycatcher family. It is common in the arid regions of western North America, especially the Great Basin. From sagebrush steppes to pinyon-juniper woodlands and ponderosa pine forests, this flycatcher forages for insects from shrubs or low tree branches.
Ord's kangaroo rat is a kangaroo rat native to western North America, specifically the Great Plains and the Great Basin, with its range extending from extreme southern Canada to central Mexico.
The white-throated woodrat is a species of rodent in the family Cricetidae. It is found from central Mexico north to Utah and Colorado in the United States. It is primarily a western species in the United States, extending from central Texas west to southeastern California. Populations east of the Rio Grande in New Mexico and Trans-Pecos Texas, previously considered to be variants of the white-throated woodrat, have since 1988 been assigned to the white-toothed woodrat.
Stephen's woodrat is a species of rodent in the family Cricetidae found in Arizona, New Mexico and Utah in the United States.
The brush mouse is a species of rodent in the family Cricetidae. It is found in mountainous areas of Mexico and the western United States at altitudes over 2,000 m (6,600 ft).
Allen's cotton rat is a species of rodent in the family Cricetidae. It is endemic to western Mexico, where its distribution extends from Sinaloa to Oaxaca. The formerly recognized S. planifrons and S. vulcani are now considered conspecific with S. alleni by the IUCN.
The Arizona cotton rat or Colorado River cotton rat is a species of rodent in the family Cricetidae. It is found in Mexico and the United States.
The tawny-bellied cotton rat is a species of rodent in the family Cricetidae. It is found in Mexico and in the US states of Arizona and New Mexico.
The Jaliscan cotton rat or Mexican cotton rat is a species of rodent in the family Cricetidae. It is found only in Mexico. They commonly have brown fur with white fur on the belly. They are ground-dwelling and prefer open habitats.
The southern pocket gopher is a species of rodent in the family Geomyidae. It is found in Mexico and the United States, usually in high altitude grassland and shrubland. It feeds on plant material and has an extensive burrow above which is a large heap of earth on the surface of the ground.
A pack rat or packrat, also called a woodrat or trade rat, are any species in the North and Central American rodent genus Neotoma. Pack rats have a rat-like appearance, with long tails, large ears, and large, black eyes. Pack rats are noticeably larger than deer mice, harvest mice, and grasshopper mice, and are usually somewhat larger than cotton rats.
Pinyon–juniper woodland, also spelled piñon–juniper woodland, is a biome found at higher elevations near deserts in the Western United States, characterized by being an open forest dominated by low, bushy, evergreen junipers, pinyon pines, and their associates which vary from region to region. The woodland's density and crown height varies dramatically depending on a variety of factors, with mature trees ranging in height from as low as 2 meters up to 15 meters. At lower elevations, junipers often predominate and trees are spaced widely, bordering on and mingling with grassland or shrubland. As elevation increases, pinyon pines become common and trees grow closer, forming denser canopies. Historically, pinyon-juniper woodland has provided a vital source of fuel and food for peoples of the American Southwest.
