Mustang in the context of Wild horse

The game drive system is a hunting strategy in which game are herded into confined or dangerous places where they can be more easily killed. It can also be used for animal capture as well as for hunting, such as for capturing mustangs. The use of the strategy dates back into prehistory. Once a site is identified or manipulated to be used as a game drive site, it may be repeatedly used over many years. Examples include buffalo jumps and desert kites.

Przewalski's horse (Equus ferus przewalskii or Equus przewalskii), also called the takhi, Mongolian wild horse or Dzungarian horse, is a rare and endangered wild horse originally native to the steppes of Central Asia. It is named after the Russian geographer and explorer Nikolay Przhevalsky. Once extinct in the wild, since the 1990s it has been reintroduced to its native habitat in Mongolia in the Hustai National Park, Takhin Tal Nature Reserve, Khomiin Tal, and several other locales in Central Asia and Eastern Europe.

Several genetic characteristics of Przewalski's horse differ from those seen in modern domestic horses, indicating neither is an ancestor of the other. For example, Przewalski's horse has 33 chromosome pairs, compared to 32 for the domestic horse. Their ancestral lineages split from a common ancestor between 160,000 and 38,000 years ago, long before the domestication of the horse. Przewalski's horse was long considered the only remaining truly wild horse, in contrast with the American mustang and the Australian brumby, which are instead feral horses descended from domesticated animals. That status was called into question when domestic horses of the 5,000-year-old Botai culture of Central Asia were found to be more closely related to Przewalski's horses than to E. f. caballus. The study raised the possibility that modern Przewalski's horses could be the feral descendants of the domestic Botai horses. However, it remains possible that both the Botai horses and the modern Przewalski's horses descend separately from the same ancient wild Przewalski's horse population. Its taxonomic position is still debated, with some taxonomists treating Przewalski's horse as a species, E. przewalskii, others as a subspecies of wild horse (E. ferus przewalskii) or a variety of the domesticated horse (E. ferus caballus).

This list of North American deserts identifies areas of the continent that receive less than 10 in (250 mm) annual precipitation. The "North American Desert" is also the term for a large U.S. Level 1 ecoregion (EPA) of the North American Cordillera, in the Deserts and xeric shrublands biome (WWF). The continent's deserts are largely between the Rocky Mountains and Sierra Madre Oriental on the east, and the rain shadow–creating Cascades, Sierra Nevada, Transverse, and Peninsular Ranges on the west. The North American xeric region of over 95,751 sq mi (247,990 km) includes three major deserts, numerous smaller deserts, and large non-desert arid regions in the Western United States and in northeastern, central, and northwestern Mexico.