A Mustang is a free-roaming feral horse of the North American west that first descended from horses brought to the Americas by the Spanish. Mustangs are often referred to as wild horses, but the more correct term is feral horses.
In 1971, the United States Congress recognized Mustangs as “living symbols of the historic and pioneer spirit of the West, which continue to contribute to the diversity of life forms within the Nation and enrich the lives of the American people.” Today, Mustang herds vary in the degree to which they can be traced to original Iberian horses. Some contain a greater genetic mixture of ranch stock and more recent breed releases, others are relatively unchanged from the original Iberian stock, most strongly represented in the most isolated populations.
Today, the Mustang population is managed and protected by the Bureau of Land Management. Controversy surrounds the sharing of land and resources by the free ranging Mustangs with the livestock of the ranching industry, and also with the methods with which the federal government manages the wild population numbers.
The English word "mustang" comes from the Mexican Spanish word mestengo, derived from Spanish mesteño, meaning "stray" or "feral animal". The Spanish word in turn may possibly originate from the Latin expression animalia mixta (mixed beasts), referring to beasts of uncertain ownership, which were distributed in shepherd councils, known as mestas in medieval Spain. A mestengo was any animal distributed in those councils, and by extension any feral animal.
Horses lived in North America in prehistoric times, but died out at the end of the last ice age around 10-12,000 years ago, possibly due to climate change or the impact of newly-arrived human hunters. Horses returned to the Americas by the Conquistadors, beginning when Columbus imported horses from Spain to the West Indies on his second voyage in 1493. They returned to the mainland with the arrival of Cortés in 1519.
The first Mustangs descended from Iberian horses brought to Mexico and Florida. Most of these horses were of Andalusian, Arabian and Barb ancestry. Some of these horses escaped or were stolen by Native Americans, and rapidly spread throughout western North America.
Native Americans quickly adopted the horse as a primary means of transportation. Interestingly, in light of the horse's prehistoric existence in the Americas, many Indian myths and stories about the arrival of horses claimed that "the grass remembered" them. Horses replaced the dog as a travois puller and greatly improved success in battles, trade, and hunts, particularly buffalo hunts.
Starting in the colonial era and continuing with the westward expansion of the 1800s, horses belonging to explorers, traders and settlers that escaped or were purposely released joined the gene pool of Spanish-descended herds. It was also common practice for western ranchers to release their horses to locate forage for themselves in the winter and then recapture them, as well as any additional Mustangs, in the spring. Some ranchers also attempted to "improve" wild herds by shooting the dominant stallions and replacing them with pedigreed animals.
By 1900 North America had an estimated two million free-roaming horses. Since 1900, the Mustang population has been reduced drastically. Mustangs were viewed as a resource that could be captured and used or sold (especially for military use) or slaughtered for food, especially pet food. The controversial practice of mustanging was dramatized in the John Huston film The Misfits, and the abuses linked to certain capture methods, including hunting from airplanes and poisoning, led to the first federal wild free-roaming horse protection law in 1959. Protection was increased further by the Wild Free-Roaming Horse and Burro Act of 1971.
Today, free-roaming horses are protected under United States law, but have disappeared from several states where there were once established populations. A few hundred free-roaming horses survive in Alberta and British Columbia. The BLM considers 27,000 individuals a manageable number, but the feral Mustang population currently exceeds 33,000. More than half of all Mustangs in North America are found in Nevada (which features the horses on its State Quarter in commemoration of this), with other significant populations in Montana, Wyoming and Oregon. Another 30,000 horses are in holding facilities.
In some modern mustang herds there is clear evidence of other domesticated horse breeds having become intermixed with feral herds. Some herds show the signs of the introduction of Thoroughbred or other light racehorse-types into herds, a process that also led in part to the creation of the American Quarter Horse. Other herds show signs of the intermixing of heavy draft horse breeds turned loose in an attempt to create work horses. Other, more isolated herds, retain a strong influence of original Spanish stock.
Some breeders of domestic horses consider the Mustang herds of the west to be inbred and of inferior quality. However, supporters of the Mustang argue that the animals are merely small due to their harsh living conditions and that natural selection has eliminated many traits that lead to weakness or inferiority. Some mustang supporters also maintain that some "inbreeding" actually concentrates the traits of hardiness and durability, making the mustang a valuable genetic resource. Regardless of these debates, the Mustang of the modern west has several different breeding populations today which are genetically isolated from one another and thus have distinct traits traceable to particular herds. These herds vary in the degree to which they can be traced to original Iberian horses. Some contain a greater genetic mixture of ranch stock and more recent breed releases, others are relatively unchanged from the original Iberian stock.
Controversy surrounds the presence of feral Mustang herds. Supporters argue that Mustangs are part of the natural heritage of the American West, whose history predates modern land use practices, and thus the animals have an inherent right of inhabitation. However, other people remain vehemently opposed to their presence, arguing that the animals degrade rangeland and compete with livestock and wild species for forage.
The debate as to what degree Mustangs and cattle compete for forage is multifaceted. One group of opponents, primarily cattle and sheep ranchers and those who depend on the livestock industry, argue essentially that feral horses degrade rangeland and compete with private livestock for public land forage. The environmentalist community is split over the position of the Mustang within the North American ecosystem. This debate centers on the potential classification of Mustangs as either an introduced species such as cattle, or as a reintroduced native species due to the prehistoric presence of horses in North America, albeit with a gap of thousands of years between their extinction and reintroduction from European stock.
Researchers note that most current Mustang herds live in arid areas which cattle cannot fully utilize due to the lack of water sources. Horses are better adapted by evolution to such climates.; they may range nine times as far from water sources as cattle, traveling as much as 50 miles a day. This allows them to utilize areas not grazed by cattle. In addition, horses are "hindgut fermenters," meaning that they digest nutrients by means of the cecum rather than by a multi-chambered stomach. In practical effect, horses can obtain adequate nutrition from poorer forage than can cattle, surviving in areas where cattle will starve.
The Bureau of Land Management (BLM) is tasked with protecting, managing, and controlling wild horses and burros under the authority of the 1971 Wild Free-Roaming Horses and Burros Act to ensure that healthy herds thrive on healthy rangelands and as multiple-use mission under the 1976 Federal Land Policy and Management Act. Under the 1971 Act, shooting or poisoning Mustangs in the wild is illegal, and doing so can be prosecuted as a criminal felony.
Healthy adult Mustangs have few natural predators aside from mountain lions, and their herd sizes can multiply rapidly. To maintain population balance, (or, some argue, to make room for cattle) one of the BLM’s key responsibilities under the 1971 law is to determine an appropriate management level (AML) of wild horses and burros in areas of public rangelands dedicated specifically for them. Control of the population to within AML is achieved through a capture program.
Most horses that are captured are offered for adoption to individuals or groups willing and able to provide humane, long-term care after payment of an adoption fee that ranges from $25 to $125. In order to prevent the later sale of mustangs as horse meat, adopted mustangs are still protected under the Act, and cannot be sold in the first year except when certain very specific criteria are met.
Because there is a much larger pool of captured horses than of prospective adoptive owners, in January 2005, a controversial amendment was attached to an appropriation bill before the United States Congress by former Senator Conrad Burns, dubbed the "Burns rider. This modified the adoption program to allow the sale (with the result usually being slaughter) of captured horses that are "more than 10 years of age", or that were "offered unsuccessfully for adoption at least three times. In the 110th United States Congress, legislation was introduced to have the rider repealed and the original language restored. The matter passed the House of Representatives and as of mid-2008 still awaits action in the Senate. At present, with about 30,000 Mustangs in holding facilities, the BLM has, for the first time in public, considered euthanasia as a possible solution to overpopulation.