A wild horse (or burro) is classified under United States law as a horse or burro (descendants) that was found on public land in 1971 after the passage of the Wild Free Roaming Horse and Burro Act of 1971. However the term “wild horse” actually brings with it a fierce debate.
The horse we know today, called Equus evolved in North America. The current scientific consensus is that Equus came close to dying out about 10,000 years ago. It is believed that at that time a few migrated into Asia across the Bering land bridge connecting Alaska with Siberia. Consensus currently claims that horses were not on the North American content again until the Spanish brought them back over 500 years ago. It is believed that the horses brought by the Spanish repopulated the North American continent along with animals introduced by settlers.
One of the most fascinating discoveries was that of Yukon horse (Equus lambei). This smaller (about 12 hands) evolved equid populated Alaska, Yukon and Northwest Territories. Yukon horse resembles Preswalskii’s horse.
The origin of the horse is not in debate. But you will often hear a fierce debate using the terms “feral” in a versus argument to “wild.” Feral is a term used to describe a domestic animal turned wild, almost exclusively to a species that is “non-native” to an area. We use the word “wild” almost exclusively to refer to a native species living in a wild state. In the case of “wild horses,” using currently accepted science, the most appropriate technical term would be “reintroduced native species.” A reintroduced native species, living in an environment that evolved concurrently with that species, would create a harmonic wild existence.
The debate rages not because of any debate of origin, it rages because of a debate on how the animals are managed on the land. Those that want the resources utilized by maintaining any wild horse or burro population use the term “feral” to attempt to get the animals removed from public land.
This debate becomes important when you look at the different jurisdictions that manage wild horses. The legal term “wild” is used in the management of horses and burros managed under the Act on Bureau of Land Management Land and also supposedly on Forest Service land. The term “feral” is used in management in Sheldon National Wildlife Refuge, (Fish and Wildlife) for example and the plan is to eradicate horses from the Refuge.