The wild horses of today are technically not a native North American species, however, they have become an important part of the ecosystem none the less. Horses were present in the Americas pre-colonial era, but were wiped out by a great extinction 11,000 to 13,000 years ago. The Lakota Indians of South Dakota rode the wild Lakota horses. The Lakota Horse Conservation Foundation claims that strings of Lakota horses living today are decedents of the pre-colonial horses that survived the extinction, but that theory has been proven incorrect. It is believed that the modern horse, or the Equus genus, originated in North America and dispersed to Eurasia, presumably across the Bering land bridge, about 3.4 to 3.9 million years ago and the Lakota…show more content… In 1493, during Columbus’ second voyage to the Americas the Spanish introduced horses to the Virgin Islands. In 1519 horses were reintroduced to the continent in Mexico and Central America, where they migrated to the modern day United States by escaping from farms or through a process called pilfering done by European settlers. Pilfering involved turning large herds of horses out and letting them breed naturally for later use. This process benefited both the horse herds and the settlers, as the settlers did not have to manage horses in captivity and natural selection built strong genetics and characteristics among the horses. These herds of Spanish horses made their way to the United States where Native Americans began to use them. Wild horses soon began to co-exist with native species such as bison and deer. The ecosystem of the American west was perfect for supporting the horses, as it provided plenty of forage, water and open land. It is believed that bison and wild horses are the sole reason for the “sea of grass” in the American…show more content… Like the horse, cattle are not native to the Americas and unlike their cousins, the bison, they have done nothing good for the ecosystem. “Domestic cattle pose a threat to 14% of endangered species and 33% of plant species as they encroach on more land every year.” (Bardroff onegreenplanet.org) The foliage eaten by wild animals and domestic animals is diminishing, and the only solution large cattle farms can come up with is to get rid of the competition. Without wild horses or other species the cattle have more land to graze, which means more money for businesses. Without the crucial replanting process grazing land has to go through in order to stay alive and fertile it will die out and it will not grow