In many areas, a variable mixture of these hybrids and feral pigs of all-domesticated original stock (even environmental, agricultural, hunting, and other regulatory agencies often do not bother distinguishing between them) have become invasive species.

[1] Feral pigs in general are considered to be the most important mammalian pest of Australian agriculture[2] (a difficult title to hold, given the country's long-running invasive rabbit problem).

Because of their increasing numbers (at least 6 million in 2014,[6] having approximately tripled since 1990[5]), in more recent decades they have been hunted more programmatically to reduce their impact as an invasive species; they have become a pest animal responsible for significant agricultural and property damage[6] and environmental harm, especially in the U.S.

[10] They have become problematic even in cooler, forested northern states (and into Canada); a particular conservation problem is that they strip plant life in woodland areas of their berries and other nutrients needed by the native American black bear.

[16] Actual wild boars were introduced in the early 20th century into Uruguay, again for hunting, and have since spread into Brazil, where they have been deemed an invasive species since at least 1994,[17] especially in Rio Grande do Sul, Santa Catarina, and São Paulo.

[19] Unrelated, smaller, and entirely wild suids, known as peccaries or javelinas, range throughout Latin America into the U.S. Southwest, are native to western hemisphere, and are not pest animals, though they compete for resources with hybrid and feral pigs.