How are invasive species typically introduced to new environments?

Invasive species are commonly introduced to new environments mainly through mechanisms such as trade, travel, or accidental release. This process often occurs when humans inadvertently transport these species across regions, whether it be through international shipping, the pet trade, or even when they cling to vehicles or goods. For example, a species may escape from a shipping container or be released by an owner who can no longer care for them, allowing them to establish footholds in new ecosystems.

Natural disasters typically do not facilitate the introduction of invasive species; rather, they can displace existing species or alter habitats. Intentional releases for agriculture, while a possible vector for some invasive species, do not encompass the broader range of methods through which most invasives enter new environments. Furthermore, migration of native species involves the movement of species that already belong to the ecosystem, which does not apply to invasive species that are, by definition, non-native and can disrupt local ecosystems. The impact of human activity in introducing invasive species is far more significant and prevalent in ecological studies.