How can invasive species outcompete native species for food and habitat?

Invasive species often outcompete native organisms by possessing built-in competitive advantages that allow them to thrive in new environments where natural predators are absent. When these species colonize a new area, they may aggressively monopolize essential resources, effectively preventing native species from accessing necessary food, living space, or other vital requirements.1

This process is often explained by the principle of competitive exclusion, which states that when two species compete for the same ecological niche, one will typically survive while the other is displaced or faces localized extinction.12

Invasive species may also disrupt ecosystems by acting as disease vectors, spreading parasites and pathogens that further weaken native populations. While some "weedy" or r-selected species are specially adapted to colonize disturbed environments through high reproductive output and rapid dispersal, they are often eventually outcompeted by hardier species in stable climax communities. However, in the absence of such natural checks, invasive species can permanently alter biodiversity and replace native ecosystems.13