Invasive species compete for the same natural resources such as food and water which the native species also need for survival.
Explanation:
Invasive species upset the stability of the ecosystem because the prey in their new environment does not have the needed defense against them. They also upset the food chain, consume so much, and overpopulate in the new territory thus causing the extinction of the native species.
The introduction of brown tree snakes in Guam disrupted the ecological system as their population increased rapidly because their preys in this new environment lacked the ability to defend themselves against the brown tree snakes. For this reason, more than twelve native birds in the Guam Islands went into extinction. They also consumed the natural resources needed for the survival of the native species.
