How does the introduction of invasive species, such as the brown tree snake, upset the stability of an ecosystem?

Invasive species are alien species that proliferate uncontrollably, threatening the balance of an ecosystem. We define as exotic species those that are outside their usual place.

Invasive species did not live in that area, so they usually have no predators. The lack of natural enemies causes these species to reproduce uncontrollably, increasing the size of the population. The increase in exotic population directly affects the ecosystem.

Invasive species usually have large populations, which end up getting more resources than smaller populations. This makes these species stand out over native species when it comes to competition for resources, undermining local balance. We must not forget that the invasive species often feeds on native organisms and may even cause local extinction of a species.

In addition to increased competition and predation, many invasive species are responsible for spreading disease and pests. All these factors cause invasive species to cause marked reductions in populations and considerable habitat degradation. For this reason, they are considered one of the greatest current threats to the environment.

Invasive species may occur entirely naturally, but the most common is the introduction of new species by humans. As man spreads around the planet, more species are moved from one area to another, either accidentally or purposefully. The introduction of new species into an area may be favored by high migration rates, colonization of new areas and increased agriculture and livestock, for example.