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10 animals we’ve turned into invasive species

When it comes to the environment , too often humans have the bad habit of disrupting, and not for the better. As individuals, of course there is everything, but if we focus on excesses, the human species is a real problem for this planet.

As it is, the species suffer us. Because of us, many of them are against the ropes, on the way to extinction or directly extinct and, on the other hand, the opposite occurs: an induced proliferation as a consequence of imbalances of the ecosystem caused by us.

It is, in effect, their introduction into new habitats out of unconsciousness or for utilitarian purposes. The examples are innumerable, but they all have in common the creation of a problem in which, applied exterminating measures, it is the animals that end up losing. In short, those known as “invasive species” end up being doubly victims.

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  1. Invasive Species: The Neverending Story
  2. 10 invasive species
  3. Parrots
  4. Gray squirrel
  5. Plasmodium
  6. Wild pigs
  7. The Javanese mongoose
  8. Brown tree snake
  9. Burmese pythons in the Everglades
  10. Florida turtle
  11. La Gambusias
  12. Perca del Nile

Invasive Species: The Neverending Story

Since the mists of time, walking from here to there, nomadically first, and then through trade and migration, have caused important changes in ecosystems. And invasive species have been one of the main victims, in addition to the native ones, which are sometimes defenseless against them.

Flora and fauna introduced by humans are here and there, throughout history, but especially today, it has caused serious problems of ecological balance , since the presence of invasive species pose a significant threat to it.

In addition to hunting and the destruction of the environment, therefore, human action also threatens ecosystems with the introduction of foreign species.

It is a thorny issue that is the focus of the International Union for Conservation of Nature (IUCN). Through its Species Survival Commission, it has compiled a list of the most harmful invasive alien species in the world.

10 invasive species

In this post we focus on fauna . Next, we will see a random selection of a dozen animals whose presence in ecosystems that are alien to them causes problems. The casuistry is very varied, but the essence of the problem is repeated.

It goes without saying that when policies of extermination are carried out, their right to life is not taken into consideration at all. After being classified as pests, their captures are usually given free rein.


Parrots arrived in Spain as exotic pets in the 70s and since then those that escaped and were released voluntarily began to reproduce. They are currently in the thousands. Above all, they belong to the species of Argentine parrot (Myiopsitta monachus) and Kramer’s parrot (Psittacula krameri)

Gray squirrel

Gray squirrels are reducing the range of red squirrels in the UK, with red squirrels being indigenous and those considered invasive. Their introduction was made by humans, who kept them as pets, coming from the United States.


Avian malaria was spread through exotic birds brought to Hawaii by settlers. Its expansion occurred through a mosquito, the Culex quinquefasciatus, which arrived in 1826 by sea, specifically in the water barrels of a boat .

Avian Malaria, together with this vector, led to the extinction of numerous native bird species that lacked resistance, and continues to do so in different areas of the planet. The avian malaria, for example, is also responsible for infections of species of birds in Peru.

Wild pigs

Feral pigs were originally domestic animals that, either by escaping or releasing them, thrived in their new environment and ended up becoming part of the environment. The Sus scrofa species is part of the list that includes the 100 most harmful invasive alien species in the world, prepared by The Global Invasive Species Database, based on information from the IUCN.

The Javanese mongoose

The Javanese mongoose (Herpestes javanicus) hails from Iran, India, the Malay Peninsula, and Myanmar, and was introduced in the late 19th century to control rats. Its irruption in the ecosystems of Mauritius, the West Indies and Hawaii became a great problem, since it caused the extinction of different species.

Brown tree snake

It is a species indigenous to Australia, Papua New Guinea, the Solomon Islands and Indonesia. He is believed to have arrived on Guam, an island in the Western Pacific, as a stowaway on a military plane. It was in the middle of the last century, and by the 70s it had expanded. Its danger lies, above all, in constituting a threat to the diversity of this and other islands with a tropical climate.

Burmese pythons in the Everglades

Overpopulation of snakes pythons Burmese in Everglades National Park is a problem that has gone around the world. Reducing the presence of invasive reptiles, pets or descendants of pets, does not end the environmental drama that they pose.

Florida turtle

Also known as the Florida terrapin , they are one of the most popular pets that could be found in pet stores a few years ago. Trachemys scripta is now prohibited from being introduced throughout Europe to avoid uncontrolled release , as they cause damage to ecosystems.

La Gambusias

They are tiny little fish, from the fresh waters of the eastern and southern United States. The problem was created by humans with their intentional introduction to control mosquitoes. Although they were effective, indigenous predators were no less so, expert voices say. They began to be introduced at the beginning of the last century and continue to be done.

Perca del Nile

The introduction of the Nile perch (Lates niloticus) in Lake Victoria in 1954 to increase the fishery resources, depleted by overfishing, was not a good idea. On the contrary, since their arrival the extinctions of native fish multiplied and chain reactions took place that were disastrous for the ecosystem and for the local subsistence economy.

On the one hand, deforestation skyrocketed to dry up the catches of this perch. On the other hand, the excess of organic residues caused a plague of algae that reduced the oxygen in the water, triggering the death of the fish.

If you want to read more articles similar to 10 animals that we have turned into invasive species , we recommend that you enter our Wild Animals category .

Maria Anderson

Hello, I am a blogger specialized in environmental, health and scientific dissemination issues in general. The best way to define myself as a blogger is by reading my texts, so I encourage you to do so. Above all, if you are interested in staying up to date and reflecting on these issues, both on a practical and informative level.

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