STATES CHRONICLE – Researchers from Durham University performed an extensive analysis of invasive species in the world, and identified the top three places where they have established their populations. These hotspots of alien species are the Hawaiian Islands, the North Island in New Zealand, and the Lesser Sunda Islands in Indonesia.
What are invasive species?
Invasive species, also known as alien species, are native to a certain place but, due to human activities, their populations are spread and become established in other regions. They are called invasive since they ‘invade’ these places and don’t populate them naturally.
For the study, published in the journal Nature Ecology & Evolution, researchers analyzed the populations of eight groups of animals on 423 inland regions and 186 islands. Apart from discovering where invasive species are prevalent, they wanted to highlight the importance of taking measures against introducing more alien animals in vulnerable ecosystems.
Islands and coastal regions have the most alien species
Invasive species are present more on islands and near the coasts of mainland regions. The Hawaiian Islands, for instance, represent the top hotspot for such species, and contain alien animals from all the eight groups studied. Among these populations, there are guppy fish, who now spread all over the globe, and feral pigs.
New Zealand is on the second place, where plants represent most of the invasive populations on the islands. In fact, almost half of the plants in New Zealand are alien species. Also, plenty of predatory mammals are invasive, and they threaten native bird species, who did not evolve with a protective mechanism against these species. These mammals include possums, cats, and rats.
From the US, Florida is a place where many alien species have gathered. Burmese pythons which populate the Everglades are one of the main ‘invaders’. They came to Florida originally as pets, but they were released either accidentally or intentionally, and now ended up populating a big part of Florida.
Controlling invasive species and preventing them from spreading to other regions non-native to them is vital, since they threaten the ecosystems they occupy. Native species cannot adapt to alien predators, so they are in danger, thus affecting the balance of the environment.
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