Though the term alien might conjure ideas of bulbous headed beings coming down from weird, floating spaceships, the term means something different for biologists. For them, an alien species is one that has been introduced to an area where they do not exist naturally. In some cases, alien species can start taking over that area, slowly becoming an invasive species.
A group of researchers from Durham university have created the first full scale analysis of alien fauna and flora to create a hotspot map of areas on the planet have the most alien species. Their studies have shown that areas of high population density of humans tend to have the largest number of alien species, as they bring these foreign animals into new landscapes with them, and stray variants then find themselves in the wild. Islands in particular have a high alien species richness, with Hawaii and New Zealand having very broad ranges.
Many things determine the likelihood of an alien species managing to thrive in their new environment, with factors like weather, geography, native species and their threat, and human interaction all being important. Students who are hoping to apply for Biology or Natural Sciences should study how each of these things would have an effect on animals, and they should also look into particularly aggressive invasive species as a good examples for possible interviews.