An ecological island is not necessarily an island surrounded by water, but is an area of land, isolated by natural or artificial means from the surrounding land, where a natural micro-habitat exists amidst a larger differing ecosystem. Also, in artificial ecological islands (also known as mainland islands): * all non-native species (at least predator species) have been eradicated, * native species are reintroduced and nurtured, and * the natural or artificial border is maintained to prevent reintroduction of non-native species.