Who would not want to protect the presumed “native species” from these invaders?
Two aspects of such invasions should be made explicit. First, such encroachments are usually not anthropogenic. Second, such incursions are inevitable.
Species were invading each other’s habitats long before humans had the ability, by means of long-range travel, to accidentally or knowingly introduce alien plants and animals into new domains. Insects clinging to driftwood can cross oceans. Fish eggs on the feet of waterfowl can travel from one inland lake to another.
If a species is originally confined to one habitat, then it is certain that it will one day either go extinct, or it will find its way into another habitat — and thereby become an invasive species. A microbe or a plant originally found in Africa will, sooner or later, arrive in Asia, Europe, or the Americas — or it will become extinct.
The species which now seem to be the native species in a given domain, whether it’s a North American grassland or an Asian rainforest, were once invaders. There was a time when those species were not to be found in that place. The arrival of those flora and fauna into the current location had nothing to do with humans.
In a tendency analogous to entropy, all the species eventually swirl in slow-motion around the globe. Every species is an invasive species, and by the same token, every species is a native species.
It is also inevitable that the vast majority of these species will eventually become extinct, and this again will not be an anthropogenic process.
Any effort to stop or slow invasive species may be aesthetically productive, but the judgment about which species has the right to be in a particular habitat is at best unclear, and the efforts to stop such invasions will ultimately fail.
