Most of the time invasive species become that way by accident. From ash borers to zebra mussels, a lot of critters stow away on ships and end up where they are really damaging. Some species are different, critters released for apparently practical purposes (population control of another invasive species, for example) that did a lot more damage than anticipated like cane toads in Australia.
Then there are the most absurdly frivolous and bizarre reasons to introduce a species to a new environment – such as an homage to literature.
The Common Starling (Sturnus vulgaris) is a small species of songbird native to Europe. It’s not domesticated, not particularly charismatic, and not an economically useful animal. So why was it brought to North America where it started running a muck?
In 1871, a group called the American Acclimatization Society was founded. Due to the cultural idea that Europe was the best and most civilized part of the world, people wanted to make the rest of the world a bit more like Europe. They really had no clue that this was a bad idea, ecologically speaking. In 1877 AAS chairman Eugene Schieffelin embarked on what is one of the most infamous introduction programs of all time.
Schieffelin was a fan of Shakespeare’s works, so the AAS decided to introduce every bird mentioned by Shakespeare in his plays to North America. Now most of these (nightingales, chaffinches, etc.) didn’t transplant at all, and the new populations died out. A few, like pelicans, already had native populations. Starlings did well, absurdly well – flocks a million birds strong well.
It’s amazing how much humans can change bird (or any organism for that matter) populations. Although starlings are now in the US thanks to human intervention, passenger pigeons which once numbered in the billions are extinct due to our appetites. We are one of the most influential/destructive organisms in Earth’s history, and our introduction of starlings to America was one of the more interesting chapters.
– Mazie O’Connor