Lock your doors! Shutter the windows! They are on their way and they’re coming to get us.
No, this is not the imminent zombie apocalypse that the social networks have been warning us about for ages. Neither is it an alien invasion from outer space that will steal our planet and replace us with mindless pods.
We are not dealing with science fiction here. The danger, it seems, stems from invasive species which have escaped into our forests, wetlands, rivers, oceans and even the skies above our heads. Whether they have been imported accidentally or intentionally, they pose a threat to the biodiversity of our country, province and even this island we call home.
These alien invasive species may come in the form of plants, mammals, reptiles, amphibians, birds, invertebrates, and even micro-organisms. Instead of bearing ominous monikers like Vlad the Undead or Gork from Klingon, they may carry innocuous names such as Lilly of the Valley, zebra mussel or house finch. Make no mistake, though; once they get a foot, root or fin in the door, they are almost impossible to control.
According to the Salt Spring Island Conservancy, approximately 175 different exotic plants have infiltrated our woods and forests. They may look pretty and may even have some beneficial effects, but they are bullishly aggressive and it’s almost a guarantee that they will not play “nice” when push comes to shove. If left to their own devices, they are sure to choke out the native plant species that have spent eons adapting to our climate and geography. The conservancy advises that these intruders should be removed whenever and wherever they are encountered.
You can draw a comparison between these noxious weeds and your obnoxious, good-for-nothing, freeloading brother-in-law who lands on your doorstep with yet another sad-sack story about how his landlord has evicted him for absolutely no reason and he just needs a place to crash for a few days, max, and you know that months later he will still be couch-surfing in your basement while eating you out of house and home.
Okay, maybe I’m exaggerating. Your invasive plants are much worse than that. Once you let even one in, it will spread like a cancerous growth, sucking up all the nourishment and moisture from the soil while at the same time blocking any light from reaching those native organisms that depend on the sun’s energy to survive. Come to think of it, I have a cousin who is just like that.
Never mind that, though. Let’s take a look instead at how the introduction of an invasive animal can spell disaster for an ecosystem. In the mid-19th century, Hawaii was a major global producer of sugar cane. Unfortunately, rats, themselves invasive aliens who had come ashore from the holds and bilges of sailing vessels over the previous centuries, had multiplied to the point where they were destroying entire cane crops on the plantations. As a result, somebody came up with the brilliant idea to import the mongoose, a small furry mammal native to Africa, Asia and parts of Europe. The plan was for the mongoose to eradicate the rat population and thereby save the sugar cane economy. The Hawaiian brain trust brought in 72 mongooses, bred and raised them, and eventually let them loose to feed on the island rats.
There was one problem, though. Rats are nocturnal creatures who sleep during the day. Mongooses, on the other hand, are active only during the day. Consequently, the two never had the pleasure of making each other’s acquaintance. Instead, the mongoose practically demolished much of the local native species of fauna, including seabirds and nests of turtle eggs. You might say Hawaii was mon-“goosed” by an invasive species.
You may ask why we revere our native species so much while we discriminate against the invasive outsiders. Shouldn’t it be equal opportunity for all and let the best organism win? Why not let Darwinian natural selection decide who sits at the top of the food chain for species?
To answer this conundrum, let’s take a closer look at an insect that has had great difficulty gaining entry to our Canadian land of plenty. This insect, the Asian red-necked longhorn beetle, is a wood-borer that breeds in flowering hardwoods, particularly Asian orchard crops such as plum, peach and apricot trees, themselves non-natives but not on the no-go list. Seeking refuge from the uncertain political turmoil in their home countries, these beetles have been stymied in their attempts to gain entry to our otherwise welcoming land. This unsuccessful beetle invasion has been turned back by border officials declaring that we don’t need foreign tree-killing insect pests when we have more than enough of our own. Plus, we really enjoy our stone fruits! So we pick and choose our enemies. Is it any wonder that, due to our border discriminatory policies, these beetles have developed red necks?
Nobody asked me, but there exists one invasive species that makes all the rest of the unwelcome others come across as specially invited guests of honour who are being hosted at the environmentally friendly VIP lounge wet bar. Can you guess the name of this species? Of course, we refer here to the human being. We are the ones who can take a sublimely unique and fragile ecosystem and transform it, willy-nilly, into a sterile wasteland, just because we can. We have the knowledge and power to drain precious wetlands and flood ecologically diverse grasslands. We pollute the oceans with micro-plastics at the same time as we foul our rivers and freshwater catchment basins with excrement and industrial wastes. In short, we are our own brothers-in-law. We are the ones just looking for a place to crash until our situation takes a turn for the better.
So, if you’re making a list of all the invasive species we should be vigilant and suspicious of, here are a few you should consider:
Marsh plum thistle, knotweed, purple loosestrife, Atlantic salmon, bullfrog and European starling. And at the top of the list: Homo sapiens.