Destroying Ourselves

Brandon Carmichael
April 8th, 2011
On my way back to the United States from my spring break trip to Costa Rica, I noticed a sign at the airport that encouraged people to not bring home exotic pets. This prompt got me to think of all the problems that people have created over the centuries because of improper care or containment of pets. It is unfortunate to say, but there are a surprisingly large number of ecosystems that have introduced species running around because of human intervention, both intentional and unintentional. Invasive species are a problem everywhere; locally we’re fighting an emerald ash borer beetle infestation, in Florida the everglades are swamped with boa constrictors, in our lakes and rivers we have problems with carp and snakeheads and on the other side of the world, in Australia, people have introduced rabbits and cane toads, both of which have swarmed the continent. Wild pigs create a problem all over the world because of the way they dig up the earth and eat nearly everything in sight. To be fair, some species have been introduced purely on accident, but there are many more that have been released on purpose, generally in an effort to get rid of another problem animal.
Pet ownership requires a lot of responsibility and sometimes people simply are not prepared for that responsibility. In the case of boa constrictors, owners are sometimes unprepared for the eventual size of the animal or the costs associated with feeding the continuously growing animal. As a way of shedding this responsibility, some negligent snake owners in Florida decided that simply releasing the animals into the everglades was either the easiest or cheapest way to get rid of the animals. What they didn’t realize was that once the snakes were able to set up a breeding population, they effectively shifted the entire food chain of the region by placing themselves as the top predator. Today the snakes roam the everglades almost without fear, except when they’re young. However, it’s not just carnivores that can throw off an ecosystem; herbivores can wreak just as much havoc, if not more. For instance, in Australia rabbits have been introduced to the grasslands where, naturally, their population levels took off. Without any natural predators and the ability to not only out-compete, but also out-breed any competition, the rabbits started to have a huge effect on the populations of the native marsupial herbivores. Once the people of Australia took notice of this, they decided to try to do something about their rabbit problem by introducing foxes. Unfortunately, this ended up leading to more of a snowball effect because while the foxes did eat the rabbits, they also started going after the slower, less apprehensive marsupials, such as wombats.
A complete lack of knowledge can, of course, lead to terrible outcomes when it comes to introducing a new animal, but a small amount or basic knowledge of something can be even more dangerous. For example, in Australia, farmers who were having trouble with beetles destroying their crops decided to have some cane toads sent over from Hawaii because they knew the cane toads ate most anything smaller than themselves. Regrettably, this plan backfired because it turned out that the toads did not acquire a taste for the beetles and escaped the farmlands in search of food, which they found plenty of. Today cane toad numbers are astronomical because they have no predators that can handle the toxin that they produce. Even though Australia is home to some of the most venomous species of snakes in the world, one attack on a cane toad kills most any would-be predator in Australia. While I have no intention of promoting pesticides, they do seem to be a better alternative to other “natural” solutions we, as humans, have come up with in the past.