2020 has been rife with all manner of natural disasters from the increased frequency of hurricanes to the devastating wildfires that have rocked both Australia and the western portion of the United States. One disaster that got some sensationalized press but was largely neutralized was the infamous “Murder Hornets.” It shined a brief but eye-opening light on invasive species. The murder hornets are only the most visible in a long strain of devastating environmental agitators.
The history of invasive species is a topic that most people are either not aware of or it doesn’t affect their daily lives enough for them to care about. The only reason the murder hornets, otherwise known as the Asian giant hornet, garnered so much attention because of its place in the long string of disasters even though the murder hornets were largely taken care of. That being said, the fuss about the murder hornets was completely justified. The nature of an invasive species is that it has the potential to survive and thrive in a new environment. The Asian giant hornet native to Japan is entirely under control there both because of the habitat and because of other animals in its environment. The forests are so dense that they have no need to spread out and the bees they remain in conflict with there have adapted to combat them. The bees in the state of Washington have no such defenses. That’s why the murder hornets were so dangerous. They could have been devastating to the honeybee population.
The issue of invasive species in North America began with the Spanish inadvertently bringing over water lettuce on ships in the 1500s. Water lettuce can block oxygen circulation in water and kill fish. Feral pigs were also introduced by the Spanish when they brought them as livestock. Pigs are extremely adaptable and can survive in a multitude of environments. The threat of feral pigs, sometimes called “feral hogs,” is largely negligible in the modern era, however. A large portion of truly damaging invasive species was brought over in the colonial period when the public at large was less science-minded.
However, the most common invasive species that nearly everyone has firsthand knowledge of is house cats, house cats let loose specifically. According to National Geographic, domestic cats kill approximately four billion birds and anywhere from six to 22 billion mammals every year. Obviously, no one thinks 600 million cats need to be systematically euthanized, but something must be done to preserve our own biodiversity. Steps we can take deal with adopting cats and keeping them inside. There’s nothing wrong with letting your cats play around outside but they should be treated far more similarly to indoor dogs.
So why do invasive species matter to everyone? Primarily, invasive species can affect our water supply. As mentioned, the Spanish brought over water lettuce. Water lettuce can drastically affect oxygen levels, which in turn can affect fish, but also other organisms that live in our water supply that help to filter out pollutants. They can also affect the natural resources we harvest.
A habitat is only as healthy as its wildlife and animals that don’t belong can end harming everyone, including us.