Introduce one species to get rid of another—seems simple enough, right? As humans, we’ve managed to introduce non-native species everywhere, often with the goal of eradicating a pest or controlling another animal’s population. Ironically, many of these non-native organisms then take over the environment, producing enough dramatic fodder for B-list movies such as The Deadly Bees (Africanized killer bees, anyone?) and invading the habitats of many valuable native or endangered creatures. Here are some of the worst offenders and evidence of their damage, which will undoubtedly surprise and shock you.
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The kudzu plant, native to Japan, seems innocent enough. It was introduced to the U.S. in the 1870s as a fast-growing vine that could help prevent soil erosion. But “fast-growing” was right, because the plant is now considered a serious pest in the eastern states. In fact, it’s nicknamed “the vine that ate the South.” The powerful plant is known to have a detrimental effect on forestry plantations and for crowding out native plants. The vine, which can grow from 30 to 100 feet, can even break or uproot entire trees through the sheer force of its weight.
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The European Rabbit
The often-used phrase “breeding like rabbits” has a solid historical background. Originally from Spain and Portugal, the cuddly, furry creature you know as the common rabbit is everywhere. When Australian farmer Thomas Austin released 24 rabbits on his land in 1859, the rabbit population subsequently exploded, significantly affecting Australia’s native species and even the soil. The Australian government introduced multiple viruses in an effort to curb the population of these little critters, who have cost countries across the world millions in damage.
Originally from Russia, these mussels came to North America by way of a transatlantic freighter and have spread through the Great Lakes in Michigan and Canada. Seemingly innocuous, these mussels multiply quickly, clogging pipes and competing with native species. They also filter water quickly, eliminating phytoplankton and much of the food supply for native species.
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Small Asian Mongoose
The small Asian mongoose (or Indian mongoose), brought over to Hawaii by a sugar cane planter in the 1880s, was supposed to control rats in cane fields. Instead of eating rats, these predators chose to prey on native bird species and endangered sea turtles. Mongooses breed often, and females often produce 2-3 litters of a few pups every year. These invaders, who also happen to be a big problem in Japan, cost an estimated $50 million in damages to the Hawaiian islands and Puerto Rico every year.
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Africanized Honey Bees (‘Killer’ Bees)
A well-publicized phenomenon, killer buzzing bees automatically come to mind when the phrase “invasive species” is uttered. In 1957, 26 Tanzanian queen bees were released accidentally and mated with their European counterparts, producing these Africanized honey bees. These buzzing threats starting traveling north from their native Brazil in the 1970s, and now have been found in various states across the U.S. These creatures are not your happy bumblebee though: quick to attack (which means more stings), aggressive and highly protective of their hives — they will even chase a person for a quarter-mile or more to defend it. Their strength in outcompeting and displacing other pollinators has created problems for the honey industry, as well as for the general pollination of orchards and crops.
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The YouTube videos say it all — this fish is a force to be reckoned with. Fishermen have captured footage of the carp jumping 10 feet in the air and landing on the deck of boats: entertaining, if it weren’t so alarming. Two species of Asian carp — the bighead and the silver carp — were imported into the southern U.S. around the 1970s and then escaped the aquaculture facilities they were meant for. They now dominate the Mississippi and Illinois rivers. Black and grass carp are also abundant in the U.S. now, contributing to the massive consumption of plankton and eliminating the food supply for native fish species. To top it off, these invasive swimmers lay hundreds of thousands of eggs at a time, and do so multiple times a year. As a result, the Asian carp’s massive appetite and huge population have produced a noticeable imbalance in the ecosystem.
In 1890, a drug manufacturer named Eugene Schieffelin walked to Central Park and released 60 European starlings he had just received. As the story goes, Schieffelin was a big fan of Shakespeare, and wanted to bring all of the birds mentioned by the Bard to New York City. He added another 40 of the birds the year after, and now the United States has an estimated 200 million of these noisy, aggressive birds. Unfortunately his romantic idea didn’t pan out, as these invaders push out native species, disrupt airplanes, and cause millions in agricultural losses every year. The U.S. government has made an effort to eradicate the resilient pests, from poisons to spray detergents to broadcasting starling distress calls.
(Photo: Yannis Behrakis/Reuters)
The snakehead fish looks like something out of a marine nightmare. With sharp, shark-like teeth and bulbous yellow eyes, the snakehead is what you would hope to never encounter in the water. Originally released from fish markets and by aquarium owners, these fish have been established in the Potomac River and ponds across the U.S. They are hugely concerning because they are “top-level predators” — in other words, snakeheads have no natural enemies, making it easy to kill off entire populations of native fish. Furthermore, these fish can breathe air: they can survive up to four days on land as they look for new bodies of water. To say the least, this fish is nicknamed “Fishzilla” by National Geographic for good reason.
(Photo: Luis D'Orey/Reuters)
The cane toad, the focus of a Participant Media film, is the epitome of an introduced species gone awry. Native to Central America, cane toads were brought to Hawaii in the 1930s to help control sugar cane beetles and other bugs. While their beetle-killing skills failed, cane toads instead took over North America and Australia, where these creatures number in the millions. These vicious toads possess poisonous toxins that usually kill any potential predators, making them an intimidating threat to native species. With an unfortunately big appetite, these invaders steal food from native species and remain a major threat to the ecosystem.
(Photo: David Gray/Reuters)
These 20-foot pythons, a popular pet in the U.S., are often released into the wild when owners cannot handle taking care of them. As a result, these massive intimidating snakes are tearing up Everglades National Park in Florida, chomping on alligators (you read that right) and endangered species. With few predators, these snakes are an intimidating threat to animals in the Everglades and other regions, such as the Florida Keys. These snakes also pose a potential problem to motorists and owners; pythons often stretch themselves across roads and the captive pets have killed their human owners on some occasions. Above, a dead python was found devouring an alligator in the Everglades.