What is the worst invasive species ever?



  1. 0 Votes

    These five species represent five different examples of where and how overly invasive species can restructure an entire ecosystem and out compete native species for vital resources. They might not be the exact top five, but are excellent examples of invasive species hard at work.

    Number One: Rats

    Rats are found just about anywhere and everywhere in the world. There are dozens of different rat species in the world and each one has evolved an amazing ability to adapt to nearly any condition it may find itself in. One such example of such rodent dominance comes from Alaska’s Rat Island in the Aleutian Island Chain. This small island has been home to a bustling community of Norway Rats due to the destruction of a Japanese ship of its coast in 1780. The US Fish and Wildlife service recently undertook a series of eradication attempts to remove the rats from the island which had choked the island of nearly all its indigenous creatures for more than 200 years. The plans were deemed a success as in 2009, the island was finally declared rat free. Their strategy was probably extremely effective as it was modeled after a plan that also successfully removed another invasive species, the Red Fox from the same island chain.

    Number Two: Cane Toad

    Isolated islands tend to suffer at the hands of invasive species more than larger land masses; nearly all of had to deal with the dreaded cane toad. Known formally as Bufo marinus, these amphibians native to Central and South America have made their way to nearly every island in the Pacific and Caribbean. The toads can be especially invasive as the breed quick and often with fertile females laying thousands of eggs at once. They were once commonly introduced to islands as a form of organic pest control; however their insatiable appetites allowed them to take over and they are now considered a pest. Cane toads usually grow to be between four and six inches long, however specimens have been found measuring several pounds and more than a foot in length.

    Number Three: Rabbit

    Its no surprise that just like its cousin the rat, the rabbit is also an excellent survivor in a range of different conditions. There are many species of rabbit, some more invasive than others, but each can take its own particular toll on the ecosystem. Australia was first introduced to the European Rabbit ion 1859 when 24 rabbits were released on a farm to see if they could survive. They not only survived, but were so efficient that within four decades, the animal has driven the entire continents native grasses to nearly full exhaustion and had killed many native species through simple out-competition. In less than a century, the first 24 rabbits had multiplied to 600 million. Australian efforts in the 1950s to correct the problem were able to reduce their numbers to 100 million; however they remain a problem still today for many Australian lands.

    Number 4: Kudzu

    Kudzu is known by many different names. The Foot-a-night-vines, mile-a-minute-vine, the vine that ate the South, etc. and all of them allude to just how invasive this plant can be. Introduced to the Americas from China and Japan in 1876, the plant has spread from Philadelphia, all the way down to Florida and as far West as Texas and Oklahoma. Best estimates believe this weedy vine covers nearly 7,700–12,000 sq miles of land in the Southern United States and demands nearly $500 million a year in damages to croplands and infestation control.

    Number 5: Snakehead

    This is one of the most interesting invasive species to me, the Northern Snakehead. These huge fish, native to Russia, Korea and China can grow to be between a 3 and 4.5 feet long and weight up to fifteen pounds and are very aggressive. They have rows of sharp teeth and are extremely quick and agile hunters, easily adapting to the fertile waterways of the Eastern United States including the Potomac River. Here, populations of Snakeheads appear to be breeding and thriving, easily overtaking the native species. These ferocious predators can not only easily take over entire river systems, but they can also crawl across land for extended periods of time (sometimes up to four days!) in search of new body of water, making even the most isolated ponds and streams at risk for being colonized by the snakehead.









  2. 0 Votes

    It is hard to pin one invasive species as the worst.  There are many that cause numerous problems.  Zebra Mussels are one that is particularly damaging.  They have helped water quality but with no natural pradators they have outcompeted many natural freshwater species and have diverted a lot of energy from the food web. 

  3. 0 Votes

    I think the species that comes first, naturally, is homo sapiens. Humans will live anywhere, control their environment, and have no predators. Humans do not adapt to their environment, they change it.

  4. 0 Votes

    I’m from Ohio, and I know two things that really have caused problems are 

    1.) The Emerald Ash Borer.  No joke, we litterally have been cutting down every ash tree in the midwest area right now to prevent these from spreading. They burrow into trees and cuase them to rot and die extremely quickly.

    2.) The Asian Carp.  this threat was so large that the army had to set up barriers to make sure that these didn’t get into the great lakes after they caused massive problems in the Mississippi river.

    Below are the links to see more about these 2  

  5. 0 Votes

    The Nile Perch is devastating the ciclid population of Lake Victoria, East Africa’s largest lake. The nile perch feeds on the native ciclid population and lives for sixteen years growing up to 200 kilograms. Ciclids in Lake Victoria are a very important species to study because there are over 200 species with similar DNA. They are an evolutionary wonder.

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