Whether put there on purpose or accidentally, wild invaders who have been introduced to new locations can often have a negative impact. The six troublesome animals below are causing havoc for the native species in the places they have invaded:
- Grey squirrels in Britain
The native North American grey squirrels were originally introduced in Great Britain in 1876 as a fashionable addition to country estates. Unfortunately, the grey squirrel has driven out the native red squirrels. Not only are the grays bigger and stronger than the reds, they also carry a virus that the reds have no immunity to fight off. Today, there are less than 150,000 red squirrels remaining in Britain. Fortunately, Scotland has retained their red squirrel population with conservation projects to protect them.
- Camels in Australia
Brought over by the Europeans in the mid 1800’s for use as work animals, camels now number around 500 thousand in the Australian outback. Unfortunately, due to their voracious thirst, the camels drain water holes and deprive native species of their share of the water. The camels don’t even have jobs anymore, having been replaced by trucks and trains long ago. To combat these now-wild camels from invading sacred waterholes, man-made water sources are being introduced to attract them away.
- Burmese pythons in Florida
No one knows for sure, but the Burmese pythons now invading the Florida Everglades National Park are thought to be escaped pets at one time. Because a single female can lay up to 100 eggs, the Burmese pythons have swollen in population size. The snakes have huge appetites as well, surpassing the alligator as the area’s top predator. Burmese pythons feast on deer, bobcats, rabbits, raccoons and possums, leading to their sharp decline. Impossible to spot when hiding, it is impossible to guess how many are lurking in the habitat.
- Parakeets in London
Known as the city’s “posh pigeons”, these tropical birds are typically native to West Africa and India. The theory is that the current breeding population going wild in London originally came from escaped birds used in the filming of The African Queen. Others think that the original birds were escapees from the Syon Park apiary. A wild rumor of Jimi Hendrix releasing the parakeets in 1970 is also cited for the population of parakeets. Though colorful and unusual, the parakeets unfortunately scare away native birds from nesting and feeding sites that should be their own.
- Zebra mussels in the Great Lakes
The Zebra mussel is native to the Caspian and Black seas. This species was introduced to the Great Lakes, which border the U.S. and Canada, via the ballast water from navy war ships. One of the most invasive freshwater mollusks on the planet, the Zebra mussel grows exponentially in numbers at an alarming rate. Because the Zebra mussels ravenously consume all the plankton and algae, native species are left to starve.
- Lionfish in the Caribbean
A Pacific Ocean native, the red lionfish is extremely venomous and has few natural predators. Unfortunately for the Western Atlantic, the red lionfish has been multiplying there and spreading throughout the Caribbean coral reefs and into the Gulf of Mexico. Unsure of how the red lionfish came to be in these new waters, their presence is often blamed on Hurricane Andrew. Whatever the reason for the red lionfish invasion, it is destroying the Caribbean eco-system. The red lionfish gobbles up the small reef fish and leave none for the native species.
