Picture this: You come home after a long day at work, thinking of what you can make for dinner from last nights leftovers and your store cupboards a la Ready Steady Cook, when you look down and see a dead cockroach on your kitchen floor. Can you imagine anything worse?
How about this: a 300-pound black bear, ready to make a hasty exit through the doorway you’re standing in. That’s something the good people of southern California actually have to worry about. Thing is, the bears, like many other pests around the world, are not native; they were actually introduced. Read on to find out why.
Black bears in Los Angeles County
Black bears are not uncommon in California. In fact, there are plenty in Sierra Nevada mountain range that spans northern and eastern California and Nevada. And in the San Gabriel mountains, near Los Angeles, black bears roamed freely until settlers wiped them out in the early twentieth century.
Then, during the Great Depression, 33 ‘problem’ bears were moved from the Sierra Nevada mountains into the San Gabriel range, a range where such bears had previously thrived. And is located in what is now the most populous county in the United States. Of course, black bears typically avoid humans, so what could possibly go wrong? Well, the city of Monrovia, in the foothills of San Gabriel, reported 464 bear sightings in 2009. That’s an average of about 9 bears sighted each week in an area about the size of the London borough of Lewisham .
Rabbits in Stockholm
Rabbits are not native to Sweden, but they are (or were, anyway) kept as pets. Some time ago, careless rabbit owners released their bunnies into the “wilds” of Stockholm’s parks, and since the non-native creatures had no natural predators and plenty of food available, they did what comes naturally to them. They mated. Fast.
As they grew in numbers destroying all the green spaces, the city employed rabbit hunters. In 2008 and 2009, the hunters bagged more than 9000 rabbits, which brings up an interesting question: what is a city to do with that many carcasses? Well, the hunters freeze and store the bodies until they have enough for a contractor to come and take them to a heating plant, where they are burned to heat homes. An environmental solution to a significant pest control problem which has divided the opinions of Stockholm’s residents.
Cane Toads in Queensland
The cane toad is a large toad native to Central and South America. It eats both living and dead matter, which is unusual amongst toads and frogs but is why the cane toad is able to adapt so easily to other climates.
In 1935 the cane toad was brought to Queensland in an attempt to control the Cane Beetle, which was totally destroying the area’s lucrative sugar cane crops. But the toads didn’t stick around to only eat the recommended beetles. Instead, they invaded the surrounding areas.
When threatened, the cane toad secretes bufotoxin, which not only kills off native reptiles but also contains bufotenin, a Class 1 drug in Australia. Licking the toad can result in mild hallucinations that last for less than an hour or, thanks to the large quantities of other toxins in the secretion, serious illness or death. But hey, some people get their kicks out of doing some pretty weird stuff.
Walking catfish in Florida
The walking catfish is naturally found in Southeast Asia, but when it was discovered in the Florida wilderness in 1967, the locals were not impressed. As long as they stay moist, the catfish can ‘walk’ using its pectoral fins to move from one source of water to another, leading Floridians to dub them ‘Frankenfish’ and ‘the fish from hell’.
The aquarium trade brought the walking catfish to the United States in the 1960s, and its intial introduction to the landscape is believed to have been an accident. It is clear, however, that following a ban on their importation and possession in the late 1960s, more of the catfish were introduced intentionally, after owners ditched them in the wilderness to avoid breaking the ban.
Despite fears that the catfish would decimate native populations of fish, they seemed to have joined the natural balance of the ecosystem, with their numbers levelling off in the 1990s, not undue to Heron intervention.
Rats on Lord Howe Island
Lord Howe Island sits 700 km east of the Australian mainland. An extremely isolated place, it was discovered in 1788 and since then, invasive species have run rampant over the island, threatening the island’s endemic plants and animals.
Having already gotten rid of populations of feral pigs, dogs and cats, the Lord Howe Island Board has decided to tackle the rat population with a plan straight out of the least believeable Hollywood film ever: they will place the native wildlife in captivity, ship out or slaughter cattle and chickens, muzzle pets and keep children indoors. Then they will spread rat poison across the entire island, keeping it on lock-down for 100 days, until the rat problem is eradicated.
If that seems excessive, well, the board spends around $65k a year setting out poisoned traps, and that only covers about 5.6 km2, or 10% of the island. To put into layman’s terms, it’s the equivalent of spending $178 each day or buying 36 x R2-D2 DVD projectors with Millenium Falcon remote control. Every year. And I tell you what, I know someone at home who would be sublimely happy with just one of those things, never mind 36!