Rats have infested the world’s islands

Is there a more idyllic vacation for two than your own island hideaway? Just you and your beloved and nature. Well, and millions of rats.

Global stowaways

Rats have the troubling ability to sneak onto shipping vessels and get off at planned destinations. Or to survive shipwrecks and end up on the first patch of land they can swim onto. And those patches are just about everywhere.

Their talents for stowing away are so legendary that the black rat is also known as the ship rat. They’ve hidden in freight or supply crates or traipsed across rope lines to get into vessels for centuries. They came to Hawaii and New Zealand aboard Polynesian canoes. (We too wondered how large those canoes would have to be for rats to go unnoticed.) It’s said that three rat species from Europe and Asia have become established in 90 percent of the world’s islands and island chains.

For instance, millions of the nasty rodents on South Georgia Island in the South Atlantic descended from the ships of Captain James Cooke, who came ashore in 1775, and the late eighteenth-century whaling and sealing vessels that followed. A four-year period of rat eradication began in 2011.

You might not have wanted to put South Georgia Island on your trip itinerary even if it wasn’t for the wildlife. There’s permanent ice and snow at the higher regions and it’s pretty cold year-round throughout. Still, there’s a tourism industry here, with cruise ships and sailing yacht travelers stopping by, apparently, just to say they did.

You think it’s only the old wooden ships of yesteryear freighting the problem? Think again. Tourists have complained about cruise ship infestations, and headlines such as “Ghost ship carrying cannibal rats could be headed to Britain” filled the media a couple years back. It seems that a Soviet-era cruise ship used for the entertainment of Communist uppity-ups (we’re all equal, but some are more equal than others) ended up abandoned for debts owed. Eventually, the Canadian government let it drift…with a cargo full of hungry, and ultimately, cannibalistic rats.

While you’ll probably stay out of volcanic or Antarctic rocks, the Galapagos Islands off of Ecuador is a chain you might very well want to visit. It offers more of a white sand, blue sea, traditional island adventure. Find yourself a hammock, but please stay away from the chain’s Pinzon Island. Its 180 million rats – pegged at about 10 per square yard – feasted on the island’s bird and tortoise shells until eradication efforts began in 2012.

Much farther north, there’s an entire chain of islands named for their invasive population. The Rat Islands in southwest Alaska are believed to be rat-free since 2009, but that threat has been replaced by volcanic activity and earthquakes. A major quake in 1965 measured 8.7 on the Richter scale.

Beyond the ick factor

The threat goes well beyond the ‘ick’ factor. In addition to causing salmonella, rat-bite fever, rabies and bubonic plague, among other diseases, the rodents eagerly destroy native species.

“Invasive rats are likely the single largest threat to seabirds,” said Bernie Tershy, co-author of a 2008 study of global seabird populations, as reported by the National Geographic Society.

It’s because of this that rat eradication efforts (called “raticides,” naturally) have been undergone all over the world over the last decade or so. New Zealand, for instance, has destroyed the invasive rat populations in more than 100 islands.

Regardless of climate or food sources, rats can live just about anywhere. But don’t let that stop you from your idyllic tropical island vacation. But we advise staying away from Pinzon Island – even if it only contains 180 million brittle rodent skeletons by now.

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By David Searls, Earth.com Staff Writer