We bought a new television set this week and the stink bugs returned. No, these weren’t cause and effect. And normally I wouldn’t mention them in the same breath. Except that I also started reading William Stolzenburg’s new book, Rat Island, this week. Will’s a friend and neighbor here in Shepherdstown WV where we both live. He also happens to be an excellent science writer, the author of hundreds of magazine articles and a previous book, Where the Wild Things Were. His current book chronicles the sorry history of introduced invasive species on islands, and the resulting ecological devastation. Listen to a brief excerpt. [audio:http://amymathewsamos.com/wp-content/uploads/2011/10/rat-island.mp3%5D Listen on iphone/ipad.
Brown marmorated stink bugs in the United States might not be as ecologically evil as rats in the Aleutians, but they’re the most conspicuous and annoying invasive species in my neck of the woods this time of the year, and I couldn’t help but make the connection.
We do have some native stink bugs here but you’d never know it. Sightings are rare and inconsequential and I never even heard the term stink bug until the alien brown marmorated version (Halyomorpha halys) appeared a few years ago. Native to Asia, they arrived in eastern Pennsylvania sometime around 1998 in packing crates, presumably with products imported from China or Japan. According to the University of Pennsylvania’s Entomology Department, they’ve been sighted in at least two dozen states since then and given their numbers locally, seem to be overwhelming potential predators and competitors, as alien invasives are wont to do.
In the fall, they descend on houses in hordes, clinging to window screens and doors hoping
What’s striking about Will’s new book isn’t just the devastation resulting from introduced species (invasives in general often outcompete native species, and predatory species released on islands can wipe out entire populations), or how ubiquitous they are (the International Union for the Conservation of Nature recognizes invasive species as one of the top threats to global biodiversity). It’s how long this has been going on and how often the story is repeated. Will reveals how paleontologists have traced the movement of Polynesian people throughout the south Pacific over thousands of years of expansion by uncovering the remains of now extinct birds in ancient hearths and middens. It seems that as they moved inexorably from one island to the next, Polynesians wiped out entire species of uniquely adapted birds that had evolved in isolation, free of ground predators, on each island chain. Having evolved without them, these birds had no defenses against the new human invaders who hunted them for food and feathers or the dogs, pigs, and rats these people brought with them. It’s now clear that paradise had been ransacked long before Captain Cook sailed the seas: Hawaii alone had lost an estimated half of its bird species by the time Europeans arrived.
In turn, the Europeans did no better. In New Zealand, they released cats to hunt the rats and introduced rabbits for game. Later, they brought in ferrets and weasels to attack the irrupting rabbits that had grazed the sheep pastures to nubs. Predictably, the alien predators hunted local birds as well as their intended targets, and each new introduction brought new destruction. Yet each time New Zealanders failed to learn the lesson from the past.
One can only wonder: surely the Polynesians must have seen signs that their supply of favored birds was running low. Once they had opened the Pandora’s box of rats it could never to be contained again. But could they not control their own hunting for decorative feathers? In New Zealand, naturalists warned that the birds were disappearing, yet the release of predators continued. It all seems so reckless and decadent.
Which brings me back to our new television set. A Panasonic. From Asia. Maybe. It’s a Japanese company, but manufacturing occurs all over the world so we’re not really sure where it came from. Which is kind of the point. Raw materials and finished products alike routinely are transported from one ecoregion to another, and creatures inevitably hitch a ride. Our last television worked just fine until the cable company converted to digital and placed a helpful message on the screen telling us we were obsolete if we tried to tune in. We thought about getting a digital converter box and rigging up the old set for another few years. But it already was on its second life, having been rescued from a seeming warehouse of unwanted electronics in a friend’s basement, one of many discarded victims of her husband’s frequent upgrades to the latest models. Rather than convert, or explore whether our friend’s electronics graveyard was still available for looting, we indulged.
But then I read about the Polynesians. And the New Zealanders. And I wondered: was our consumption in fact overconsumption? By indulging in something we don’t really need, are we re-enacting what the Polynesians did on dozens of islands for thousands of years? Okay, maybe that’s a bit melodramatic. It’s just one television. Chances are our new TV isn’t giving some voracious stowaway a free ride to a new land of milk and honey. But still. Looking at the trend over time, it’s hard not to conclude that we humans like our pretty feathered capes and our high def images more than we like intact ecosystems. Just as we have for thousands of years, we figure just one more won’t hurt anything, and we’re willing to take that chance. Again and again. Just one more time.