by Tom Phillips
Ironically, after the initial fuck-up of introducing rabbits into Australia in the first place, the eventual solution was also a fuck-up. For several decades Australian scientists had been experimenting with using biological warfare on the rabbits: introducing diseases in the hope that they’d be killed off, most famously myxomatosis in the 1950s. That worked pretty well for a while, reducing the rabbit population dramatically, but it didn’t stick. It relied on mosquitoes to transmit the virus, so wasn’t effective in areas where mosquitoes wouldn’t breed, and eventually the surviving rabbits developed resistance to the disease and numbers started climbing again.
But the scientists carried on researching new biological agents. In the 1990s, they were working on rabbit hemorrhagic disease virus. Now, experimenting with diseases is a dangerous business, and so the scientists were doing their work on an island off the south coast, to reduce the risk of the virus getting loose and spreading to the mainland. Go on. Guess what happened.
Yep, in 1995, the virus got loose and spread to the mainland. Life broke free, in this case by hitching a ride on some flies. But having accidentally released a deadly (to rabbits) pathogen into the wild, the scientists were rather pleased to note that...it seemed to be working. In the twenty years since rabbit hemorrhagic disease virus was mistakenly released into the wild, rabbit populations in South Australia have declined again, while vegetation has returned and the many animals that had been pushed to the brink of extinction have seen their numbers surge back. Let’s just hope that rabbit hemorrhagic disease virus doesn’t turn out to have any other side effects.
Australia’s rabbits are far from alone in proving that sometimes we should leave animals and plants where we found them.
Like the Nile perch, a six-foot-long ravenous predator that, as you might guess from the name, comes from the Nile. However, the British colonizers of East Africa had bigger plans for it. They thought it would be a terribly good idea to introduce it into Lake Victoria, the largest lake in Africa. Lake Victoria already had lots of fish in it, and local fishermen were perfectly content fishing those fish, but the British thought that this situation could be improved. The biggest group of fish in the lake at the time were hundreds of different species of cichlids, those small, adorable-looking fish beloved of aquarium keepers. Unfortunately for the cichlids, the British colonial officials hated them, describing them as “trash fish.”
A man carries an 80-kilogram Nile perch in Uganda
They decided that Lake Victoria would be much better with bigger, cooler fish in it. It would make for superior fishing, they reckoned. Lots of biologists warned them that this was not a great idea, but in 1954 they went ahead and introduced the Nile perch into the lake. The Nile perch then did what Nile perch do: they ate their way through species after species.
The British officials were right about one thing, in that it really did make for superior fishing. The fishing industry boomed, with Nile perch proving immensely popular both as a commercial catch for food and an enjoyable catch for sport. But while the value of the fishing industry shot up by 500 percent, supporting hundreds of thousands of jobs, the number of species in Lake Victoria plummeted. More than 500 other species became extinct, including over 200 species of the poor unfortunate cichlids.
It’s not just animals that can get out of control. Kudzu, a vine common across Asia, was widely introduced into the USA in the 1930s in an attempt to solve a problem that we’ve already mentioned: the Dust Bowl. Officials hoped that the fast-growing vine would help knot the soil back together and prevent further erosion. And it was quite good at that. Unfortunately, it was also quite good at smothering other plants and trees, as well as houses, cars and anything else it came across. It became so widespread across the southern United States that it was given the nickname “the vine that ate the South.”
In fairness to kudzu, it isn’t quite the triffid-like demon plant that some mythology suggests, and recent studies have found it covers less land than commonly thought. Still, there’s an awful lot of it where 80 years ago there wasn’t any of it, and it remains officially listed by the US government as a “noxious weed.”
But now might be the time to start feeling sorry for it, because the invasive species has gained an invasive species of its own. Sometime in 2009, the Japanese kudzu bug managed to make its way across the Pacific, and must have been delighted on landing in Atlanta to discover that there was a load of kudzu already there for it to eat. In the space of three years, it had spread through three states, wiping out as much as a third of the kudzu’s biomass. In case you’re thinking, well, that’s good, kudzu problem solved, it’s unfortunately not quite that simple: kudzu bugs also destroy soy crops, a major source of income in many of the affected states. The accidental solution to one problem might turn out to be a much bigger problem in its own right.
Our apparent desire to introduce new species where they’ve no right to be doesn’t even stop at species that already exist: sometimes we manage to create whole new species. That’s what happened in 1956 when the Brazilian scientist Warwick Estevam Kerr imported some African queen bees from Tanzania, in an effort to cross-breed them with European bees—the hope being that their combined traits would produce a species better suited to the Brazilian environment.
Unfortunately, after a year of breeding experiments, the thing that was always going to happen happened. A beekeeper working at Kerr’s lab in Rio Claro, a city to the south of São Paulo, had a very bad day on the job. Twenty-six of the Tanzanian queen bees escaped, followed closely by their personal swarms of European bees, and set up home in Brazil. The queens started breeding indiscriminately with any male bees they came across, producing hybrid strains with several different species. These new “Africanized” bees started spreading rapidly across South America, then Central America and then into the USA. They’re actually smaller and have less venom than the bees that came before them, but they are way more aggressive at defending their hives—producing up to ten times the number of stings. As many as a thousand people have died as a result of those stings, which is why the bees have ended up with the nickname “killer bees.” Which is a bit unfair. They’re just misunderstood.
But in the annals of humans learning the very hard way that ecosystems are complicated and that messing with the delicate balance of nature will come back to bite you, two stories stand out above all else. On different sides of the world, several decades apart, a fanatical dictator and an eccentric literature lover made mirror-image mistakes that had profound consequences. Both of their mistakes came from the same source: they radically underestimated birds.
Don’t Underestimate Birds, Part I: A Pest Too Far
Mao Zedong’s Four Pests campaign has to rank as the most disastrous entirely successful public health policy ever. It pulled together every part of society to meet its goals, which it surpassed to an astonishing degree—and half of those goals almost certainly resulted in major widespread improvements to the health of the nation. Two out of four isn’t bad, you might think.
The trouble is that the fourth goal resulted in tens of millions of deaths.
The problem stems from that same failure to realize that ecosystems are complicated and unpredictable. Oh yeah, let’s just add a species here, maybe trim a couple of species there, we think. That’ll make everything better. At which point Unintended Consequences rocks up with her pals Knock-On Effects and Cascading Failure and throws a hubris party.
When Chairman Mao’s communists took power in China in late 1949, the country was in the grip of a medical crisis. Infectious diseases, from cholera to plague to malaria, were running rife. If Mao’s goal of rapidly transforming the country from a largely agrarian nation only a few decades out of feudalism into a modern industrial powerhouse were to be met, something would have to be done.
Some of the solutions were obvious and sensible—mass vaccination programs, improved sanitation, that sort of thing. The problems
started when Mao decided to focus on blaming animals for the country’s woes.
Mosquitoes spread malaria, rats spread plague; that much was pretty undeniable. And so a nationwide plan to reduce their numbers was hatched. Unfortunately, Mao didn’t stop there. If it had just been a Two Pests campaign, then things might have worked out okay. But Mao decided (without bothering to do anything like, you know, ask experts their opinion or anything) to add in two other species, as well. Flies were to be wiped out, on the grounds that flies are annoying. And the fourth pest? Sparrows.
The problem with sparrows, the thinking went, was that they ate grain. A single sparrow could eat as much as 4.5 kilograms of grain every single year—grain that could be used instead to feed the people of China. They did the math and determined that 60,000 extra people could be fed for every million sparrows that were eliminated. Who could argue with that?
The Four Pests campaign began in 1958, and it was a remarkable effort. A countrywide poster campaign demanded that every citizen, from the youngest to the oldest, do their duty and kill the shit out of as many animals as possible. “Birds,” it was declared, “are public animals of capitalism.” The people were armed with everything from flyswatters to rifles, with schoolchildren being trained in how to shoot down as many sparrows as possible. Jubilant sparrow-hating crowds took to the streets waving flags as they joined battle with the birds. Sparrows’ nests were destroyed and their eggs smashed, while citizens banging pots and pans would drive them from trees so they could never rest until, exhausted, they fell dead from the sky. In Shanghai alone, it was estimated that almost 200,000 sparrows died on the first day of hostilities. “No warrior shall be withdrawn,” the People’s Daily wrote, “until the battle is won.”
The battle was, indeed, won. In terms of achieving its stated goals, it was a triumph—an overwhelming victory for humanity against the forces of small animals. In total, the Four Pests campaign is estimated to have killed 1.5 billion rats, 11 million kilograms of mosquitoes, 100 million kilograms of flies...and a billion sparrows.
Unfortunately, it quickly became apparent what the problem with this was: those billion sparrows hadn’t just been eating grain. They’d also been eating insects. In particular, they ate locusts.
Suddenly freed from the constraints of a billion predators keeping their numbers down, the locusts of China celebrated like it was New Year every day. Unlike sparrows—who’d eat a bit of grain here and there—the locusts tore through the crops of China in vast, relentless devouring clouds. In 1959, an actual expert (ornithologist Tso-hsin Cheng, who had been trying to warn people how bad an idea this all was) was finally listened to, and sparrows were replaced on the list of official pests-we-want-to-kill by bedbugs. But by then it was too late; you can’t just replace a billion sparrows on a whim once you’ve wiped them out.
To be clear, the destruction of the sparrows wasn’t the only cause of the great famine that struck China in the years between 1959 and 1962—a perfect storm of terrible decisions helped to cause it. A Party-mandated shift from traditional subsistence farming to high-value cash crops, a suite of destructive new agricultural techniques based on the pseudoscience of the Soviet biologist Trofim Lysenko and the central government appropriating all produce and diverting it away from local communities each played its part. Incentives that pushed officials at every level to report positive results led to the delusion on the part of the country’s leaders that, basically, Everything Was Fine and the nation had more than enough food. This meant that when several years of terrible weather hit (flooding in some parts of the country, drought in others), there were no reserves to see them through.
But all that sparrow-murdering, and the subsequent obliteration of crops by the real pests, was a crucial component of the disaster that struck. Estimates of the number of deaths in the famine range from 15 million to 30 million, and the fact that we don’t even know whether or not 15 million human beings died just adds an extra layer of horror to it.
You’d hope that the basic lesson of this—don’t fuck with nature unless you’re very, very certain what the consequences will be, and even then it’s probably still not a good idea—would have stuck. But that seems unlikely. In 2004, the Chinese government ordered the mass extermination of mammals from civet cats to badgers in response to the outbreak of the SARS virus, suggesting that humans’ capacity for learning from their mistakes remains as tenuous as ever.
Don’t Underestimate Birds, Part II: Shakespeare in the Park
Eugene Schieffelin made basically the same mistake as Chairman Mao, except in the opposite direction. And where Mao’s error was driven by a combination of public health goals and dictatorial fiat, the havoc that Schieffelin caused in his ecosystem—a man-made natural disaster that continues to this day—was driven entirely by whimsy.
What Schieffelin did one cold early spring day in 1890 has ended up spreading disease, destroying hundreds of millions of dollars’ worth of crops every year and even killed 62 people in a plane crash. Which is quite a lot of damage for someone who was just trying to show off what a huge fan of Shakespeare he was.
Schieffelin was a well-to-do drug manufacturer who lived in New York City, but despite the strong potential for damaging screw-ups in that line of work, his contribution to environmental chaos stems not from his profession, but rather from his hobbies. He was extremely keen on two fashionable trends of the age—an absolute devotion to the works of Shakespeare, and transplanting species into new habitats.
At the time, Western culture was going through an all-consuming Shakespeare revival, with the result that the Bard had attained a status in popular culture that was at roughly Beyoncé levels. Meanwhile, based on a French idea, groups called “acclimatization societies” had started spreading around the Western world—voluntary groups of wealthy do-gooders who devoted themselves to introducing foreign species of plants and animals to their countries. (This was many years before people would twig just what an awful idea that could be.)
Schieffelin’s mistake stemmed from the fact that he was the chairman of the American Acclimatization Society, based in New York, and also that he absolutely bloody loved Shakespeare. And so he hit on a delightful, eccentric plan: what better way to honor the greatest poet in the English language, he thought, than to introduce every single species of bird mentioned in Shakespeare’s plays to the USA? The American Acclimatization Society set to work.
At first, they ran up against a string of failures: birds such as skylarks, bullfinches and song thrushes were released into the wild (well, the city, at least) but failed to take hold, dying out after a few years in the unfamiliar environment. But then, on March 6, 1890, Eugene Schieffelin stood in Central Park with his assistants and began opening a number of cages that contained a total of 60 European starlings.
You can’t really blame Shakespeare for all this, but if he’d chosen a different bit of hyperbole in Act I, Scene III of Henry IV, Part I, then things would have been very different. In that scene, the character Hotspur, describing his determination to keep pressure on the king to pay a ransom for his brother-in-law Mortimer (despite the king forbidding him to even mention Mortimer’s name), says:
Nay,
I’ll have a starling shall be taught to speak
Nothing but “Mortimer,” and give it him
To keep his anger still in motion.
That’s the only time Shakespeare ever mentions starlings. The whole of the rest of the complete works, not a dicky bird. But that single reference was enough for our Eugene.
Those initial 60 starlings were released in 1890, and in 1891 Schieffelin went back and released 40 more. Initially, it didn’t look great for the first American starlings—within a few years of bitter New York winters, only 32 of the original hundred were still alive, and it looked like they might follow in the wingbeats of their unlucky predecessors. But starlings are tough, versatile creatures, adept at fitting into new environme
nts and bullying their way to survival. In an impressive bit of irony, a small flock of them found shelter from the elements under the eaves of the American Museum of Natural History—a building dedicated to preserving the nation’s natural history inadvertently helped to alter that history dramatically. Because gradually, the starlings’ numbers began to grow. And grow. And grow.
Before the decade was out, they were common across New York City. By the 1920s, they’d spread halfway across the country. By the 1950s, they were in California. Today, there are 200 million of the buggers living all across North America, and you can find them everywhere from Mexico to Alaska.
They have become, in the words of the New York Times, “one of the costliest and most noxious birds on our continent”—or, as the Washington Post once described them, “arguably the most hated bird in North America.” Flocking together in huge murmurations that can number up to a million birds, they destroy crops on a vast scale, tearing through wheat fields and potato fields alike and obliterating grain stores. They are aggressive, chasing native bird species out of their nests, and they help spread diseases that affect both humans and livestock, from fungal infections to salmonella. They shit absolutely everywhere, and it smells awful.
Their massive flocks also pose a danger to air travel—in Boston in 1960, an estimated 10,000 starlings flew into a plane as it took off from Logan Airport, destroying its engines and sending it crashing to the ground, where 62 of the 72 passengers on board died.
Starlings are a pest, a health hazard and a significant financial drain on the agricultural economy of North America. The only reason they’re even present on the continent is because a nice upper-middle-class chap was way too into his hobbies and didn’t stop to think about the potential consequences. If he’d got into jogging or home-brewing or watercolors instead, none of this would have happened.