Posts Tagged ‘invasive species’
“I discovered that if one looks a little closer at this beautiful world, there are always red ants underneath”*…

E.O. Wilson once observed that “Ants have the most complicated social organization on earth next to humans.” John Whitfield explores the way in which, over the past four centuries, quadrillions of ants have created a strange and turbulent global society that shadows our own…
It is a familiar story: a small group of animals living in a wooded grassland begin, against all odds, to populate Earth. At first, they occupy a specific ecological place in the landscape, kept in check by other species. Then something changes. The animals find a way to travel to new places. They learn to cope with unpredictability. They adapt to new kinds of food and shelter. They are clever. And they are aggressive.
In the new places, the old limits are missing. As their population grows and their reach expands, the animals lay claim to more territories, reshaping the relationships in each new landscape by eliminating some species and nurturing others. Over time, they create the largest animal societies, in terms of numbers of individuals, that the planet has ever known. And at the borders of those societies, they fight the most destructive within-species conflicts, in terms of individual fatalities, that the planet has ever known.
This might sound like our story: the story of a hominin species, living in tropical Africa a few million years ago, becoming global. Instead, it is the story of a group of ant species, living in Central and South America a few hundred years ago, who spread across the planet by weaving themselves into European networks of exploration, trade, colonisation and war – some even stowed away on the 16th-century Spanish galleons that carried silver across the Pacific from Acapulco to Manila. During the past four centuries, these animals have globalised their societies alongside our own.
It is tempting to look for parallels with human empires. Perhaps it is impossible not to see rhymes between the natural and human worlds, and as a science journalist I’ve contributed more than my share. But just because words rhyme, it doesn’t mean their definitions align. Global ant societies are not simply echoes of human struggles for power. They are something new in the world, existing at a scale we can measure but struggle to grasp: there are roughly 200,000 times more ants on our planet than the 100 billion stars in the Milky Way…
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The more I learn, the more I am struck by the ants’ strangeness rather than their similarities with human society. There is another way to be a globalised society – one that is utterly unlike our own. I am not even sure we have the language to convey, for example, a colony’s ability to take bits of information from thousands of tiny brains and turn it into a distributed, constantly updated picture of their world. Even ‘smell’ seems a feeble word to describe the ability of ants’ antennae to read chemicals on the air and on each other. How can we imagine a life where sight goes almost unused and scent forms the primary channel of information, where chemical signals show the way to food, or mobilise a response to threats, or distinguish queens from workers and the living from the dead?
As our world turns alien, trying to think like an alien will be a better route to finding the imagination and humility needed to keep up with the changes than looking for ways in which other species are like us. But trying to think like an ant, rather than thinking about how ants are like us, is not to say that I welcome our unicolonial insect underlords. Calamities follow in the wake of globalised ant societies. Most troubling among these is the way that unicolonial species can overwhelmingly alter ecological diversity when they arrive somewhere new. Unicolonial ants can turn a patchwork of colonies created by different ant species into a landscape dominated by a single group. As a result, textured and complex ecological communities become simpler, less diverse and, crucially, less different to each other. This is not just a process; it is an era. The current period in which a relatively small number of super-spreading animals and plants expands across Earth is sometimes called the Homogecene. It’s not a cheering word, presaging an environment that favours the most pestilential animals, plants and microbes. Unicolonial ants contribute to a more homogenous future, but they also speak to life’s ability to escape our grasp, regardless of how we might try to order and exploit the world. And there’s something hopeful about that, for the planet, if not for us.
The scale and spread of ant societies is a reminder that humans should not confuse impact with control. We may be able to change our environment, but we’re almost powerless when it comes to manipulating our world exactly how we want. The global society of ants reminds us that we cannot know how other species will respond to our reshaping of the world, only that they will…
Bracing: “Ant geopolitics,” from @gentraso in @aeonmag.
* David Lynch
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As we investigate insects, we might spare a thought for Sara Josephine Baker; she died on this date in 1945. A physician, she was a pioneer in public health and child welfare in the United States in her roles as assistant to the Commissioner for Public Health of New York City, and later, head of the city’s Department of Health in “Hell’s Kitchen” for 25 years. Convinced of the value of well-baby care and the prevention of disease, in 1908 she founded the Bureau of Child Hygiene– and decreased the death rate by 1200 from the previous year. Her work made the New York City infant mortality rate the lowest in the USA or Europe at the time. She set up free milk clinics, licensed midwives, and taught the use of silver nitrate to prevent blindness in newborns.
Baker is also remembered as the public health official who (twice) tracked down “Typhoid Mary.”
“Round and round they went with their snakes, snakily”*…

Florida…
Burmese pythons are too good at what they do — they’re nearly undetectable to both humans and their prey, they barely need to move and when they do they’re deadly. On top of that, they have lots of babies.
As a result, according to an ambitious new paper produced by the U.S. Geological Survey, their population has exploded in only 20 years from a few snakes at the southern tip of Everglades National Park to an invasion that envelops the southern third of Florida…
The success of these snakes, which are native to Southeast Asia, and came here via the exotic pet trade, has been a cataclysmic failure for South Florida ecosystems and “represent one of the most intractable invasive-species management issues across the globe,” said the paper…
When biologists open the invasive snakes up, it’s like rifling through a Florida field guide. All told, they’ve found 76 prey species inside the snakes. That includes lots of birds, such as vultures, crows, ducks, herons, roseate spoonbills and threatened wood storks; small mammals such as the endangered Key Largo woodrat and Key Largo cotton mouse, marsh rabbits, armadillos, possums, raccoons, otters and domestic cats, and larger prey including domestic goats, white-tailed deer, wild hogs and alligators….
How much damage have they done? Guzy points out that before 2000, researchers could frequently spot mammals in Everglades National Park. But from 2003 to 2011, the frequency of mammal observations [raccoons, opossums, bobcats, rabbits, gray foxes, and white-tailed deer] declined by 85% to 100%. Outside the python’s range, those species were more common.
Snakes on a plain: “Python invasion has exploded out of the Everglades and into nearly all of southern Florida,” from @SunSentinel.
* Aldous Huxley, Brave New World
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As we tread carefully, we might recall that it was on this date in 2006 that New Line Cinema ordered five days of additional shooting on what had been a minor film in their 2006 line-up, Pacific Air Flight 121 (principal photography had wrapped in September 2005). While re-shoots normally imply problems with a film, the producers opted to add new scenes to the film to change the MPAA rating from PG-13 to R and bring it in line with growing fan expectations… expectations that had been raised when (at star Samuel L. Jackson’s insistence) the film’s title had reverted to its original working form: Snakes on a Plane.
More than 450 snakes were used for filming to represent 30 different species of snakes, including a 19-foot (5.8 m) Burmese python named Kitty.
“What’s in a name?”*…
How to rid the Midwest of an invasive aquatic species? As Sarah Kuta explains, the State of Illinois hopes that it can convince its citizens to help…
For decades, invasive species of carp have been wreaking havoc on lakes and waterways in the American Midwest. One way to help tackle the infestation is simply to catch, cook and eat the fish, but many diners turn up their noses when they hear the word carp.
Now, the Illinois Department of Natural Resources and other partners hope that giving the fish a fresh new image will make them more appealing to eat. They’ve given the invasive species a new name, “copi,” in hopes that people will order copi dishes at restaurants or even cook up the fish at home.
… carp began to spread widely when the other four carp species were imported to the United States in the 1960s and ‘70s to eat algae in wastewater treatment plants and aquaculture ponds, as well as to serve as a source of food.
The fish escaped into the Mississippi River, then continued their spread into other rivers and beyond. Their population grew quickly, and they began to crowd out native fish species, outcompeting them for food (different carp species feed on plants, plankton, on up in size to endangered freshwater snail species). Invasive carp are also thought to lower water quality, which ultimately harms underwater ecosystems and can kill off other native species like freshwater mussels. (The fish were once collectively called “Asian carp,” but state governments and federal agencies now refer to them as “invasive carp” because of concerns over bigotry toward Asian culture and people.)
Federal, state and local officials have since spent hundreds of millions of dollars trying to keep the invasive fish in check, and most importantly, out of the Great Lakes. If the fish swim into Lake Michigan, they could threaten the commercial fishing and tourism industries, which together are responsible for billions of dollars of economic activity…
The new name comes from the word “copious,” a nod to the sheer abundance of these fish…
From the Annals of Marketing: “Can Rebranding Invasive Carp Make It More Appealing to Eat?,” from @SarahKuta in @SmithsonianMag.
* Shakespeare, Romeo and Juliet
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As we dig in, we might recall that on this date in 1862 (88 years after the Declaration of Independence was adopted by the Second Continental Congress on this same date), Charles Lutwidge Dodgson, a young Oxford mathematics don, took the daughters of the Dean of Christ Church College– Alice Liddell and her sisters– on a boating picnic on the River Thames in Oxford. To amuse the children he told them the story of a little girl, bored by a riverbank, whose adventure begins when she tumbles down a rabbit hole into a topsy-turvy world called “Wonderland.” The story so captivated the 10-year-old Alice that she begged him to write it down. The result was Alice’s Adventures in Wonderland, published in 1865 under the pen name “Lewis Carroll,” with illustrations by John Tenniel.
“Now I wanna remind everyone of the House of Mouse Rules: No smoking. No villainous schemes. And no guests eating other guests.”*…
In addition to being home to men with questionable decision-making skills, Florida also seems to have some issues with bizarre animal behavior, whether it’s freezing iguanas dropping from trees or alligators battling pythons in the Everglades. When it comes to those animals, however, Floridians can truly put the blame on non-natives. Neither pythons nor green iguanas made the Sunshine State their home until we brought them there as pets.
In fact, there are lots of problematic invasive species that have spread through the pet trade, from predatory fish that can drag themselves between bodies of water to a crayfish that clones itself to reproduce. Those high-profile cases lead to some obvious questions, like whether pets really are more likely to be invasive and, if so, why?
Two Swiss researchers, Jérôme Gippeta and Cleo Bertelsmeier have now attempted to answer these questions. And their conclusion is that yes, our pets are more likely to be problems.
To answer the question of whether pets really are problematic, the researchers generated some basic statistics for different groups of animals (mammals, birds, reptiles, amphibians, and fish). These included estimates of the total number of species, as well as the number of those that are classified as invasive and the number that are part of the pet trade.
If pets were no more or less likely to be invasive, you’d expect to see the invasive ones occupy similar fractions of both the pet trade and the total number of species in that group. But that’s not what we see in any of the groups. Invasive mammal species were present at five times the rate in the pet trade as they are in the wild around the globe. There was a similar result in birds; for amphibians, invasive species were eight times more common in the pet trade and about 10 times more common in fish.
Overall, invasive species were 7.4 times more likely to be kept as pets than you’d expect based on their frequency among vertebrate populations.
But cause and effect can be difficult to disentangle. Do we choose species that are more likely to be invasive as pets? Or have pets ended up with more opportunities to invade new environments because we transport them around the world?…
Spoiler alert: it’s the former… A new study finds the factors making them easier to keep also help them spread: “Unfortunately, we like pets that are likely to be invasive species.”
* Mickey Mouse
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As we ponder proliferation, we might recall that it was on this date in 1964 that a different kind of “invader,” the Beatles, set a record: they became the first artists to hold all top 5 spots on the Billboard Hot 100 on the same week, on April 4, 1964.
#1. Can’t Buy Me Love
#2. Twist and Shout
#3. She Loves You
#4. I Want to Hold Your Hand
#5. Please Please Me.
More Beatles on the Charts that week: #31 – I Saw Her Standing There, #41 – From Me To You, #46 – Do You Want To Know a Secret, #58 – All My Loving, #65 – You Can’t Do That, #68 – Roll Over Beethoven, #79 – Thank You Girl
At the time, the best-selling piece of Beatles merchandise was the “I Love Ringo” button.







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