7 Facts About Nutria, the Invasive Rodents Taking Over Louisiana

Rodents of Unusual Size/Tilapia Film
Rodents of Unusual Size/Tilapia Film

Rodents are known for being pests, but the nutria may be the worst of them. The orange-toothed, semi-aquatic rodents from South America, which can grow to be up to 20 pounds, have become invasive species whose territory extends to almost every continent on earth. Along the way, they’ve created environmental catastrophes, destroyed infrastructure and crops, and created millions of dollars in damages. The pesky creatures are the subject of a new documentary, Rodents of Unusual Size. The 71-minute film traces the nutria’s rise in Louisiana and the profound consequences it has had on the ecosystem there. Here are seven facts about the animals we learned from the documentary.

1. THEY’RE NOT FROM AROUND HERE.

Nutria are native to South America, but over the past century or so, they have traveled around the globe. In some places, they’re better known as coypu, from the Spanish word coipú. (In Spanish, the word nutria means otter.)

While Rodents of Unusual Size focuses on a small community in southern Louisiana, nutria pose a significant problem elsewhere, too. In the late 19th and early 20th centuries, fur farmers and trappers brought them to Europe, Asia, and Africa as well as a number of places in North America to raise them for their pelts. (Some U.S. states also imported them as a method of weed control.) Unfortunately, that led to the rise of feral populations that have since ballooned. The Invasive Species Specialist Group has named nutria one of the world’s top 100 worst invasive species.

2. THEY MAKE A LOT OF BABIES.

One of the reasons nutria pose such a big problem as an invasive species is that they multiply rapidly. They reach sexual maturity at only a few months old, can reproduce up to three times a year, and in extreme cases, can have litters of up to 13. Though they typically only live between three and six years in the wild, they’re such prolific breeders that, as one invasive species project notes, even in that short time frame, “the amount of offspring produced is tremendous.”

3. AS AN INVASIVE SPECIES, THEY’RE REALLY BAD FOR THE ECOSYSTEM.

The snout of a nutria on a black background with the words 'Rodents of Unusual Size'

Growing up in Delacroix, an island community just south of New Orleans, “it was a jungle,” lifelong resident Thomas Gonzales explains in the opening minutes of Rodents of Unusual Size. “There was nothing but big oak trees. When I look out now, it looks like a disaster.”

Nutria, which can consume up to 20 percent of their body weight in plant matter and roots each day, eat up the vegetation that holds together wetland soil, causing major erosion. What was once wetland becomes open water, permanently. “All the grass that the muskrats used to eat, they cleaned it like a baseball field,” Gonzales says. “Now it’s all water.”

He’s not exaggerating. While storms, dredging, and other factors have also played a role in the environmental decline of places like Delacroix, between 2001 and 2016, overgrazing nutria contributed to the conversion of almost 26,800 acres of Louisiana marsh to open water, the state estimates. And since marshes serve as important protection against storm surges, that also leads to greater flooding inland.

Nutria also pose problems in other arenas: The animals dig extensive burrow systems that sometimes end up under roads, around bridges, and in canals and levees. They also destroy thousands of dollars worth of crops like sugarcane and rice each year, and do millions of dollars of damage to golf courses.

4. THEY WERE ONCE BIG BUSINESS.

The nutria’s rise to global domination is largely thanks to the fur industry. In Louisiana, for instance, fur farmers brought them up from Argentina to raise for their pelts in the 1930s. Some of those animals either escaped or were released, taking up residence along the Gulf Coast, where they flourished in the swamps and other wetlands. By the 1960s, nutria were the Louisiana fur industry’s biggest commodity, with trappers bringing in more nutria and selling the pelts for more money than any other animal. In the 1970s, nutria trapping brought in 1.9 million pelts per year [PDF]. Unfortunately, the overabundance of nutria meant that supply eventually outstripped demand—which was falling across the fur industry anyway—and prices fell steeply over the next few decades. Trapping nutria was no longer as profitable, so trappers found work elsewhere. And without the fur industry keeping the nutria in check, the animal's populations exploded.

5. PEOPLE STILL DEPEND ON THEM FOR THEIR LIVELIHOODS.

A man with a gun over his shoulder standing in a boat filled with nutria carcases
Thomas Gonzales of Delacroix Island, Louisiana

Now, as the environmental impact of nutria has become more apparent, the state of Louisiana is trying to bring back nutria trapping. In order to incentivize trappers to hunt down nutria, the state has a $5 bounty on nutria tails. During the nutria hunting season, from November to March, the state sets up collection stations where trappers can bring in the tails of nutria they have killed [PDF]. They get a check in the mail based on the number of tails they bring in, and can use the carcasses however they want—whether that’s selling them for their fur or meat or discarding them. (Sometimes fur dealers are even on hand at collection stations.) Since the program first began in 2002, it has resulted in the removal of 5 million nutria.

6. WEARING THEIR FUR IS CONSIDERED ETHICAL.

Nutria were originally valued for their pelts, and nutria fur may be making a comeback. In most of the world, killing nutria does a service to the environment, making the rodents one of the most ethical sources of fur around.

“Traditionally, the stigma of fur is that people don’t feel comfortable killing animals to adorn themselves,” fashion designer Cree McCree explains in the film. “But the thing with the nutria is that they’re being killed anyway, and they’re throwing these beautiful furs away. It seemed like a colossal waste.” So McCree founded Righteous Fur, a collective of fashion designers who incorporate nutria fur into their designs, making everything from coats and hats to bow ties. Since most faux fur is made of polyester or other plastics, wearing nutria might actually be more sustainable than sporting fake fur.

7. YOU CAN—AND SHOULD—EAT THEM.

A woman sits at a table covered in nutria pelts.
Cree McCree, founder of Righteous Furs

While people may be turned off by the idea of eating a giant rodent with big orange teeth, nutria actually make a pretty good addition to the dinner table, according to chefs and hunters. “If you approach it with an open mind, you’ll find it doesn’t have a really bad, swampy taste,” award-winning New Orleans chef Susan Spicer says in Rodents of Unusual Size. “The nutria flavor is sort of like the zucchini of the animal world. You can kind of make it work with a lot of different kinds of flavors.”

The meat is lean, and, unlike with other meats, you don’t have to worry about feeling bad that a cute critter died for your dinner. In fact, you’re doing the environment a service. And in the right hands, nutria is reportedly delicious. Some hunters in the film even say it’s preferable to steak.

Rodents of an Unusual Size makes its Los Angeles debut on September 14. To find a screening near you, check out the film’s website.

All images courtesy Rodents of Unusual Size/Tilapia Film

9 Not-So-Pesky Facts About Termites

iStock.com/Thithawat_s
iStock.com/Thithawat_s

Termites get a lot of hate for chewing through buildings, but the little creatures are far more interesting—and ecologically valuable—than we often give them credit for. Unless, of course, you’re Lisa Margonelli, the author of Underbug: An Obsessive Tale of Termites and Terminology, a new book that explores their amazing world. Here are nine facts about the highly social—and occasionally pesky—insects that we learned from the book.

1. THERE ARE FAR MORE TERMITES THAN PEOPLE ON EARTH.

Termite queens live up to 25 years, and can lay somewhere around 30,000 eggs a day. As a result, a single mound can be home to millions of individuals at a time. While the numbers vary from study to study, scientists estimate that the biomass of all the termites in the world is at least as great as that of humans.

2. MOST TERMITES AREN’T PESTS.

Of the 2800 named termite species in the world, the majority have no interest in eating your house. Only 28 species are known to chow down on buildings and infrastructure. Most are actually very beneficial to their ecosystems, clearing dead wood, aerating the soil with their intricate tunnel systems, and enhancing plant growth. Researchers have found that contrary to being pests, networks of termite mounds can help make dry environments like savannas more resilient to climate change because of the way termite mounds store nutrients and moisture, among other benefits.

3. TERMITES ARE GOOD FOR CROPS.

Termites can help make soil more fertile. In one study, researchers in Australia found that fields that were home to ants and termites produced 36 percent more wheat, without fertilizer, compared to non-termite fields. Why? Termites help fertilize the soil naturally—their poop, which they use to plaster their tunnels, is full of nitrogen. Their intricate system of underground tunnels also helps rainfall penetrate the soil more deeply, which reduces the amount of moisture that evaporates from the dirt and makes it more likely that the water can be taken up by plants.

4. TERMITES HAVE VERY SPECIFIC ROLES IN THEIR COLONY.

Each termite colony has a queen and king termite (or several), plus workers and soldiers. This caste system, controlled by pheromones produced by the reigning queen, determines not just what different termites do in the colony but how they look. Queens and kings develop wings that, when they’re sexually mature, they use to fly away from their original nest to reproduce and start their own colony. Once they land at the site of their new colony, queens and kings snap off these wings, since they’ll spend the rest of their lives underground. Queens are also physically much larger than other castes: The largest type of termite, an African species called Macrotermes bellicosus, produces queens up to 4 inches long.

Unlike their royal counterparts, most workers and soldiers don’t have either eyes or wings. Worker termites, which are responsible for foraging, building tunnels, and feeding the other castes in the nest, are significantly smaller than queens. M. bellicosus workers, for instance, measure around 0.14 inches. Soldier termites are slightly bigger than workers, with large, sharp mandibles designed to slice up ants and other enemies that might invade the nest.

5. TERMITES ARE ONE OF THE FASTEST ANIMALS IN THE WORLD.

Apologies to cheetahs, but termites hold the record for world’s fastest animal movement. Panamanian termites can clap their mandibles shut at 157 miles per hour. (Compare that to the cheetah’s run, which tops out at about 76 miles per hour.) This quick action allows tiny termite soldiers in narrow tunnels to kill invaders with a single bite.

6. TERMITES ARE SKILLED ARCHITECTS.

In Namibia, quarter-inch-long termites of the genus Macrotermes can move 364 pounds of dirt and 3300 pounds of water each year total in the course of building their 17-foot-tall mounds. Relative to their size, that’s the equivalent of humans building the 163 floors of Dubai’s Burj Khalifa, no cranes required. And that’s not even the tallest termite mound around—some can be up to 30 feet high. More impressively, termites cooperate to build these structures without any sort of centralized plan. Engineers are now trying to replicate this decentralized swarm intelligence to build robots that could erect buildings in a similar fashion.

7. TERMITES BUILD THEIR OWN AIR CONDITIONING.

Some termites have developed an incredibly efficient method of climate control in the form of tall, above-ground mounds that sit above their nests. Organized around a central chimney, the structures essentially act as giant lungs, "breathing" air in and out as the temperature outside changes in relation to the temperature inside. Thanks to these convection cycles, termites keep underground temperatures in their nest between roughly 84°F and 90°F.

8. TERMITES ARE FARMERS.

Humans aren’t the only ones cultivating crops. Termites farm, too. They’ve been doing it for more than 25 million years, compared to humans’ 23,000 years. Some species of termite have evolved a symbiotic relationship with Termitomyces fungi, growing fungus in underground gardens for food. When they fly off to create a new colony, termite queens bring along fungus spores from their parent colony to seed the garden that will feed their new nest. Foraging termite workers go out and eat plant material that they can’t fully digest on their own, then deposit their feces on the fungus for it to feed on. They can then eat the fungus. They may also be able to eat some of the plant material after the fungus has sufficiently broken it down. The mutually beneficial relationship has led some scientists to suggest that the fungus, which is much larger in both size and energy production than the termites, could in fact be the one in control of the relationship, potentially releasing chemical pheromones that lead the termites to build the mound they live in together.

9. TERMITES ARE MICROBIAL GOLD MINES.

As scientists begin to understand the huge role that micobiomes play in both the human body and the rest of the world, termites provide a fascinating case study. About 90 percent of the organisms in termite guts aren’t found anywhere else on Earth. In their hindgut alone, they host as many as 1400 species of bacteria. These microbes are so efficient at converting the cellulose-rich wood and dead grass that termites eat into energy, scientists want to harness them to make biofuel from plants.

Want to learn more about termites? Get yourself a copy of Underbug on Amazon for $18.

How the Los Angeles Zoo Protects Its Animals During Wildfires and Other Emergencies

iStock.com/Kirkikis
iStock.com/Kirkikis

It’s hard enough to evacuate a family of three when disaster strikes, let alone large groups of frightened animals. However, many zoos have detailed emergency plans in place, and the Los Angeles Zoo—home to more than 1400 animals—is no exception. As Smithsonian reports, the zoo had to evacuate some of its birds and smaller primates last week when nearby Griffith Park caught fire, all while other wildfires continued to destroy large swathes of land around the state of California.

Firefighters spent over seven hours working to extinguish the blaze, which ignited in a hard-to-reach area of the park. Meanwhile, zoo staff herded lemurs and show birds into cages with other small animals in order to evacuate them. According to statements made by the zoo on social media, no animals were harmed by the smoke, and those animals have since returned to their regular habitats.

Fortunately, this incident was contained and no fire ever entered zoo grounds, but staff are prepared for worst-case scenarios. LA Zoo employees know which animals to evacuate and which ones to shelter in place during emergencies.

“Smaller, non-venomous reptiles and mammals that can be easily handled may be packed up for relocation,” a zoo spokesperson told Smithsonian. “Larger animals will be sheltered in place in their night quarters for a variety of reasons that ultimately depend on the specific animal and the situation.”

The Santa Barbara Zoo also has species-specific emergency plans in place. According to an NPR article from 2017, when a nearby wildfire raised alarm and prompted small-scale evacuations, the zoo reviewed its plans for protecting 500 animals from disaster. Zoo staff members said some animals—like two elderly elephants, 50 “fragile” flamingos, and giraffes that were too tall to fit under highway underpasses—would have to stay put. Other animals would be trapped, placed in crates, and transported to safer locations. Big cats would need to be tranquilized (by hand, not by dart gun) before being moved into steel evacuation crates.

A few animals were evacuated at the time, including two reindeer, a baby anteater, and hard-to-catch condors. Some animals are harder to trap than others, and Chinese alligators are surprisingly easy to round up. "They usually just throw a towel over her head so she can't see them and they just jump on her," Dr. Julie Barnes, director of Animal Care and Health at the Santa Barbara Zoo, told NPR last year.

In addition to these plans, zoos also have extinguishers and fire breaks placed strategically throughout the grounds, and many staff are trained in proper evacuation procedures.

[h/t Smithsonian]

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