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

Chimpanzees Bond by Watching Movies Together, Too

Windzepher/iStock via Getty Images
Windzepher/iStock via Getty Images

Scientists at the Wolfgang Kohler Primate Research Center in Germany recently discovered that, like humans, chimpanzees bond when they watch movies together, the BBC reports.

In the study, published in Proceedings of the Royal Society B, researchers stationed pairs of chimpanzees in front of screens that showed a video of a family of chimps playing with a young chimp. They found that afterward, the chimps would spend more time grooming and interacting with each other—or simply being in the same part of the room—than they would without having watched the video.

They gave the chimps fruit juice to keep them calm and occupied while they viewed the video, and they chose a subject that chimps have previously proven to be most interested in: other chimps. They also used eye trackers to ensure the chimps were actually watching the video. If you’ve ever watched a movie with friends, you might notice similarities between the chimps’ experience and your own. Drinks (and snacks) also keep us calm and occupied while we watch, and we like to watch movies about other humans. Since this study only showed that chimps bond over programs about their own species, we don’t know if it would work the same way if they watched something completely unrelated to them, like humans do—say, The Lion King.

Bonding through shared experiences was thought to be one of the traits that make us uniquely human, and some researchers have argued that other species don’t have the psychological mechanisms to realize that they’re even sharing an experience with another. This study suggests that social activities for apes don’t just serve utilitarian purposes like traveling together for safety, and that they’re capable of a more human-like social closeness.

The part that is uniquely human about this study is the fact that they were studying the effect of a screen, as opposed to something less man-made. The chimps in question have participated in other studies, so they may be more accustomed to that technology than wild apes. But the study demonstrates that we’re not the only species capable of social interaction for the sake of social interaction.

[h/t BBC]

10 Facts You Should Know About Mosquitoes

tskstock/iStock via Getty Images
tskstock/iStock via Getty Images

Between the itching and the welts and the fears of mosquito-borne viruses, it's easy to forget that mosquitoes are a wonder of evolution, and that maybe they don't get a fair shake from us. Of more than 3000 known species, only 80 actually bite people, and at least one eats other mosquitoes for us. They grow from egg to adult in just five days, begin mating within minutes of hatching, and possess, by way of their stinging mouthparts, some of the coolest appendages in the animal kingdom.

1. Mosquitoes are excellent flyers in bad weather.

The average raindrop is 50 times heavier than the average mosquito, yet they buzz around in the rain with no problems. If a Boeing 747 got whacked with a similarly scaled-up raindrop, there would be 2375 tons of water coming down on it, and things probably wouldn’t turn out as well as they do for the mosquito. How do the insects do it?

A common urban legend said that the bugs were nimble enough to dodge the drops. A few years ago, a team of engineers from the Georgia Institute of Technology watched real mosquitoes and Styrofoam dummy mosquitoes with a high-speed camera during a rainy flight to see if that’s what was really happening. They found that the bugs don’t fly fast enough to dodge the drops, but their slowness is what keeps them from getting knocked out of the sky. A mosquito’s low mass even at slow speed doesn’t provide enough of a target for a raindrop to splash on collision. Instead, the drop just deforms, and doesn’t transfer enough momentum to the mosquito to disrupt its flight.

2. Texas is the mosquito capital of America.

Of the 3000 species of mosquitoes around the world, at least 150 are found in the United States, and 85 of those call Texas home. When people say everything's bigger in Texas, you can also include the biodiversity of the state's biting, disease-carrying insects.

3. Some mosquitoes are truly dangerous to humans ...

The female mosquito, which is the one that stings and sucks blood, is an incredible transmitter of disease and, because of that, the deadliest animal in the world. Each year, the malaria parasites they transmit kill 2 million to 3 million people and infect another 200 million or more. They also spread pathogens that cause yellow fever, dengue fever, Rift Valley fever, Chikungunya and West Nile disease.

4. ... and some mosquitoes are harmless.

Not every species of mosquito sucks blood from people, and among those that do, not every one transmits disease. The blood suckers don’t even need to bite you for every meal. Males live entirely on nectar and other plant fluids, and the females’ diet is primarily plant-based, too. Most of the time, they only go after people when they’re ready to reproduce, because blood contains lipids, proteins, and other nutrients needed for the production of eggs.

5. MosquitoEs actually help the environment.

When you’re rubbing calamine lotion all over yourself, mosquitoes might not seem to serve any purpose but to annoy you, but many species play important ecological roles. The mosquitoes Aedes impiger and Aedes nigripes, which gather in thick clouds in Arctic Russia and Canada, are an important food source for migrating birds. Farther south, birds, insects, spiders, salamanders, lizards, frogs, and fish also eat different mosquito species regularly. Plants need them, too, and some, like the blunt-leaved orchid and endangered monkeyface orchid, rely on mosquitoes as their primary pollinator.

Some mosquito species are also excellent at mosquito control. Species of the genus Toxorhynchites feed on the larvae and immature stages of other mosquitoes and will sometimes even cannibalize members of their own species.

6. Mosquitoes are amazing hunters (as if we needed to tell you that).

Mosquitoes are adept at picking up on the chemicals given off by their human hosts. They can detect the carbon dioxide in our breath, the 1-octen-3-ol in our breath and sweat, and other organic substances we produce with the 70-plus types of odor and chemical receptors in their antennae. These receptors can pick up traces of chemicals from hundreds of feet away, and once the mosquito closes in, it tracks its meal chemically and also visually—and they’re fond of people wearing dark colors.

7. Mosquitoes can be picky.

If it seems like you’re always covered head to toe by bites while people who were sitting right next to you only have one or two, it’s not just paranoia; the skeeters actually are out to get you. Some people happen to give off more of the odors and compounds that mosquitoes find simply irresistible, while others emit less of those and more of the compounds that make them unattractive to mosquitoes—either by acting as repellents or by masking the compounds that mosquitoes would find attractive.

8. A female mosquito's mouth is primed for sucking blood.

A mosquito doesn’t simply sink its proboscis into your skin and start sucking. What you see sticking out of a mosquito’s face is the labium, which sheaths the mouthparts that really do all the work. The labium bends back when a mosquito bites, allowing these other parts to pass through its tip and do their thing. The sharp, pointed mandibles and maxillae, which both come in pairs, are used to pierce the skin, and the hollow hypopharynx and the labrum are used to deliver saliva and draw blood, respectively.

9. Mosquito saliva prevents blood clotting.

The saliva that gets pumped out from the hypopharynx during a bite is necessary to get around our blood’s tendency to clot. It contains a grab bag of chemicals that suppress vascular constriction, blood clotting and platelet aggregation, keeping our blood from clogging up the mosquitoes' labrum and ruining their meal.

10. Mosquitoes can explode.

Blood pressure makes a mosquito's meal easier by helping to fill its stomach faster, but urban legend says it can also lead to their doom. Story goes, you can flex a muscle close to the bite site or stretch your skin taut so the mosquito can’t pull out its proboscis and your blood pressure will fill the bug until it bursts. The consensus among entomologists seems to be that this is bunk, but there is a more complicated way of blowing the bugs up. To make a blood bomb, you’ve got to sever the mosquito’s ventral nerve cord, which transmits information about satiety. When it's cut, the cord can’t tell the mosquito’s brain that its stomach is full, so it’ll keep feeding until it reaches critical mass. At least one researcher found that mosquitoes clueless about how full they were would keep sucking even after their guts had exploded, sending showers of blood spilling out of their blown-out back end.

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