Weird Ways We’ve Fought Invasive Species

Weird Ways We’ve Fought Invasive Species


[♪ INTRO] In a world that’s as connected as ours, it’s no wonder that species sometimes end
up in habitats that aren’t their own. But these invasive species can cause serious
trouble. They often compete with native species for
food, steal their homes, nom on them for lunch, or otherwise wreak
havoc in their new habitats. The survival of entire ecosystems can depend
on getting rid of them. But that’s not so easy. Without predators to keep them in check, invasive
species tend to stick around and multiply, despite our best efforts to fend them off. That means that we have to get pretty creative
to have any hope of eradicating them. And in some cases, humans have risen to the
challenge. Here are five of the strangest ways that people
have fought back against invasive species. The brown tree snake invaded the tiny island
of Guam in the 1940s, after stowing away on a U.S. military plane
coming from another Pacific island. Since then, the snake population, which is
now about two million strong, has eaten its way through the island, devastating
the local ecosystem. The snakes have hunted ten of Guam’s twelve
native birds to extinction. Without birds, the spider population has gone
unchecked. Forests have also thinned because there aren’t
enough birds to spread seeds. To make matters worse, since these tree snakes
live in trees, it’s tough to weed them out with traditional
methods like traps or snake-sniffing dogs. So to try to eradicate these predators, the U.S. government has been experimenting
with a more creative solution: air-dropping dead mice filled with acetaminophen, the active ingredient in Tylenol, over the
jungles of Guam. The mice come sailing down in little parachutes,
which is kind of tragically adorable. Then the parachutes get stuck in trees and dangle the mice in places where snakes
can find and eat them. And the method is pretty deadly. A year-2000 study by the National Wildlife
Research Center found that 100% of brown tree snakes die after ingesting
acetaminophen. Unlike in humans, this medicine prevents the
snakes’ blood cells from carrying oxygen. Just 80 milligrams of the stuff, about a child’s
dose of Tylenol, makes the snake go into a coma and die within
60 hours. Dead mice seem to work really well as a vessel
for the poison, because they attract the brown tree snake
but not Guam’s native species, according to a preliminary study. And so far, research suggests that this approach
is pretty effective. One study looked at a site where two rounds
of poison-mice had been dropped at different times. The researchers found a 40% decrease in the
number of baits eaten after the first round, suggesting that there were fewer snakes to
eat them by round two. So this method could go a long way in clearing
these invasive predators out of the island. While the brown tree snake snuck its way into
its co-opted home, many invasive species waltz into foreign environments
as pets. That’s probably how the spiky, colorful
lionfish got from its native Indo-Pacific seas to the
Atlantic Ocean. Lionfish have been terrorizing the Atlantic
since the late 1980s, taking over reefs, shipwrecks, and other places. It seems likely that these invaders started
out as pets whose owners dumped them in the ocean when
they didn’t want them anymore. Which sounds nice and humane! Except, these fun, zany-looking fish are actually
fierce predators. They eat mostly fish and are super-venomous, so they don’t really have predators in their
foreign territory, which makes them pretty much unstoppable. Lionfish have drastically reduced the populations
of fish where they live. And it doesn’t stop there. Lionfish devour other fish that typically
eat algae, and unchecked algae growth crowds out coral
reefs. So lionfish are indirectly killing our reefs. That’s a pretty serious problem. But it’s not like we can just fish them
out of the ocean. Lionfish have been moving into deeper and
deeper waters, making them hard to catch with a hook and
bait. That depth poses another problem, too: it gets too risky for divers to catch a fish
with, say, nets because the water pressure gets dangerously
high. So, to stave off the lionfish invasion, the
the CEO of iRobot, which made the Roomba, yeah, that little robot
vacuum, has developed human-controlled, pressure-resistant
robots that can go where humans can’t. Deep underwater, the goal is for these weird
tube robots to track down lionfish, give them a good zap to stun them, and then
suck them up with a vacuum. The good news is lionfish are a pretty easy
catch. Since they aren’t used to having predators
around, they don’t really run away from things that
approach them, even weird robots with little clappers attached. Which is pretty convenient for the robot. Along with clearing the water of invasive
species, this underwater robot collects lionfish that
could ultimately be served at restaurants. Lionfish actually makes a pretty tasty dish
that some people compare to snapper. As of 2019, the robot is still being refined,
so it’s not on the market yet. But its makers are perfecting the design and preparing the machine to suck the invasive
lionfish out of the seas. The lionfish isn’t the only invasive fish
that’s been hard to root out. In the Upper Missouri River Basin, brook trout
from the Eastern U.S. have been crowding out the area’s native
trout species since the 19th century, when people introduced them as a way of replenishing
fish populations around the country. In the past, people have gotten rid of invasive
fish by dumping toxic chemicals in the river to
poison them, but it probably doesn’t surprise you that
that solution leaves something to be desired. The toxins kill invasive fish and native fish
alike, including ones we rely on for food. So researchers in Montana have developed a much safer way of removing the trout without
killing everything else. The technique is called backpack electrofishing,
and it’s pretty much what it sounds like. Essentially, researchers wade into the water
wearing backpacks with electric generators. The generators are connected to wands with
positive charge flowing through them, and researchers stick them in the water. Fish are naturally programmed to swim toward
positive charge, so they approach. That’s when the scientists unleash an electric
burst that can temporarily stun hundreds of fish
in one go. The stunned fish float to the surface and
get scooped up in nets. From there, the researchers separate out the
invasives, which can become meals, and return the native fish to the water. Researchers have taken out tens of thousands
of trout from the basin with this method, and the best part is, it doesn’t hurt the
environment they’re trying to protect. It’s nice to be able to tackle invasive
species in bulk, but sometimes you just have to go one by one. That’s the case in Washington state, where invasive mountain goats are wreaking
havoc in Olympic National Park. After hunters in Alaska introduced them in
the 1920s, these goats quickly spread into their new
habitat. As of 2018, around 700 goats were roaming
the peninsula, grazing on the rare plants and eroding the
landscape as they trampled across it. Oh, and there’s another detail. The Olympic goats are addicted to human pee. Turns out pee, and human sweat,is a rare source
of salt in the park; and the goats just love it. As the goats have gotten used to humans, they’ve
also gotten aggressive. Unfortunately, getting rid of the goats is
not a walk in the park. According to the National Park Service, typical approaches to invasive species won’t
cut it for all sorts of reasons. We can’t just introduce goat predators,
like wolves, because they’d happily gobble up the park’s
native animals too, like elk and deer. And we can’t just give the goats salt so
they lay off the pee, since they’d keep eating up native plants
and eroding the landscape. So the U.S. government has come up with a
solution: airlift the goats to their natural habitat
in the Cascade Mountains. To do that, they first paralyze the goats
with a dart, then blindfold them to keep them from panicking. After that, they hoist the goats up in a harness
attached to a helicopter and take them to a staging area, where a truck
picks them up and delivers them to the Cascades. And that may sound like overkill, but there
is some logic to the idea. Because of overhunting, the number of mountain
goats in the Cascades has been dwindling. Some experts believe that bringing the goats
back to their natural habitat could help the population bounce back. Not only would this forced migration add hundreds
more goats to the ecosystem, it would also increase the genetic diversity
of the goats in the region, which could ultimately help the population
thrive. When it comes to removing invasive species, it’s often the last few stragglers that
are the hardest to weed out. But if you don’t get the stragglers, the
population will likely bounce back. That was the problem on Isabela Island in
the Galapagos. Across the archipelago, goats had reduced
or completely wiped out almost 80% of plant species, which seriously
messed up the ecosystem. In 2004, helicopter crews managed to wipe
out about 90% of the goats on Isabela Island by
shooting them, but then they had to deal with the last 10
percent. Unfortunately, it can get pretty expensive
looking around for goats in a helicopter. So researchers turned to undercover goats. They captured around 800 female goats, neutered
them, and laced them with hormones that make them
seem like they’re always in heat. These chemically altered goats are called
Judas goats. Researchers then fit them with a collar so
they could track them, then released them into the wild. Since they were chemically aroused all of
the time, they sought out other goats, especially males, and scientists were able
to follow their trackers to the stragglers. They did that every few weeks, and then shot
all of the goats who weren’t Judas goats. After all the stragglers were gone, the Judas
goats, which couldn’t reproduce, were left to carry out the rest of their lives
alone. Of course, it takes a lot of resources to be able to pull off any of these creative
ways of fighting off invasive species. But even without a helicopter or an underwater
fish vacuum, you can still do things to help control invasive
species where you live, like cleaning off your shoes after hiking
or planting native plants in your garden. Even small steps like these can help keep
our ecosystems in balance. Thanks for watching this episode of SciShow! And thank you to our patrons for your support
and curiosity about the universe. You’re the reason we can keep making videos
like this one. If you’re not a patron but are interested
in supporting, head over to patreon.com/scishow. [♪ OUTRO]

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About Nicklaus Predovic

100 thoughts on “Weird Ways We’ve Fought Invasive Species

  1. I don't know, drugging a goat to make it permanently in heat feels kinda rapey.

    Now that's a sentence I never expected to write.

  2. uhm, about that mice idea…. what happens to the parachutes? I mean they have to be a lot of them. What are they made out of? Do they degrade? are they being picked up?

  3. 0:53: And let me guess, Samuel L. Jackson was on his way to vacation in Guam that day?
    2:29: Wait, couldn't that mean that the snakes were on to the people and stopped eating the poisoned mice?
    4:07: "Oh… you're approaching me?" "I can't suck you up without approaching you."

  4. Aggresive goats attracted to urine is serious problem.
    But it could be much worse, imagine this apex predator terrorizing locals while hunting for their urine …

    Bear Grylls

  5. Oh trust me, Americans manage to screw the dead drug mice on trees thing. Soon you guys notice how it has actually killed a lot of other predatory creatures that already used to live there. America never really looks into things more carefully with long term thinking. Could at least stop all the war waging but Trump…

  6. …So, as a solution to invasive lionfish spreading to where we can't get them, the Roomba company basically just made a new kind of Roomba to suck it up?

  7. Some jackass thought it would be a good idea to bring a plant from Japan that grows absurdly fast to control erosion in places called Kudzu. Can grow up to 75 feet in a season. (1 to 1.5 feet a day. Now its spread like wildfire in the areas it was introduced.

    To combat this our mayor decided to rent a whole shitload of goats and a few donkeys. They put up a pen around the area to be cleared and the donkeys guard the goats from other animals. Mainly dogs. Its cut it back a good amount however we will likely be dealing with it until the next extinction even. Its like Japanese plant herpes.

    I think i should start a petition to rename it Japanese Plant Herpes. Seems like a really accurate description for it.

  8. It's common to use tame goats in Australia, to get rid of blackberry vines in native areas. Once established they are almost impossible to get them out. But goats will destroy blackberry infestations in days.

  9. 2:26 can't this also be because the ones that didn't eat the tree rats still didn't eat the tree rats so, and the ones that did are already dead. Maybe the paper explains in more detail but that seems like a huge assumption.

  10. We are such control freaks. To be contrarian invasion by species from outside the local ecosystem is a natural process. The Great American Interchange is a prime example of that. We have shifted things into overdrive but that does not remove it from the catagory of natural process. Our metaphors are all messed up. We always reach for the war metaphor to talk about invasive species, why not look at it as a matter of engineering rather than combat. Not all invasions are the same. Big herbivores or predators making it to isolated islands can cause drastic changes. Organisms making the jump from one bioregion to another where there isn't a history of similar organisms can cause big changes, lionfish are a fairly good example. These are not the same as mountain goats in the Olympics where they have moved 100 miles or so over land to an area with the same biota (at least at the genus level) as the place it came from.
    Restore the basic structure of an ecosystem with predators and big herbivores and trust to evolution at least in continental situations. On remote islands the choice must be made to try and go back towards what was or to go forward towards what might be.

  11. We culled feral cats in my grandma’s neighborhood by shooting them, but quickly found out that the most effective method was to leave the Coyotes, Bobcats, and Racoons alone and let nature take its course. Ecological balance, even by force, can usually do a lot of the work for us.

  12. There's an alternative way (and better way) to get rid of Lionfishes: some people are training local predators that don't really have a problem eating them with dead ones. So they just learn that this unknown animal is a prey. It seems that this is successful.
    Also scales much better. When a shark or a grouper or eel sees another one eating a lionfish I bet he does the same later

  13. 4:15 What happened to “deadly toxic” though? I swear humanity loves to eat things that’ll kill them twice over

  14. One important way to not support invasive species is to not pland English ivy if you don't live in England. The previous owner of my house planted some and its so hard to get rid of…..I rip it all out and I keeps coming bacl 😭

  15. I had lawn shrimp, invasive species from Australia. I lived in Savannah, Ga, USA. Apparently no exterminator can deal with these. They kamikazed into my home when it rained and carpeted my…carpet with their soon-desiccated corpses. No amount of portal sealing helped me, they always found a way in. After two rainy seasons, I was desperate.

    My solution: encourage and even feed my fire ants. My backyard became a fire ant apocalypse, impossible to traverse without knee-high boots.

    No more lawn shrimp.

  16. invasive species you cook them and release natives!
    The biggest problem with invasive species is the laws surrounding the capture of native species. some governments charge for permits for like fishing hunting etc this should be resolved by getting rid of the charges BUT all native species (unless its a season for capture) are released if captured and make it no limit on the invasive!

  17. The snake population control bit. I think the conclusion of the scientist might be a bit flawed if they only count rats eaten without any other data? As it is possible that the snakes most likely to eat dead mice dead and all it has done is to make the species, in the area, less likely to eat dead rats?

  18. Humans are the ultimate invasive species. Or, more specifically, certain cultures are invasive species. Some cultures, such as the nomadic Native Americans, wouldn't be, but most certainly the countries destroying the Earth for profit are an invasive species.

  19. there is a nice not so uncommon practice. eat them… in berlin there is a small restaurant turning invasive species into delicious foods. all local, all natural. like the red swamp crawfish in germany known as the american crawfish. is usualy native to nothern mexico and southern usa but really like rivers and lakes in berlin and brandenburg. its not an solution to end this whole thing but currently those crayfish and other invasive species are hunted but were not used which is simply a waste.

  20. 8:25 "The Judas Goats were left out the rest of there lives alone." Sounds good until you remember they are horny 24/7.

  21. They need to make a underwatter drone that has a shreader on the front of it like that one that can crush a bowling ball then just drive into the fish and grind it up xD.

  22. You blindfold them… to keep them from panicking? i dunno about you, but if I was that goat, I'd be long past the point of panicking.

  23. Great a new nightmare,that I would've never imagined to haunt my nightmares…Dead mice parachuting from the sky! …Hmm…New horror movie…Zombie Mice from the sky! 😉

  24. Also, closer to coast, divers are trying to train Atlantic sharks (which would be their natural predator in the Indian ocean) to eat the lion fish by feeding them to them on sticks. It's pretty cute

  25. I don't know if my focus is wrong here, but this judas goat thing should be developed for humans. I mean, we really need a female viagra equivalent that isn't the credit card.

  26. Funny how only humans will consider or classify a species of life on earth to be "invasive". Birds, reptiles, sea creatures, insects, small mammals – all have been found on natural floating debris after the Japan tsunami of 2011. Many pieces floated to Hawaii and all around the Pacific and delivered species to far remote locations previously thought impossible for some of these organisms to traverse "naturally"… Nature doesn't consider any species to be invasive, only one competing for resources and subject to the local forces of survival. If it thrives, then it was meant to.. Only selfish myopic humans create borders, then presume every other organism must stay in its lane..

  27. Whenever I awake after being shot with a tranq dart I do not say to myself "It's ok, the blindfold means there's no need to panic."

  28. Drunk Scientist: "Crazy idea, but to kill these snakes we're gonna need a mice. A bunch of mice! Not alive, dead ones! And we'll fly'em in on parachutes and stuff'em all with Tylenol!"

  29. Poor goats. Hundreds of perma-heat females with not a single male around…
    Maybe some kind of yuri paradise for them, I guess. Well, no.

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