Name: 生き残るために人間に頼る6つの方法 (6 Ways Species Rely on Humans for Survival)
Uploaded: 2021-01-14T10:47:58.000Z
Duration: 11 min 23 s
Description: VoiceTubeの動画で発音を聞きながら英語表現を覚えよう！学べる英語：

It's not a secret that we haven't been the greatest at taking care of the planet

But thankfully, there are countless conservation efforts happening all over the world to try

When a species' population is in decline, we can try to find measures to slow — and

hopefully, reverse — whatever is going on.

But sometimes, a population has declined so dramatically that they require serious human

intervention to ensure they don't disappear forever.

That's when a species can become conservation-reliant.

This means they're in need of consistent, species-specific management in order to survive.

What exactly that looks like can vary… a lot.

Sometimes, it means directly protecting a species from whatever is threatening its survival,

like invasive predators or a toxin in their habitat.

Other times, it means that a species can only survive in human-run breeding programs and

may never be able to live in the wild again.

The reasons a species becomes conservation-reliant are often our fault, but at least we're

So, here are six ways a species can become conservation-reliant, and some of the strategies

Sometimes, when a compound is introduced to the environment, it has a dramatic and often

These condors are iconic scavengers and are the largest wild birds in North America.

But they've also become severely endangered due to lead poisoning.

This happens as condors ingest ammunition fragments in the carcasses they feed on, and

At one time, the total condor population was as low as 22 individuals!

Thankfully, in the 1980s, people did start captive breeding programs to boost those numbers,

and today, all 400 or so living condors are descended from those birds.

Even after all these years of aggressive management, their population is still completely dependent

on the repeated release of captive-bred condors.

Part of that is because these birds reproduce very slowly.

They only lay an egg every 1-2 years, so infertile ones can have a significant impact.

To help with this and keep wild pairs nesting successfully, biologists have put their rock-climbing

skills to work, visiting condor nests on cliff faces to swap out any infertile eggs with

The bigger problem, though, is that these animals are still being poisoned.

Wild birds have to be screened for lead poisoning each year, and then treated if there's enough

Scientists are hoping this won't have to go on forever, though.

Their goal is to establish self-sustaining wild populations in the future, and to use

education programs to reduce the risk of lead poisoning.

The world is becoming a more interconnected place all the time.

And while that's great for a lot of reasons, it also means things like disease spread much

There's a long list of species that have become conservation-reliant because new diseases

And one of them is the Panamanian golden frog.

This frog is Panama's national animal, and it packs a toxic punch so powerful that one

individual contains enough toxin to kill 1200 mice.

It was once found near forest streams along the slopes of Panama, but the spread of the

fungal disease chytridiomycosis has now wiped out the entire wild population.

It causes microscopic changes in amphibians' skin so that it becomes really thick.

And since amphibians absorb water and salts through their skin — and sometimes even

breathe through it — this typically causes heart failure or suffocation.

In 2018, research published in the journal Science revealed that the deadly strain of

this fungus originated in East Asia, and likely spread to Panama through the global amphibian

So, yeah, this one is probably our fault, too.

As far as we know, these frogs now only exist in managed breeding facilities and zoos, but

researchers have been working on ways to protect future frogs if they're ever reintroduced

they've investigated beneficial bacteria, probiotics with antifungal properties, and

gene expression in captive-bred populations.

They're even perfecting techniques to extract and freeze the frogs' sperm, to hopefully

add some genetic diversity into their gene pool.

Although the future is very uncertain for the Panamanian golden frog, this research

could greatly benefit other amphibian species, too.

Because it's not just the golden frog that's in such dire straits.

This fungus is known to infect hundreds of frog and salamander species across the globe,

and with so many of the world's amphibians are already threatened with extinction, protecting

them from the chytrid fungus is critical to their survival.

Many of these species are supported by a group called the Amphibian Ark, which supports amphibian-care

But ultimately, that's a lot of species to take care of.

So the sooner we can get them back to the wild, the better.

Sometimes, multiple factors are at play in a species' decline, and their conservation-reliance

That's the case with one of the world's most famous shelled animals: the Galápagos

First, these gentle giants were dramatically overharvested in the 17- and 1800s, mostly

So at least one species was already extinct before conservation efforts were even considered.

Then, even after we stopped eating the tortoises, the threats didn't go away, because they

still had to deal with a bunch of invasive species.

Whether it's accidental or not, we humans have a bad habit of bringing species to places

These invasives can displace native plants and animals, can outcompete them, or can alter

Or, in the case of the poor Galápagos tortoises, all of these things can be true.

For example, black rats were introduced to the Galápagos Islands in the late 1800s,

and they've been eating tortoise eggs and babies ever since.

Then, goats were brought there and dramatically changed the vegetation the tortoises depend

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生き残るために人間に頼る6つの方法 (6 Ways Species Rely on Humans for Survival)

eventually

eliminate

thrive

impact