{♫Intro♫}.

It's not a secret that we haven't been the greatest at taking care of the planet we live and depend on. But thankfully, there are countless conservation efforts happening all over the world to try and undo some of that damage.

Because, y'know, better late than never. 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 stepping up to care for them.

So, here are six ways a species can become conservation-reliant, and some of the strategies we're using to keep those species alive. Sometimes, when a compound is introduced to the environment, it has a dramatic and often completely unintended effect. Take the story of the California condor.

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 it's a major problem.

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. But their story isn't over.

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 fertile ones from captive-bred birds. 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 lead in their bloodstream.

Which requires a lot of time and energy. 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 more easily. There's a long list of species that have become conservation-reliant because new diseases were introduced to their environment.

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.

The chytrid fungus is a serious killer. 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 trade. 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 to the wild.

Their work is incredibly complex, and 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 efforts around the world.

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 hinges on more than one threat.

That's the case with one of the world's most famous shelled animals: the Galápagos tortoises. First, these gentle giants were dramatically overharvested in the 17- and 1800s, mostly for food or oil. 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 they don't belong. These invasives can displace native plants and animals, can outcompete them, or can alter their new environments.

They can also become a predatory threat. 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 on. Eventually, pigs were introduced and started feeding on nestlings and eggs — and the list just kept growing. Today, the tortoises also have to deal with an invasive ant that attacks hatchlings, and even invasive blackberries that prevent them from reaching food and breeding sites.

We really messed up those islands, friends. As a result of all this, tortoise breeding programs are required to repopulate the islands, and in some cases, they're the only way the animals can reach adulthood without getting eaten. So far, these programs have been successful — but even better, we've also been able to deal with some of those invasives.

By 2006, goats were eliminated from several of the islands, and black rats were eradicated from Pinzón Island in 2012. Then, two years later, wild-bred tortoise hatchlings were seen on the island for the first time in a century! That said, eradicating invasive predators from all islands may not be possible, especially with the larger ones.

But there's still a lot of hope. For the most part, we don't want other species to become reliant on us. We want them to survive and thrive all by their bad selves.

But sometimes, the needs of a species don't overlap with what people want. And while it's a hotly-debated topic, fire suppression is a key example of that. Fires are a normal part of nature, and certain ecosystems rely on them to control forest growth.

The problem is, those forests are often close to areas where people live, so they get suppressed or otherwise prevented. And the species that rely on them tend to suffer — like the Karner blue butterfly. It was once found abundantly across 12 U.

S. states and one Canadian province, but in the last 15 years or so, the population has dropped by 99%. That's because Karner blue caterpillars only feed on one type of plant: the wild lupine. And to thrive, the lupine needs fire.

More specifically, it needs fires to open up forest canopies and allow sunlight to reach the ground. Otherwise, it will be out-competed by pines, oaks, and shrubby vegetation. To get around this, scientists and land managers are working together to use intentional, smaller, prescribed fires to mimic what the wild lupine needs, and to protect species like the Karner blue butterfly.

Like other conservation methods, it's something that takes a lot of time and effort, but many people argue it's the best option. Finally, sometimes the loss of one species means the demise of another. This was true for a cliff-dwelling plant species commonly known as alula — although it's also called Cabbage on a Stick because, well, look at it.

This plant is endemic only to the Hawai'ian islands of Kaua'i and Ni'ihau. And unfortunately, its pollinator likely disappeared before we were even sure what it was. Based on the plant's flower shape, color, and size, we now think it was likely a kind of long-tongued moth.

But regardless, it seems to be gone now. This means that the alula can no longer breed in the wild on its own, so scientists had to step in and help. Of course, these plants do live on cliffs, so this was an extra special kind of rescue.

In the beginning, dedicated conservationists with mad skills had to rappel down steep cliffs to manually transfer pollen between plants. Just in case you thought biologists weren't hardcore. Once the plants produced fruit, they were collected so that the seeds could be grown and cared for in greenhouses.

The plants haven't been found on Ni'ihau since the 1940s, and although there was a population in Kaua'i, storms wiped it out in the ‘80s and ‘90s. Right now, there is only one known wild plant remaining. That being said, conservation efforts made the plants quite popular in greenhouses and nurseries around the world, so they're still out there.

And the hope is that, eventually, they can be planted in the wild again. But without a pollinator, this species looks to be heavily conservation-dependent for the foreseeable future. Sadly, in many of these cases, the damage has already been done, and some of these species may never thrive without human intervention.

But intensive conservation programs are preventing them from disappearing forever, and many researchers are hopeful that they'll be able to get their species back into the wild. Either way, one thing is for sure: One of the most important factors when it comes to protecting the world's biodiversity is just understanding the impact we're having. So as we keep learning and teaching each other, maybe we'll stop some future problems before they start.

This episode of SciShow is brought to you by our patrons on Patreon — so if you're a patron, thank you! We couldn't do all of this research and production stuff without your support, and your generosity makes a huge difference. If you want to help us keep making free online content like this, you can go to patreon.com/scishow. {♫Outro♫}.