Joshua Powell, UCLThe return of wolves to Yellowstone National Park in 1995 popularised the idea of reintroducing long-lost species to modern habitats. While scientists are still trying to fully understand the ecological consequences, the wolf’s reintroduction likely benefited other species, illustrating how conservation can not just slow biodiversity loss, but even reverse it.
That project, however, took place in a vast protected wilderness. Many of the places where biologists now hope to reintroduce large wild animals – whether it’s lynx in Britain or cheetahs in India – are a little closer to where people live, with all of the potential problems that entails in terms of human-wildlife conflict.
In South Korea, a country of similar size and similar human population density to England, conservationists are in the process of restoring the native bear population, Asiatic black bears, or moon bears, to be precise. While slightly smaller than their North American cousins, these are still large wild animals, capable of causing fear and alarm and posing a risk to human life and property.
I wanted to find out how South Korea is managing this ambitious project, so I travelled to Jirisan National Park, a mountainous region in the far south of the Korean Peninsula.
By the 1990s, along with occasional sightings in the Demilitarised Zone (DMZ), Jirisan had become the last foothold of the Asiatic black bear in South Korea. An attempted eradication programme by the colonial Japanese regime of the early 20th century and overhunting following independence in 1945 meant bears had fared badly for some time. At the close of the century, there were thought to be just five wild bears left in the country, and the species was on the brink of extinction in South Korea.
These were not the only bears in the country though. A large population lingered on farms producing bear bile and body parts, which are used in traditional medicine, and bear meat. Since the 1990s, South Korea has cracked down on the bear part trade, but the remaining population of around 380 captive bears still substantially outnumbers those in the wild (around 70 in 2021).
These farm bears might have seemed the ideal animals to rebuild a wild population. But the bears probably belonged to a range of different subspecies and were potential disease risks. Years of being fed by humans also meant that the bears could seek out contact – and cause conflict – with humans. Instead, bears were imported from China, Russia and North Korea. In 2004, the first six cubs were released into Jirisan.
Why did South Korea’s bear programme succeed?
No grand claims were made about reshaping the relationship between humans and the natural world, and no changes were promised to centuries-old methods of managing landscapes, ideas which often feature in debates about rewilding. Instead, conservationists in South Korea established a modest initial goal: returning a population of 50 bears to a single protected area.
Soft releases, in which bears are kept in pens to acclimate to their surroundings before being set free, and extensive monitoring of bears post-release, helped increase the likelihood of each released bear surviving. Bears that strayed too far were returned to the national park.
Captive breeding, underpinned by impressive veterinary expertise, has also helped the population grow. One milestone involved the world’s first successful use of artificial insemination in this genus of bear, a boon for maintaining genetic diversity in a small population. Bears injured by snares or traffic collisions have also been successfully returned to the wild.
The initial target of 50 bears was exceeded and the population now stands at over 70. A recent study found that some bears were now dispersing across South Korea, suggesting that Jirisan National Park may be close to reaching the limit of bears it can sustain.
This presents new challenges. Conservationists have, so far, been remarkably successful at reducing conflict between bears and people, and building support for restoring bears to Jirisan National Park with education programmes, presentations for residents and hikers, a centre where visitors can learn about the reintroduction programme and even the use of moon bear mascots for the 2018 Pyeongchang Winter Paralympics.
But the appearance of bears outside of the national park still attracts prime-time media coverage, which can hamper efforts to cultivate tolerance and maintain a reasonable dialogue with the public about the realities of living alongside bears. People feeding bears remains an issue, as does illegal snaring for game species, which can severely injure bears. As South Korea reaches the next stage of its reintroduction programme, is the country prepared to accept bears outside of a protected area?
It will be fascinating to follow these bears over the coming years as conservationists address these questions. And Asiatic black bears are just the start. South Korea has since established programmes to restore the red fox, which is surprisingly rare in the country, and the long-tailed goral, a goat-like mammal whose populations have been depleted by poaching and habitat loss.
These programmes will face challenges, but South Korea has shown considerable expertise in the field of mammal reintroductions. Expertise that other countries could well learn from.
Nicky Wright, University of Sydney; Andréa S. Taschetto, UNSW, and Andrew King, The University of MelbourneThis month we’ve seen some crazy, devastating weather. Perth recorded its wettest July in decades, with 18 straight days of relentless rain. Overseas, parts of Europe and China have endured extensive flooding, with hundreds of lives lost and hundreds of thousands of people evacuated.
And last week, Australia’s Bureau of Meteorology officially declared there is a negative Indian Ocean Dipole — the first negative event in five years — known for bringing wet weather.
But what even is the Indian Ocean Dipole, and does it matter? Is it to blame for these events?
What is the Indian Ocean Dipole?
The Indian Ocean Dipole, or IOD, is a natural climate phenomenon that influences rainfall patterns around the Indian Ocean, including Australia. It’s brought about by the interactions between the currents along the sea surface and atmospheric circulation.
It can be thought of as the Indian Ocean’s cousin of the better known El Niño and La Niña in the Pacific. Essentially, for most of Australia, El Niño brings dry weather, while La Niña brings wet weather. The IOD has the same impact through its positive and negative phases, respectively.
Positive IODs are associated with an increased chance for dry weather in southern and southeast Australia. The devastating Black Summer bushfires in 2019–20 were linked to an extreme positive IOD, as well as human-caused climate change which exacerbated these conditions.
Negative IODs tend to be less frequent and not as strong as positive IOD events, but can still bring severe climate conditions, such as heavy rainfall and flooding, to parts of Australia.
The IOD is determined by the differences in sea surface temperature on either side of the Indian Ocean.
During a negative phase, waters in the eastern Indian Ocean (near Indonesia) are warmer than normal, and the western Indian Ocean (near Africa) are cooler than normal.
Explainer: El Niño and La Niña
This causes more moisture-filled air to flow towards Australia, favouring wind pattern changes in a way that promotes more rainfall to southern parts of Australia. This includes parts of Western Australia, South Australia, Victoria, NSW and the ACT.
Generally, IOD events start in late autumn or winter, and can last until the end of spring — abruptly ending with the onset of the northern Australian monsoon.
Why should we care?
We probably have a wet few months ahead of us.
The negative IOD means the southern regions of Australia are likely to have a wet winter and spring. Indeed, the seasonal outlook indicates above average rainfall for much of the country in the next three months.
In southern Australia, a negative IOD also means we’re more likely to get cooler daytime temperatures and warmer nights. But just because we’re more likely to have a wetter few months doesn’t mean we necessarily will — every negative IOD event is different.
While the prospect of even more rain might dampen some spirits, there are reasons to be happy about this.
First of all, winter rainfall is typically good for farmers growing crops such as grain, and previous negative IOD years have come with record-breaking crop production.
Negative IOD years can also bring better snow seasons for Australians. However, the warming trend from human-caused climate change means this signal isn’t as clear as it was in the past.
It’s not all good news
This is the first official negative IOD event since 2016, a year that saw one of the strongest negative IOD events on record. It resulted in Australia’s second wettest winter on record and flooding in parts of NSW, Victoria, and South Australia.
Thankfully, current forecasts indicate the negative IOD will be a little milder this time, so we hopefully won’t see any devastating events.
Is the negative IOD behind the recent wet weather?
It’s too early to tell, but most likely not.
Negative IODs tend to be associated with moist air flow and lower atmospheric pressure further north and east than Perth, such as Geraldton to Port Hedland.
Outside of Australia, there has been extensive flooding in China and across Germany, Belgium, and The Netherlands.
It’s still early days and more research is needed, but these events look like they might be linked to the Northern Hemisphere’s atmospheric jet stream, rather than the negative IOD.
The jet stream is like a narrow river of strong winds high up in the atmosphere, formed when cool and hot air meet. Changes in this jet stream can lead to extreme weather.
What about climate change?
The IOD — as well as El Niño and La Niña — are natural climate phenomena, and have been occurring for thousands of years, before humans started burning fossil fuels. But that doesn’t mean climate change today isn’t having an effect on the IOD.
Scientific research is showing positive IODs — linked to drier conditions in eastern Australia — have become more common. And this is linked to human-caused climate change influencing ocean temperatures.
Climate models also suggest we may experience more positive IOD events in future, including increased chances of bushfires and drought in Australia, and fewer negative IOD events. This may mean we experience more droughts and less “drought-breaking” rains, but the jury’s still out.
When it comes to the recent, devastating floods overseas, scientists are still assessing how much of a role climate change played.
But in any case, we do know one thing for sure: rising global temperatures from climate change will cause more frequent and severe extreme events, including the short-duration heavy rainfalls associated with flooding, and heatwaves.
To avoid worse disasters in our future, we need to cut emissions drastically and urgently.