Monks Wood Wilderness: 60 years ago, scientists let a farm field rewild – here’s what happened

UK Centre for Ecology & Hydrology, Author provided

Richard K Broughton, University of OxfordIn the archive of the UK Centre for Ecology & Hydrology there is a typed note from the 1960s that planted the seed of an idea.

Written by Kenneth Mellanby, director of the Monks Wood Experimental Station, a former research centre in Cambridgeshire, UK, the note describes a four-hectare arable field that lies next to the station and the ancient woodland of the Monks Wood National Nature Reserve. After harvesting a final barley crop, the field was ploughed and then abandoned in 1961.

The note reads:

It might be interesting to watch what happens to this area if man does not interfere. Will it become a wood again, how long will it take, which species will be in it?

So began the Monks Wood Wilderness experiment, which is now 60 years old. A rewilding study before the term existed, it shows how allowing land to naturally regenerate can expand native woodland and help tackle climate change and biodiversity loss.

The Monks Wood Wilderness field (outlined in red) shortly after abandonment in the early 1960s.
UK Centre for Ecology & Hydrology, Author provided

How new woodland generates itself

A shrubland of thorn thickets emerged after the first ten to 15 years. Dominated by bramble and hawthorn, its seeds were dropped by thrushes and other berry-eating birds. This thicket protected seedlings of wind-blown common ash and field maple, but especially English oak, whose acorns were planted by Eurasian jays (and maybe grey squirrels too) as forgotten food caches. It’s thought that jays were particularly busy in the Monks Wood Wilderness, as 52% of the trees are oaks.

Jays habitually collect and cache acorns in autumn. Forgotten caches germinate into oak seedlings.
UK Centre for Ecology & Hydrology, Author provided

The intermediate shrubland stage was a suntrap of blossom and wildflowers. Rabbits, brown hares, muntjac deer and roe deer were all common, but the protective thicket meant there was no need for fencing to prevent them eating the emerging trees. Those trees eventually rose up and closed their canopy above the thicket, which became the woodland understorey.

The result is a structurally complex woodland with multiple layers of tree and shrub vegetation, and accumulating deadwood as the habitat ages. This complexity offers niches for a wide variety of woodland wildlife, from fungi and invertebrates in the dead logs and branches, to song thrushes, garden warblers and nuthatches which nest in the ground layer, understorey and tree canopy.

The Monks Wood Wilderness in 2021, after 60 years of natural regeneration.
UK Centre for Ecology & Hydrology, Author provided

The Monks Wood experiment benefited from the field lying close to an ancient woodland, which meant an ample supply of seeds and agents for their dispersal – jays, rodents, and the wind. Such rapid colonisation of the land would be unlikely in more remote places, or where deer are superabundant.

But there are many woods in the UK that could expand by allowing adjacent fields to return to nature. This would eventually add up to a significant increase in total woodland cover.

The Monks Wood Wilderness (outlined in red) in 2014.
UK Centre for Ecology & Hydrology, Author provided

Tree planting or natural regeneration?

The UK is one of the least forested places in Europe, with just 13% forest cover compared to an average of 38% across the EU. Only half of the UK’s forest is native woodland, which sustains a wide variety of indigenous species. The rest is dominated by non-native conifer plantations grown for timber.

This situation is gradually changing. The UK government aims to create 30,000 hectares of new woodland each year until 2025, providing new habitat for wildlife and helping reach net zero emissions, as woodland stores more carbon than any other habitat except peatlands.

With the climate and biodiversity crises getting worse each day, there’s an urgent need to expand woodland fast. But how? Tree planting is the usual approach, but it’s costly. Saplings also have to be grown, transported, planted and protected with fencing and plastic tubes – that’s a lot of carbon emissions and potential plastic pollution, as tubes break down into the soil.

What about doing virtually nothing instead? Natural regeneration involves creating woodlands by allowing trees and shrubs to plant themselves under natural processes. It’s free and involves no plastic or nursery-grown saplings, which can introduce diseases. The result is woodland that’s well adapted to local conditions.

Oak seedlings were early pioneers in the regeneration of the woodland.
UK Centre for Ecology & Hydrology, Author provided

Allowing the land to naturally regenerate sounds exciting, but planners and ecologists need to know where this approach is likely to work best. How abandoned land turns into woodland is rarely documented, as it usually happens where people have walked away.

The Monks Wood Wilderness fills in this gap in our knowledge as an example of planned natural regeneration that has been monitored over decades, with a second two-hectare field (named the New Wilderness) added in 1996 to expand the experiment.

Shrubland in the New Wilderness field after 25 years, with hawthorns blossoming.
UK Centre for Ecology & Hydrology, Author provided

Since the 1990s, the two Wildernesses have been regularly surveyed by scientists counting and measuring trees on foot and tracking tree cover from planes and drones. These surveys documented the development of woodland over 60 years in our recently published study, revealing the patterns of habitat regeneration.

We can now finally answer Mellanby’s 60-year old questions. Within 40 to 50 years, the ploughed field became a closed canopy woodland with almost 400 trees per hectare. And as the canopy grows taller, more plant and animal species are arriving, such as marsh tits and purple hairstreak butterflies – mature woodland specialists that have made a home here as the habitat gradually converges with the ancient woodland nearby.

The Wilderness experiment shows what’s possible when nature is allowed to create rich, native woodland for free. I think Mellanby would be pleased with how it all turned out.

Richard K Broughton, Ecologist and Ornithologist at UK Centre for Ecology & Hydrology and Senior Research Associate in Zoology, University of Oxford

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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South Korea is bringing back bears in a country of 52 million people – I went to find out how

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.

The Asiatic black bear (Ursus thibetanus), or moon bear.
Joshua Powell, Author provided

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).

A captive Asiatic black bear on a disused bear bile farm in Gangwon-do, South Korea.
Joshua Powell, Author provided

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.

Veterinarians prepare to transport a female bear following examination.
Joshua Powell, Author provided

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?

Bukhansan National Park, near Seoul. Once home to leopards and tigers, could these mountains see bears again?
Joshua Powell, Author provided

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.

Joshua Powell, London NERC DTP PhD Researcher, UCL

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Rewild 25% of the UK for less climate change, more wildlife and a life lived closer to nature

Eduard Militaru/Unsplash, CC BY-SA

Simon Lewis, UCL

The UK’s Labour Party has pledged to offer voters a Green New Deal at the next election. This is a radical programme for decarbonising society and the economy by 2030, through phasing out fossil fuels, investing in renewable energy and creating a public works programme to build the zero-carbon infrastructure of the future.

In my recent report, A Green New Deal for Nature, I argued that giving land back to nature could be another part of this vision. Restoring forests and other natural habitats to 25% of the UK’s land surface could sequester 14% of the UK’s annual greenhouse gas emissions each year. As emissions are scaled down and these ecosystems expand, they could continue to remove much greater quantities of carbon dioxide (CO₂) in future.

Often called “natural climate solutions”, restoring forests and wetlands draws carbon down from the atmosphere and stores it in the tissue of new vegetation and soil. On a large scale, and alongside leaving fossil fuels in the ground, this could help to limit global heating to well below 2°C.

The Domesday Book of 1086 indicated forest cover of 15%, ‘but significant loss of woodland started over 4,000 years ago in prehistory’. By the beginning of the 20th century, this had dropped to 5%.
Defra

These habitats can be restored through rewilding, which means giving natural processes a helping hand by stopping the draining of peatland for example, or letting a woodland regrow. Reintroducing species that were once extinct in a region can also help ecosystems regenerate. While letting nature take care of itself isn’t appropriate in all cases, rewilding is one of the most powerful and cost-effective ways to resist climate breakdown and wildlife loss at the same time.

But what might that look like in practice?

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Read more:
You can rewild your garden into a miniature rainforest – Imagine newsletter #4

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The “green” in the Green New Deal

For wildlife, it’s important that restored habitats are connected. Linked habitats allow plants and animals to move more easily as temperatures rise and rainfall patterns change. If species can migrate through green corridors to cooler areas, they could avoid local extinctions. This could mean a network of expanded hedgerows and woodland that criss-crosses the land, connecting wild habitats and ensuring species can migrate safely between them.

Other changes include reintroducing European beavers to flood plains to help manage flood risks. In remote places like the Scottish Highlands, wolves could return to keep herbivores in check and help woodlands rebound, increasing their long-term potential to store carbon. Rewilding instead of burning or draining carbon-rich peatlands would allow their vegetation and carbon stocks to recover. Wildlife, from insects to birds and large mammals, would have space to flourish. The UK would switch from being one of the world’s most nature-depleted countries to a green and vibrant land.

Beavers have returned to the UK’s rivers after an absence of 500 years.
Abi Warner/Shutterstock

This may sound utopian, but it’s not. The UK is a densely populated country, and with 72% of the land area used for agriculture, it might seem that there’s little room for anything else. But less than 20% of the UK is occupied by crops or dense urban communities, so 80% of it could be better managed for nature and storing carbon.

Some 45% of the UK’s land surface is given to grazing livestock. The poorest land for agricultural productivity is only farmed because of taxpayer subsidies. Meanwhile, about 13% of the UK is allocated to grouse-shooting and deer-stalking, often on degraded peatlands that are managed at huge environmental cost for the benefit of a tiny number of hunters. This land is currently of little value for food production, but it could store plenty of carbon if rewilded.

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Read more:
Rewilding is essential to the UK’s commitment to zero carbon emissions

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The exact locations should be the subject of local knowledge and consultation, but reducing grazing land from 45% of the UK to 33% and returning that 12% to wild habitat could provide half of the carbon storage needed. Restoring half of the UK’s peatlands could add 6% more land, alongside protecting the 7% of the UK that is already broadleaf woodlands and wildflower meadows. Together, this would make 25% of the UK’s land a refuge for wildlife and a vast reservoir of CO₂.

The Lady Fen wetland in Norfolk was recently restored to 300 acres.
Tony Mills/Shutterstock

How can it be done?

Farm subsidies currently give £3 billion to UK farmers ever year. By some estimates, subsidies are half the income of many farmers. After Brexit, this money could be given to farmers to reward them for storing carbon and rewilding, making this more financially viable than grazing on agriculturally poor land.

Economy-wide carbon taxes could also pay for rewilding schemes, while the government could also issue green bonds to raise funds to lend to landowners, helping cover the early costs of restoring land to wild habitat.

Reducing the demand for farm produce from land will also be key to making space for nature. This means cutting down on the most inefficient use of land – farming for meat and dairy, which uses between four and 100 times the land area to produce a single gram of protein compared to beans, nuts and other plant sources. Policies which make it easier for everyone to eat food that’s healthy and sustainable – including less meat and dairy – are the final pieces of the puzzle.

Less climate change, more wildlife, and a longer life lived closer to nature. That’s a lot to gain from modest investments in how land is used in the UK.

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Simon Lewis, Professor of Global Change Science at University of Leeds and, UCL

This article is republished from The Conversation under a Creative Commons license. Read the original article.

We can ‘rewild’ swathes of Australia by focusing on what makes it unique

Eastern quolls have been introduced in Booderee Nation Park as part of a rewilding project.
Oisin Sweeney

Oisín Sweeney, University of Sydney; John Turnbull, UNSW; Menna Elizabeth Jones, University of Tasmania; Mike Letnic, UNSW, and Thomas Newsome, University of Sydney

Since colonisation, a dizzying array of Australia’s native species and ecosystems have been altered or removed altogether. It therefore seems natural to consider the idea of restoring what’s been lost – a process termed “rewilding”.

Now a global trend, rewilding projects aim to restore functional ecosystems. The rationale is that by reactivating the often complex relationships between species – such as apex predators and their prey, for example – these ecosystems once again become able to sustain themselves.

Rewilding has successfully captured the public interest, particularly overseas. Conservation group Rewilding Europe has a network of eight rewilding areas and a further 59 related projects, covering 6 million hectares in total.

The reintroduction of wolves to Yellowstone National Park in the United States remains the most recognised example of rewilding. The wolves reduced elk numbers and changed their behaviour, which allowed vegetation to grow and stabilise stream banks.

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Read more:
From feral camels to ‘cocaine hippos’, large animals are rewilding the world

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It’s not hard to see why rewilding is popular, given that it sounds a note of hope and inspiration amid the seemingly endless stories of despair over ecological disaster.

But in Australia, we need to do rewilding differently. The particular challenges we face with issues such as introduced species mean that, like Vegemite, our rewilding future must have a unique flavour.

Australian values

Our recently published paper builds on findings from a rewilding forum held in Sydney in late 2016. Academics, government and non-government agencies met to discuss some of the outstanding issues around rewilding in Australia. Despite the large, diverse audience and wide-ranging views, the forum succeeded in identifying some key themes.

Peninsulas often make good locations for rewilding in Australia because their geography allows the impacts of introduced predators to be minimised. Booderee National Park at Jervis Bay has reintroduced long-nosed potoroos, southern brown bandicoots and eastern quolls.

A much bigger Peninsula, Yorke, in South Australia, is the site of an ambitious project to reintroduce 20 species currently extinct in the area.

The widespread removal of dingoes has reduced natural control on introduced species such as foxes and cats. This in turn has allowed feral cats and red foxes to prey on small digging native mammals in the absence of a larger competitor. Meanwhile, declines in Tasmanian devils have been mirrored by declines in smaller predators like eastern quolls, and changes to cat behaviour, suggesting devils indirectly affect other species.

Many of these digging mammals have declined continent-wide and disappeared completely from other areas. This in turn has resulted in knock-on effects, such as altered fire regimes and changes to plant diversity.

It’s no surprise, then, that our workshop identified restoring predators and small mammals as priorities in Australia. Lots of work is already going on to restore small mammal populations, such as via Australian Wildlife Conservancy’s and Arid Recovery’s fenced exclosures, from which foxes and cats have been eliminated.

But exclosures are also contrary to the aims of rewilding, because they need ongoing maintenance and do not help the ecosystem inside to be self-sustaining. They can also exacerbate prey naïveté, whereby the native mammals fail to recognise and avoid introduced predators.

It may therefore be useful to view fences as a stepping stone to restoring small mammal populations to broader landscapes, helped by a variety of means including promoting co-evolution of native and introduced species, incentives to farmers, and the use of guardian animals.

Australia is different

Passive rewilding – the removal of human agriculture, resulting in the return of natural vegetation – has had positive impacts on biodiversity in Europe. It could have similarly positive impacts here, for example by increasing the density of tree hollows in previously logged forest and woodland. But a complete removal of management is unlikely to be effective because of, for example, the need to manage fire and the presence of introduced species like miner birds that exert influences on other species and even entire ecosystems.

In arid areas, simply removing agriculture is unlikely to halt the declines in biodiversity unless deliberate steps are taken to control pest plants and animals and to shift the ecosystem into a preferred state. In oceans, where rewilding is no less urgent due to declines in large predatory fish, passive rewilding may be more feasible, as marine protected areas can result in recovery of fish, provided certain key criteria are met.

Reintroducing large (bigger than 100kg) herbivores is part of rewilding efforts in Europe and Asia. Yet in Australia, all large herbivores are introduced and are generally perceived as having negative impacts.

“Natural” control of such species is not possible due to a lack of big native predators. Introducing “surrogates” of long-extinct predators (as are used elsewhere in rewilding) would have predictable results in terms of human acceptance (farmers wouldn’t like it), but uncertain impacts on ecosystems.

What about people?

People can benefit from rewilding – either directly, through wildlife tourism income or reduced kangaroo grazing on farmland, or indirectly such as via provision of services like flood control. So rewilding should not, as has been suggested elsewhere, necessarily separate humans from nature. Aboriginal owned and managed land offers huge opportunities in this regard because it covers 52% of the country and is home to many threatened species. In urban areas, rewilding will have to be a compromise between what is acceptable to humans and what benefits ecosystems most.

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Read more:
Should we move Tasmanian Devils back to the mainland?

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There is clearly an appetite among scientists and managers for bold interventions such as trial reintroductions of Tasmanian devils to mainland Australia to restore ancient food chains or allowing dingoes to return to areas where they occur at low densities and are functionally extinct. Rewilding’s focus on restoration of ecosystem processes can complement, but not replace, existing conservation approaches. For example, we still need to achieve a comprehensive, adequate and representative reserve network on land and at sea.

Development of a rewilding vision and strategy would be a valuable first step towards maximising the potential of rewilding, tracking success, and persuading governments to fund it.

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The authors would like to gratefully acknowledge the contribution of Dr Andy Sharp, Natural Resources Northern and Yorke Manager Planning and Programs, to this article.

Oisín Sweeney, Senior Ecologist at the National Parks Association of NSW, Research Fellow, University of Sydney; John Turnbull, PhD Candidate, UNSW; Menna Elizabeth Jones, Associate professor, University of Tasmania; Mike Letnic, Professor, Centre for Ecosystem Science, UNSW, and Thomas Newsome, Lecturer, University of Sydney

This article is republished from The Conversation under a Creative Commons license. Read the original article.

From feral camels to ‘cocaine hippos’, large animals are rewilding the world

Most of the world’s wild horses, such as the Australian brumby, are outside their historic native range.
Andrea Harvey

Erick Lundgren, University of Technology Sydney; Arian Wallach, University of Technology Sydney; Daniel Ramp, University of Technology Sydney, and William Ripple, Oregon State University

Throughout history, humans have taken plants and animals with them as they travelled the world. Those that survived the journey to establish populations in the diaspora have found new opportunities as they integrate into new ecosystems.

These immigrant populations have come to be regarded as “invaders” and “aliens” that threaten pristine nature. But for many species, migration may just be a way to survive the global extinction crisis.

In our recently published study, we found that one of the Earth’s most imperilled group of species is hanging on in part thanks to introduced populations.

Megafauna – plant-eating terrestrial mammals weighing more than 100kg – have established in new and unexpected places. These “feral” populations are rewilding the world with unique and fascinating ecological functions that had been lost for thousands of years.

Today’s world of giants is only a shadow of its former glory. Around 50,000 years ago, giant kangaroos, rhino-like diprotodons, and other unimaginable animals were lost from Australia.

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Read more: Giant marsupials once migrated across an Australian Ice Age landscape

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Later, around 12,000 years ago, the last of the mammoths, glyptodonts, several species of horses and camels, house-sized ground sloths and other great beasts vanished from North America.

In New Zealand, a mere 800 years ago, a riot of giant flightless birds still grazed and browsed the landscape.

The loss of Earth’s largest terrestrial animals at the end of the Pleistocene was most likely caused by humans.

Sadly, even those large beasts that survived that collapse are now being lost, with 60% of today’s megafauna threatened with extinction. This threat is leading to international calls for urgent intervention to save the last of Earth’s giants.

A wilder world than we think

Formal conservation distribution maps show that much of Earth is empty of megafauna. But this is only a part of the picture.

Many megafauna are now found outside their historic native ranges. In fact, thanks to introduced populations, regional megafauna species richness is substantially higher today than at any other time during the past 10,000 years.

Megafauna have expanded beyond their historic native range to rewild the world. Number of megafauna per region, in their ‘native’ range only (a) and in their full range (b)
Modified and reproduced from Lundgren et al. 2017

Worldwide introductions have increased the number of megafauna by 11% in Africa and Asia, by 33% in Europe, by 57% in North America, by 62% in South America, and by 100% in Australia.

Australia lost all of its native megafauna tens of thousands of years ago, but today has eight introduced megafauna species, including the world’s only wild population of dromedary camels.

Australia lost all of its native megafauna tens of thousands of years ago, but is now home to eight introduced species, including the world’s only population of wild dromedary camels. Remote camera trap footage from our research program shows wild brumbies, wild donkeys and wild camels sharing water sources with Australian dingoes, emus and bustards in the deserts of South Australia.

These immigrant megafauna have found critical sanctuary. Overall, 64% of introduced megafauna species are either threatened, extinct, or declining in their native ranges.

Some megafauna have survived thanks to domestication and subsequent “feralisation”, forming a bridge between the wild pre-agricultural landscapes of the early Holocene almost 10,000 years ago, to the wild post-industrial ecosystems of the Anthropocene today.

Wild cattle, for example, are descendants of the extinct aurochs. Meanwhile, the wild camels of Australia have brought back a species extinct in the wild for thousands of years. Likewise, the vast majority of the world’s wild horses and wild donkeys are feral.

There have been global calls to rewild the world, but rewilding has already been happening, often with little intention and in unexpected ways.

A small population of wild hippopotamuses has recently established in South America. The nicknamed “cocaine hippos” are the offspring of animals who escaped the abandoned hacienda of Colombian drug lord Pablo Escobar.

Colombia’s growing ‘cocaine hippo’ population is descended from animals kept at Pablo Escobar’s hacienda.

By insisting that only idealised pre-human ecosystems are worth conserving, we overlook the fact that these emerging new forms of wilderness are not only common but critical to the survival of many existing ecosystems.

Vital functions

Megafauna are Earth’s tree-breakers, wood-eaters, hole-diggers, trailblazers, wallowers, nutrient-movers, and seed-carriers. By consuming coarse, fibrous plant matter they drive nutrient cycles that enrich soils, restructure plant communities, and help other species to survive.

The wide wanderings of megafauna move nutrients uphill that would otherwise wash downstream and into the oceans. These animals can be thought of as “nutrient pumps” that help maintain soil fertility. Megafauna also sustain communities of scavengers and predators.

In North America, we have found that introduced wild donkeys, locally known as “burros”, dig wells more than a metre deep to reach groundwater. At least 31 species use these wells, and in certain conditions they become nurseries for germinating trees.

Introduced wild donkeys (burros) are engineering the Sonoran Desert, United States.

The removal of donkeys and other introduced megafauna to protect desert springs in North America and Australia seems to have led to an exuberant growth of wetland vegetation that constricted open water habitat, dried some springs, and ultimately resulted in the extinction of native fish. Ironically, land managers now simulate megafauna by manually removing vegetation.

It is likely that introduced megafauna are doing much more that remains unknown because we have yet to accept these organisms as having ecological value.

Living in a feral world

Like any other species, the presence of megafauna benefits some species while challenging others. Introduced megafauna can put huge pressure on plant communities, but this is also true of native megafauna.

Whether we consider the ecological roles of introduced species like burros and brumbies as desirable or not depends primarily on our own values. But one thing is certain: no species operates in isolation.

Although megafauna are very large, predators can have significant influence on them. In Australia, dingo packs act cooperatively to hunt wild donkeys, wild horses, wild water buffalo and wild boar. In North America, mountain lions have been shown to limit populations of wild horses in some areas of Nevada.

Visions of protected dingoes hunting introduced donkeys and Sambar deer in Australia, or protected wolves hunting introduced Oryx and horses in the American West, can give us a new perspective on conserving both native and introduced species.

Nature doesn’t stand still. Dispensing with visions of historic wilderness, and the associated brutal measures usually applied to enforce those ideals, and focusing on the wilderness that exists is both pragmatic and optimistic.

After all, in this age of mass extinction, are not all species worth conserving?

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This research will be presented at the 2017 International Compassionate Conservation Conference in Sydney.

Erick Lundgren, PhD Student, Centre for Compassionate Conservation, University of Technology Sydney; Arian Wallach, Chancellor’s Postdoctoral Research Fellow, Centre for Compassionate Conservation, University of Technology Sydney; Daniel Ramp, Associate Professor and Director, Centre for Compassionate Conservation, University of Technology Sydney, and William Ripple, Distinguished Professor and Director, Trophic Cascades Program, Oregon State University

This article was originally published on The Conversation. Read the original article.

Rewilding the Sea

The link below is to an article that takes a look at the possibility of rewilding the sea – something which is surely within our grasp.

For more visit:
https://www.theguardian.com/lifeandstyle/2017/feb/04/the-primal-thrill-of-sharks-the-emotional-case-for-rewilding-the-sea

Rewilding