When we try to pick out anything by itself, we find it hitched to everything else in the Universe.
—John Muir1
To the British eye, there was something strange about the rolling hills. In place of green grass or purple heather lay a soft carpet of oaks, broken by grassland. Within those hilltop woodlands were animals lost to us for a millennium – wolves, lynx and, from the Carpathians, a few returning brown bears.
It was the height of summer, and I was standing with naturalist Rob de Jong on a flowery hilltop in Hungary’s Aggtelek National Park. Here on the crown of a meadow, hill-topping swallowtail butterflies looked delightful as they battered one another senseless for the right to mate. The purr of turtle doves smoothed the air like a balm. I remarked to Rob what an amazing template this would be for the lifeless national parks of a country like Wales.
Rob’s response was simple. ‘Still dreaming, I see …’ Then he paused. ‘And why would you want such forests back? Yes, you get more lynx. But most birds do not like forests. Nor do most butterflies. Our wildlife loves people. Most of the birds in Hungary need people. Trees swallow the birds. Birds are adapted – to us.’ He paused. ‘For most birds, there is no such thing as the wild’.
Rob described hundreds of turtle doves thronging the wires in local villages each autumn, each raised at the edge of a hay meadow. We talked about the Alcon blue, a butterfly whose caterpillar is raised below ground, entirely by ants. Dropping from a gentian, the butterfly’s caterpillar ‘sings’ to passing ants, convincing them that it is, in fact, their queen. Sonically and chemically in love, they immediately pick it up, take it underground, and raise it as their own.2
Such sinister fairy tales, Rob said, do not play out in the ‘wild’. They happen, instead, in carefully hand-cut meadows, or those grazed by village cattle. The Alcon blue’s unique lifestyle, and the life of most Hungarian butterflies, Rob said, is down to human activity. Talking to Rob, there dawned on me a new and unsettling idea. Europe’s wildlife may have entirely forgotten the wild.
Rob explained how, in central Europe, the disturbance of human beings had become, over time, far more important to the survival of birds than the growth of forests. He pointed me to a fascinating book and told me to read it – so I did.
Species Conservation in Managed Habitats: the Myth of a Pristine Nature is written by German scientist Werner Kunz.3 It’s interesting reading for anyone who gets carried away with ideas of ‘wildness’, without attention to what that means for the wildlife caught up with our landscapes today. Kunz points out that across central Europe, from Germany to Slovakia and Hungary, populations of many of the birds vanishing in western Europe are in fact stable. He argues that human disturbance and scruffy open habitats, from fallow airfields to pear orchards and military bases, have all played a role in keeping these species alive. Kunz compares the ‘cleansing’ model of maximum-yield farming, in western Europe, to small-scale variety in the east. But he goes further. He argues that the return of ‘wild’ habitats could spell the end for many birds. Strangely, I immediately saw what Kunz meant.
For years, writing conservation pieces for Birdwatching magazine, as I tried to work through why birds were vanishing, the answers I had turned to were often far from wild. I’d looked to Polish villages to see wrynecks doing well, old hay meadows as paradise for shrikes, overgrown Herefordshire gardens as nirvana for spotted flycatchers, and gravel pits as safety for nightingales. Often, as I’d done my research, it had been the loss of human habitats, not a loss of ‘wilderness’, which had driven the decline of our birds. Wrynecks did not vanish from the wild but from earthy wooded farmland. Shrikes vanished not from pristine grasslands but grazing meadows beside our villages.
Kunz had found a way to encapsulate what I had been trying to express in my writing. In central Europe, human action still promotes a huge diversity of birds. Little of this diversity is dependent on ‘pristine’ habitats such as forest, but on broken landscapes. Kunz’s description of one such place where he made this realisation, an airfield, calls to mind some off-piste explorations of my own:
These ruined airfield areas were home to many birds and butterflies which had to make way for afforestation elsewhere ... On the dry areas of these airfields, I found skylarks breeding in large numbers; common snipe, redshank and crakes were nesting in the rushes of wetter areas and little ringed plovers had found suitable places to rear young on the destroyed runways.
In his travels, Kunz detects that in eastern Europe a lack of nitrogen fertilisers means that fallow lands stay open, low in vegetation cover and rich in flowers. Such low earthy landscapes sow wheatears, corn buntings and black grouse. Kunz finally arrives at a conclusion that many conservationists would agree with today:
In central Europe, many species do not benefit from too many large forests ... This is because central Europe was deforested by mankind thousands of years ago, and as a result is inhabited by species that have adapted to open habitats ... The open-land species were not threatened for centuries, because they could colonise agricultural land with no problems ... However this situation has not existed for half a century.
Kunz goes on to explain that many species, once common across agricultural landscapes, have been forced into the retreats of ‘wastelands in cities, industrial areas, motorway embankments, gravel-carrying sites, brown coal open-cast mining and military areas’.
Kunz is right that many birds, many of our most endangered species in Europe, have, over time, committed to the human world. He is also correct that as this landscape has changed, birds have been forced to specialise, as the way humans have disturbed the landscape has changed. Indeed, Britain’s derelict refuges are often more diverse, more important for vanishing birds, than its carefully managed reserves. British nightingales once deafened coppiced woodlands each spring – now, the scrubby confines of a fenced gravel pit form a better refuge. Whinchats once scratched their calls across our southern farms. Now, the military-owned Salisbury Plain is the only large-scale insect-rich grassland they have left.
As Kunz rightly points out, whilst agricultural disturbance in Hungary sits in harmony with birds from tree sparrows to great bustards, agricultural ‘cleanliness’ in western Europe results in emptiness and extinction. Such comparisons are useful in getting to the core reasons for bird decline. They do not, however, move us to a future. Returning to the agricultural ‘disturbance’ models advocated by Kunz is not viable. We cannot start a national scheme of reinstating crumbling pear orchards. We cannot start living in the past. Where would such a journey end?
Countries like Belarus and Romania may be fascinating reminders of our past, but they do not provide a viable model for our future. House martins once thronged London’s streets, feeding on flies from the dung dropped by cart-horses on cobbles. This was also a time of cholera epidemics.
We must instead look to new ways to reinstate the ‘disturbance mosaic’ in which our birds evolved to thrive. What is challenging is that many British birds are wedded to strange, unnatural places. Before jumping to rewilding, we need to consider the fact that, on first inspection, many of our birds appear to have forgotten the wild.
Deep in the coal heart of Manchester, Yorkshire and Durham, ‘wastelands’ of rotting elder, willow and birch hold the last viable populations of willow tits in Britain. Living under constant threat of having a supermarket or housing estate built over their habitat, willow tits find their favoured floodplain woodlands growing on abandoned coalfields, not in pristine river valleys.
If you’re wandering the bubbling banks of the River Tywi, in Carmarthen-shire, you may spot the sprightly shape of a little ringed plover. Black, white, with a gold-ringed eye, these birds blend remarkably well with the gravel spits in the river’s meandering flow. But most little ringed plovers in Britain blend even better with active quarries and landfill sites, when they arrive to breed each summer. These places recreate their native gravel river banks – on an enormous scale. Swifts, which once nested in ancient trees, have committed to our buildings. Almost every British corncrake is confined to a crofted field. Spotted flycatchers do better in rural gardens than in the countryside around.4 Blackbirds, once foraging in lawns created by wild grazers, now find worms on grass cut by lawn-mowers.
A whole range of birds have committed to thousands of years of living beside us. This not only makes them fragile – but also means that romantic rewilding of the ‘resurgent forest’ school of thought is not a clever starting point in their conservation. Battles to save the willow tit must first be fought on old coalfields. Barn owls must be saved along the very ditches that drained the fens. Birds like swallows and house martins have ‘stepped out’ of wild habitats so completely that they will most probably never return to them again.
There’s no doubt that today, in our degraded landscape, many birds are increasingly tied to a life beside us. Most often, however, they are simply making do. And many will continue to do so – until something better comes along.
My grandfather Fred once told me the story of a short-sighted girl who’d had a lot of stick at school for wearing big square glasses. Getting a boyfriend at last, she decided to woo him by proving that she didn’t need glasses at all. She carefully placed a pin at one end of a field, noting where she put it. That evening, she and her boyfriend were sitting watching the sunset from a hay-bale, at the opposite end of the field.
‘Look,’ said the girl, glasses hidden in her pocket, ‘isn’t that a pin glinting in the sun over there?’
‘Goodness, what amazing eyesight you have,’ said the boy, most impressed.
Carefully, the girl followed her remembered path and found her pin. Alas, her romance was not to be. As she walked back across the field, she tripped over a cow.
Conservationists like Kunz and many others have, like the heroine in our story, overlooked the enormously important role of cattle, and other herbivores, as the original agents of disturbance for European wildlife. Instead, the strange thought-leadership in ecology until recent decades has been that, until we came along and cut down the ‘primeval’ forests, the birds of open land were sitting around, being rare, and waiting for the trees to fall – that most of the birds in our ecosystem were not there. In future decades, ecologists will hopefully look back on such a position with bafflement.
The idea that early humans increased biodiversity in Europe by cutting down trees is, if given any thought, human-centric nonsense. As we explored in our first chapter, most of our birds show highly evolved feeding and nesting strategies, developed over hundreds of thousands of years, which would have evolved in the varied landscapes shaped by giant herbivores and then their smaller cousins. A turtle dove grubbing in the bare earth left by a disruptive herd of aurochs or boars, however, notices little difference if that agent of disruption, over time, becomes a farmer tilling a field edge. Arguments for time-freezing agriculture to save birds become irrelevant, and boring, as soon as you remember how the skylark, corn bunting and cuckoo evolved in the first place.
In recent years, the emphasis has finally moved away from mythical canopy forests and back to the basic rules that govern ecosystems. In seeking to restore wild landscapes, then, it’s wise to avoid some examples promoted as ‘primeval’.
In Poland, Białowieża, often called a ‘primeval forest’ because of its great age, had such a depleted population of bison for centuries that the last one vanished from the wild in 1921.5 Aurochs had died out here in natural herd sizes centuries before. A dark, closed canopy developed for centuries – its stewards, gone. Dense forests in Romania, appearing pristine and untouched, with their high densities of wolves and bears, are not entirely natural either. Bison, cattle and horses would all have shaped and thinned out these forests – but their herds are long forgotten. Large herbivores vanished so early in our history, before bears, before books, that we have all forgotten the critical role they played in shaping our landscape and birds.
Fortunately, other continents have escaped such ecosystem losses. Looking at the wooded African savannah, the key player shaping the landscape is not a lion. It’s a lot bigger and so is its effect. Elephants pull down trees and break up thorny bushes, and their droppings fertilise the land, sowing industrious communities of beetles. Their grazing actions create enormous grasslands, filled with Africa’s equivalent species of larks, pipits, shrikes and bustards. But if elephants vanish from the Serengeti, will future ecologists call its forests primeval, and natural, in a couple of centuries’ time?
India’s larger national parks, such as Tadoba, Kanha and Kaziranga, contain some of the richest, most varied wooded grasslands on earth. All the big players are still in the game. Each is contributing to structural diversity – indirectly, by planting trees (predators keeping small herbivores on the move), or more directly, by opening habitat (grazing, browsing, digging), planting new trees (defecating seeds) and breaking others to create scrub mosaics (coppicing). In India, you can still observe the role of native cattle – gaur, or Indian bison, our largest living bovine. These occur in herds in size from 11 to 50 individuals. Herds range up to five kilometres a day, and average just 0.6 animals per kilometre at any one time.6 This is what truly natural woodland grazing looks like.
Alongside grazing gaur, the Indian woodland landscape is also ‘opened’ by large herds of deer and wild boar, far outnumbering their predators. Predators, however, create the fear dynamics by which herbivores move around, and so new woodlands have plenty of areas to grow unmolested.
The ‘apex’ nature of the role played by large herbivores in pristine ecosystems is also very important. Wild boar have few predators, although large carnivores will take their piglets. Looking at wild horses in Mongolia, their foals are killed by wolves, but 70% of wolf attacks take place during only the first week of a wild horse’s life. Stallions can also kill wolves with a kick to the head: adult horses are no easy prey. Remaining wild cattle, like gaur, are every bit as feisty as Julius Caesar described Europe’s aurochs to be in his Gallic Wars.7 Even adult tigers will rarely tackle them if given any choice of prey.
This renders cattle, horses and boar dominant architects. These grazers and diggers, not tied to dens like predators, sit at the top of the ‘landscape design’ ladder. In India’s woodlands and Africa’s savannahs, the frenzied competition between trees and the animals that munch them creates the very diversity of habitats on which most birds depend. These disturbed animal–tree contests, catering for grassland, scrubland and woodland species in an extremely diverse mosaic, are revealed in some of the illustrations in this book. Take a good long look at Figures 5 to 9, showing Letea Forest, Kanha, the Serengeti, the Chernobyl wilderness and the Biebrza Marshes, before reading on. These images show how our landscapes should look – and they may be quite different to what you’d think. Where native grazing animals such as cattle and horses are present, a mosaic of grassland and trees is the landscape default. As a result, the many species of grassland, scrub and scattered trees thrive wonderfully well in ecosystems where large herbivores have either been preserved or restored. The images reveal some of the wonderful variety of our own lost, native landscapes.
In Britain today, by contrast, we worry about wetland birds like avocets on man-made islands, because gravel islands in wild meandering rivers are a habitat most of us have never seen. We worry about the number of sheep needed to create the right habitat for ring ouzels, because we’ve long forgotten that a hillside should be stewarded by horses or its juniper shrublands nibbled by elk. Wild processes, whether rivers flooding valleys as they should, beavers damaging trees as they should, or woodlands vying with herbivores to create wood-pastures – have long been lost. In Britain, our original large-scale habitats have changed so often, and so much, that we’ve forgotten what we’re supposed to be bringing back. Whilst African ornithologists know that elephants are the baseline architects that shape the Serengeti, most British conservationists have forgotten our wild cattle, our wild horse harems and the importance of beavers and boars.
But could we really do away with planting weed strips to save the turtle dove? Could we really have all our birds sharing the same landscape, not each one managed in isolated pockets? Can woodland and grassland birds sing side by side without a hundred management plans? It all sounds wonderful in theory. But how does it work in practice? Are Britain’s birds ready for a return to the wild?
Species may be surviving at the very limits of their range, clinging on in conditions that don’t really suit them. Open up the box, allow natural processes to develop, give species a wider scope to express themselves, and you get a very different picture
—Frans Vera8
Rewilding scares British farmers and conservationists, perhaps in part because a vision of our open lands and people’s way of life being swallowed by forests has become the interpretation of what rewilding means. In the Netherlands, however, rewilding has been a quietly effective conservation tool for decades – in a country smaller, and more crowded, than our own (Figure 10).
In the 1960s, a large area of coastal land along the Oostvaardersdijk was reclaimed from the sea. Originally intended for development, it fell into disuse and its potential for nature became apparent. By 1986, large areas of the Oostvaardersplassen, under the Dutch Nature Conservation Act, were set aside for wildlife: a coastal strip ten by six kilometres in extent. It was in this newest of lands, literally, that the Dutch conservationists of Staatsbosbeheer, the organisation responsible for managing the country’s nature reserves, decided to try something – something very old. They decided on minimal intervention, and to restore the best available proxy for a grazing mosaic last seen in the early Holocene.9
The Oostvaardersplassen was the first project to demonstrate how the coastal wetlands of southern England might once have functioned, and could function again in the future. The leader in this project has been Frans Vera, the Dutch ecologist whose work Grazing Ecology and Forest History was the seminal text in challenging the closed-canopy forest notion in the first place.10
Confronted with the extinction of tarpan and aurochs, the Oostvaardersplassen team populated the coastal plain with closely related proxy animals: herds of Heck cattle and konik horses. Red deer, now numbering in their thousands, were also left to roam freely and shape the landscape as they saw fit. Starvation became the main agent limiting expansion. As predicted, over time, a carrying capacity was reached, as in the Serengeti. Unlike in the Serengeti, however, no predators acted to ‘plant’ the landscape with trees by culling or moving the grazers. Likewise, there are no boar in the Oostvaardersplassen, so rotavation of the soil is missing. Another problem, which has reared its head in recent times, is that starving animals would, in the wild, be swiftly taken down by wolves. In the Oostvaardersplassen, however, they often linger and have been noted on occasions to suffer. So, in recent years, a humane cull has been brought into effect.
In spite of these obvious and clear limitations in recalling wildness, the Oostvaardersplassen has seen a remarkable resurgence in its birds. First and foremost, the prediction that over time this coastal marsh would ‘inevitably revert to dense woodland’ has been deftly disproven. What has formed instead is a state of equilibrium, with the animals determining whether succession happens or not. Indeed, long before the grazing animals were released into the Oostvaardersplassen, another keystone grazing animal had arrived by itself. We never appreciate it enough in Britain. It’s big – and it’s mouthy.
Huge flocks of greylag geese, arriving to moult in late summer, soon got to work ‘weeding’ the marshes. The worry that the marshes would give way, through succession, to reedbeds and then woodlands, was disproven not by the largest herbivores – but by some of the smallest. The greylag herds grubbed out huge quantities of marsh plants, preventing succession and saving conservationists a huge amount of time and money. The expectation at the time was that vegetation would swallow animals – not that geese, of all animals, would be responsible for determining whether that happened or not.11
In the Oostvaardersplassen, winged herbivores, in goose form, and four-legged herbivores, in horse, cattle and deer form, now function in tandem to create a predominantly open mosaic. Rather than people investing money in planting reedbeds or clearing woodlands, the grazers deliver a dynamic landscape free of charge. The Oostvaardersplassen remains richer for breeding birds than reserves elsewhere in the Netherlands – or almost any nature reserve of the East Anglian coastline.12 Reedbed birds, such as bearded tits and marsh harriers, the result of management schemes in Britain, have moved in and thrived, alongside penduline tits and bluethroats, which prefer mosaics of reeds and bushes. The blend of reedbeds and pastures has also allowed colonisation by great white egrets. The reedbeds, unplanted, grow in areas of low-lying water. These are increased by large ‘wallows’ left by animals. The herbivores, however, often unceremoniously trash areas of reedbed and create large areas of open pasture. This is unfortunate for marsh harriers, but excellent news for lapwings.
There are more tree-dwelling bird species in the Oostvaardersplassen than in most British woodlands. You have goshawks, hawfinches and lesser spotted woodpeckers in copses and willow tits in the scrublands – nesting metres from bitterns and lapwings13 Because the landscape is not managed, any one of these habitats, and its birds, is free to expand, or contract, over time.
In 2006, white-tailed eagles, which wisdom said would only nest in huge trees, moved in to nest in low willows: the first pair in living memory. They were not reintroduced. Feeding on herbivore carrion and fish, the eagles have since repopulated the Netherlands, with over 40 breeding pairs in the lowlands. Colonising spoonbills, feeding between the pastures and reeds, grew to hundreds of pairs. Few recolonisations of this magnitude, for example, have ever been seen on our Norfolk coastline.
As with any initiative that takes credit away from people, and dispels a whole set of previous beliefs at once, the Oostvaardersplassen has often been feared and criticised. Whilst complaints from animal rights activists about the starvation of animals were to be expected, the thing many conservationists have most struggled with is something terrifying indeed. It’s alien to nature reserves – and endemic to nature. Surprise.
If you run a reserve with targets, what happens if the targets go wrong? If you set a target and fail to meet it – you have failed. The world’s stock of wildlife, however, managed without targets until around the 1960s. So it seems possible that nature has a few tricks up her sleeve for managing without targets at all.
In 1996, however, shockwaves reverberated through Dutch birding circles. The 300 pairs of breeding spoonbills in the Oostvaardersplassen crashed, in just one year – to zero. Then, the Vera conservationists, content with exploring ‘non-linear’ conservation models, whereby natural processes are cyclical, did something pretty remarkable. They did nothing.
The team were not managing for spoonbills. They were not putting dynamic nature second to the paperwork of the European Union, designed to freeze wildlife in its current form. It seemed there had been an increase in foxes on the reserve owing to the carrion levels. Informed speculation was that the foxes, as they are prone to do, had robbed and caused abandonment of the spoonbill colony.14 Calls for changes in stocking regimes and man-made changes in the water table – aimed at reducing the carrion, to reduce the foxes, to increase the spoonbills – came to the fore. Happily, they were ignored. In the coming years, spoonbills recolonised. But now, instead of a concentrated colony in one place, they dispersed such that birds bred across a wider area than they had done before.
One of the key tenets of Vera’s rewilding philosophy is that nature does not run in straight lines. His observations are born out in any of the pristine temperate or subtropical ecosystems of the world. With a full assemblage of native herbivores in play, trees must grow through scrubland to avoid being eaten. Over time, they grow into denser groves of successful trees, which are grazed around, creating the range of birds that nest in trees and feed in open soils. But over time, even those tree glades will rot and fall. Grasslands take root, scrublands follow – and round, and round. Intact ecosystems containing large animals are not linear. They are cyclical.15
When researching the Oostvaardersplassen, however, even with an open mind, I was troubled by one paper in particular. It showed that since 1997, when animal stocking levels were increased in the reserve, the overall number of breeding pairs, in all birds, declined by one-third. As scrublands halved, bluethroats crashed from 280 pairs in 1997 to just 39 in 2012. Reedbeds also halved in size, with a predictable drop in reedbed birds. Dry grasslands have increased, as have dry-grassland birds. There had been just 246 red deer in 1997; by 2012 there were 1,898. There are now four times more horses than twenty years ago.16
Looking at the enormous herds of deer, horses and cattle in the Oostvaardersplassen, it’s important to remember that humans, the land gods still steering the reserve, decided on a certain amount in the first place. They also decided not to introduce competitive agents such as wolves. Even if the large herds in the Oostvaardersplassen roam free, they do so within 60 square kilometres. So the effect of grazing is more concentrated than on a natural plain. To me, looking at the enormous herds of horses and cattle in the Oostvaardersplassen, they did appear larger than the natural harem groups of wild horses in Mongolia, or wild cattle in India’s woodlands.
Worried by how ‘natural’ all this was, I put the question to Charles Burrell, chairman of Rewilding Britain and owner of Sussex’s Knepp Estate. His answer to my prescriptive question was a non-prescriptive answer: ‘Who is to say how many are too many? The animals determine the aspect of a landscape.’ For someone who had grown up with prescriptive conservation certainty, this was an interesting reply.
A lush coastal environment, for example, contains more abundant and nutritious forage than an acidic soil inland. Whilst Holocene Norfolk may have seen hundreds of horses and aurochs on its coastal marshes, nutrient-poor soils inland may only have been able to support lower densities, creating more densely wooded lands, rich in pine and birch. If you cross the plains of southern Africa or any largely intact ecosystem, such as the wilds of Alaska, concentrations of herbivores and omnivores like bears are no constant matter. The answer to ‘did nature look like the Oostvaardersplassen?’ may not, in fact, be empirical at all. Herbivory depends on the desirability of an area. In areas of grazing plenitude, you would expect larger herds – and more grasslands. Nature is shaped not only by the range of animals that are present but also by the choices exercised by those animals.
Two further factors, however, would make the Oostvaardersplassen more natural. One would be if the herds were free to roam along the entire European coast. The other, if predators harvested them too. But does the Oostvaardersplassen have to be perfect, for Britain to follow its example?
This Dutch rewilding experiment has revealed, for the first time in any of our lives, the rich dynamics of a temperate coastline – one where white-tailed eagles scavenge the fallen and habitats jostle and intermingle side by side. It kicks into touch the need for dozens of action plans for individual species, with each landscape type kept rigorously apart, like separate zoo exhibits, at enormous expense. Each year, new wild animals give the Oostvaardersplassen their approval. Beavers, like eagles, are rewilding themselves. A landscape has emerged that nobody guessed would exist – colonised by other species nobody thought would return. And as Frans Vera expresses it:
We’ve become trapped by our own observations. We forget, in a world completely transformed by man, that what we’re looking at is not necessarily the environment wildlife prefers, but the depleted remnant that wildlife is having to cope with. What it has, is not necessarily what it wants.17
While the Oostvaardersplassen is often attacked for not being truly natural, such an attack rather misses the point. It’s more natural, more robust, more diverse and more real than other models, including any of those currently in place in coastal Britain – and cost-effective to boot. And that, all in all, is not a bad start.
Competition between disturbance and vegetation succession is hugely productive for wildlife, resulting in the ‘margins’ where most of life lives.
—Charlie Burrell18
For the last ten years, Charlie Burrell and Isabella Tree have overseen the largest lowland rewilding project in Britain. It’s happening in southeast England, just miles from Gatwick, on Burrell’s estate in West Sussex (Figure 11). The premise is alarmingly simple. Give the land over to a suite of free-roaming large herbivores in very low densities; mimicking the herds of herbivores that would have roamed Britain in the past – and let them get on with it. This project’s scale and vision is unique in Britain, and it’s worth taking a moment to explain how it came about, especially as other farmers, too, could follow in its wake.
Charlie Burrell inherited a mixed arable and dairy farm, but on heavy Sussex clay terrible for growing cereals. The farm tried everything they could think of to make it productive, but after 17 years they were still making a loss. The story of how its owners slowly transformed the Knepp Estate is best told in Wilding, by Charlie’s wife, Isabella Tree.19
Inspired by the example of Oostvaardersplassen, and the grazing ecology theories of Dutch ecologist Frans Vera, the owners turned the estate over to a naturalistic grazing system and surrendered the management of the land to free-roaming herbivores. As part of a parkland restoration around the house and the northern part of the estate, the owners sowed and repeatedly cropped native grasses - to soak up phosphates and nitrates from the farming days. In some areas, they planted a Low Weald wildflower mix to increase native plant diversity. In the ‘Southern Block’, however, they allowed a vegetation pulse to happen before releasing free-roaming herbivores to do battle with the vegetation.
Flowering plants started to return. With the soil purged of toxins, the health of the estate’s open-grown oaks began to improve too. Below the soil’s surface, fungal networks, or mycorrhizae, symbiotic with the root systems of the oaks, made a gradual return. Eventually, orchids, an indicator of healthy mycorrhizae networks, began to appear in the middle of former arable fields.
Into the Knepp’s rewilding experiment were released fallow and red deer, Tamworth pigs, as surrogates for boar, Old English longhorn cattle, as surrogates for aurochs, and Exmoor ponies, as surrogates for tarpans. But the Burrells segregated their wildlife experiment. Into the northern block on the estate, they let loose only free-roaming cattle – into the southern and middle blocks, all the four-legged chaos they could muster. Knepp’s greatest resurgence in overall avian diversity has been in the diverse scrublands where the combined force of these animals is once again in play. This has, in many ways, turned out to be the most exciting area of all - a diverse mosaic of habitats – looking much like African scrub - where the tensions between vegetation succession and animal disturbance generate truly dynamic processes, and where biodiversity has rocketed.
If you try to ‘manage’ an ecosystem back to life, you will almost certainly fail. You might restore a target species here or there, but an entire network of plants and insects, all co-evolved, all finding one another – that is an impossible thing for human hands to recreate. Far better, Knepp has found, to hand over such a daunting task to Britain’s more experienced stewards.
Knepp’s insect repopulation has, in just 15 years, set an exciting blueprint for turning things around. Since the rewilding scheme began, 600 invertebrate species have been recorded. Dung from the roaming organic herds recruits armies of dung beetles of a number of species; the favoured food of little owls. Dung beetles like the violet dor, not seen in Sussex for half a century, have recolonised the land. These increases sit entirely at odds with the remorseless decline of beetles in the rest of Britain.
Over half of Britain’s butterfly species have colonised Knepp. The lost ‘clouds’, not seen in most counties since the pre-war days, are being seen a little more often. In 2015, in one section of the estate, 790 small skipper butterflies were counted. As you walk through Knepp in summer, you continually startle meadow browns, common blues and marbled whites from the grass. Knepp’s butterfly recovery has kicked into touch much accepted wisdom about the habitats of the spectacular purple emperor – a butterfly of ancient oak woodland, it was often said. Purple emperors now thrive here in the sallow groves; their caterpillars feeding on sallow leaves.
The invertebrate ecosystem at Knepp now grows richer by the season. Each year, it continues to reconstruct itself. An extraordinary 441 moth species have now been recorded at Knepp. The ragwort-feeding caterpillar of the cinnabar moth, a species declining in many areas, is on the rise. Ghost moths once again flutter in the night. Cuckoos, feeding on a range of large invertebrates, have increased in number, against national odds. Resurgent bats, of almost every British species, including the very rare Bechstein’s and barbastelle, also attest to Knepp’s aerial invertebrate abundance, as well as its diversity of open-grown trees, allowed to decay in peace.
For every family of invertebrates examined at Knepp, scientists are discovering the reverse of what is generally happening elsewhere across the British countryside. Knepp has been rewilded for just 15 years, yet little like this has ever been seen in our country before. Management, objectives, targets or nature charities have rarely, if ever, come close to achieving such wide-ranging success, in terms of abundance and biodiversity – even if, against all odds, they have preserved invaluable ‘arcs’ of particular species for future generations to enjoy.
The reason this is all so vital to saving our vanishing birds is that before this, there was there were few precedents for a mass resurgence in invertebrate abundance, and diversity, in British conservation. Yet all the Burrells appear to have done, as one critic put it, is ‘release a bunch of farmyard animals’. So what, ecologically, is happening at Knepp?
Commentators from all sides, Guardian and Telegraph alike, remark on the ‘Serengeti’ aspect of Knepp, especially in the southern block. It is the first thing that strikes you on arrival. Knepp’s rewilding relies on what it calls ‘self-willed’ ecological processes. Each animal architect exercises a different effect on the land.
Old English longhorn cattle, an old breed, have reprised many of the core functions of our lost nomadic cattle. In areas resistant to their browsing, scrublands have formed. Hawthorns, in response to being nibbled, have increased their production of tannins – and, at the same time, their density of spikes. These scrublands are now the home of nightingales and turtle doves.
When cattle are browsing an area, spiky bushes like hawthorn, blackthorn, dog-rose and bramble deter them. Plants and young trees grow underneath and within these bushes - using the thorns as protection. Fledgling oaks – the seeds of which are planted by field mice and that aerial forester, the jay - grow using the cover of these thorns as protection. The cattle carry up to 230 species of seeds in their gut, hooves and fur, acting as vectors for floral diversity.
At the same time, however, the cattle also create open glades and ‘control’ scrub. On the move across large areas of land, the herds never mow down an area to the ground, nor do they compact the soil, but instead they open up and maintain short grasslands. The extremely low density of cattle here is key to these results, with stocking units of 0.3 livestock units (or animals) per hectare, compared to 4-7 units on conventional pasture. Knepp’s stocking ratio mimics, as far as it is possible for anyone to guess, something close to our lost densities of wild, roaming herbivores.
The ecological role of free-roaming horses on the estate appears to dovetail in and around the grazing actions of the cattle. The Exmoor ponies take out the toughest grasses, and they also seize individual thistle-tops; ripping them off. Removal of these ‘rough’ areas creates the growing conditions for other plant species to thrive, which are favoured, in turn, by the cattle.
Knepp may one day have wild boar, but Britain’s Dangerous Wild Animals Act of 1976, prevented the reintroduction of these animals to the estate. So Tamworth pigs, a very old breed, fulfil a similar role. The pigs transform even ground into a rotavated rubble of chaos: a fresh start for plant and insect life.20 The exposure of bare soils by the pigs at Knepp, in the two weeks in May when sallow seed is viable, has allowed the sallows – upon which purple emperors depend - to colonise. Huge anthills have formed from pig-rootled turf. Solitary bees have colonised the open soils. But the most striking thing Knepp’s piggies may have achieved is a wilder vision for how best to conserve our vanishing turtle doves.
When Charlie Burrell took me around the estate, he was keen to emphasise the difference between the ‘southern block’ and the rest of his estate. It has horses in play alongside cattle – but it’s also the area where pigs, as well as red and fallow deer, are shaping the landscape. Of the eighteen singing male turtle doves present at Knepp as of 2018, where there were none before, some appear to be nesting in areas where pigs disturb the soil. Turtle doves are archetypal birds of open, weedy soils. They feed on the tiny weed seeds that grow here; a habitat promoted by arable farming only in the most recent of times.
At Knepp, against a backdrop of impending national extinction, turtle doves are thriving and increasing year on year. Not only do they have dense thorny scrub in which to hide their nests, but their diet is catered for by the abundance of wild weeds such as chickweed, grass vetchling, scarlet pimpernel, sharp and round-leaved fluellen, bird’s-foot trefoil and fescue, which produce the tiny seeds on which turtle doves thrive. Such successes have not been sown by arable farming, but the chaos of free-roaming animals instead.
Knepp is also shedding a new light on how deer, in more natural ecosystems, can play a far less destructive role when it comes to Britain’s birdlife. Whereas rampant deer browsing, by unnaturally high and confined numbers of deer in our woodlands, can destroy woodland diversity, the same is not being seen at Knepp at all. Indeed, deer, famous for removing nightingale habitat by browsing young trees out of woodlands, exist side by side with nightingales. In the southern block, the Burrells allowed a large vegetation pulse before the deer were put back in. By this stage, robust plants like hawthorn, blackthorn, dog rose and bramble, capable of repelling even cattle, were more than able to repel the nibbling of deer.
Now, red deer are springing another surprise on Knepp’s ecologists. We associate them mostly with our uplands, but at Knepp, given the choice, red deer show preferences for the wettest areas and swim in open water. Here, the richness of forage grows their antlers far larger than those seen on stags roaming the Scottish hills. Red deer debark trees (as bison, not currently present at Knepp, do as well, to great effect) – thereby contributing to the ‘pruning’ and opening of wetlands.22
Across the estate, as these intertwining four-legged stories run their course, the landscape grows ever more complex and diverse. Rather than being swallowed in ‘forest’, Knepp, the southern block in particular, remains a dynamic, shifting balance of habitats, as its grazers maintain open scrublands and meadows and prevent a shaded, species-poor forest from forming at all.
At Knepp, history is reversing in the way birds are using the land. Lesser whitethroats, it seems, did not come into existence with the hedgerow after all. At Knepp you can hear them blasting away from stands of cattle-prodded blackthorn.
Knepp’s thornlands are home to healthy populations of nightingales, which appear to fluctuate, naturally, in numbers – with seventeen singing males in 2018. BTO studies in 2012 suggested 79% of these were paired; considerably higher than the national average. Any idea that nightingales are woodland birds vanishes when you visit Knepp. These scrubland maestros are thriving here – not in shade, but in dense scrub whose growth is fuelled by sunlight.
Disrupting the careful labelling of habitats, birds as disparate on the conservation red list as woodlark, woodcock, yellowhammer and peregrine falcon (the latter nesting in trees) have all moved into Knepp. Nature is rampant – defying definitions of ‘woodland’ and ‘grassland’.
Knepp shows that Britain’s birds are ready for, best suited to – and most urgently need – a return to wilder stewardship. Most of all, the Burrell ethos of ‘let’s see what happens’ has, ironically, restored more insects, and more birds, than most areas driven by targets and outcomes.
The Knepp estate also shows how even the simple act of returning livestock densities to levels last seen in the nineteenth century, can recreate, in the ecological blink of an eye, a diversity and abundance of life not seen in many areas of Britain without our lifetimes. But it also recalls how our lowlands might have looked not just centuries but millennia before, in a time before farmland. At the same time, Knepp remains both radical yet profitable. It grows wilder every year, yet, in some respects, is still a tended landscape with livestock lovers at its root. Most of all, Knepp shows how rewilding need not drive people, or farmers, off the land. Far from it, Knepp shows, to farmers from the Welsh Hills to the dairy pastures of Somerset, how farming might plough its furrow long into the future. More profitable, more diverse, more humane, more robust - and better for both people and wildlife alike.