100 Species, Number 5: Earthworm

David North, Head of People and Wildlife       

He thought of all the infinitesimal motions of the world, the obstinate, heartbreaking progress of an earthworm, eating its own route forward.

(Carrie Brown, Rose’s Garden)

The power of earthworms comes not from their individual strength but from their collective strength – something we in the conservation movement could perhaps learn from!

Earthworm, photo by Richard Burkmarr

Out of sight and out of mind. In your garden, in the fields and woods of Norfolk, and across Britain, from our Cley Marshes reserve on the Norfolk coast to the Cors Dyfi nature reserve on the Welsh coast (run by Montgomeryshire Wildlife Trust), uncountable numbers of worms are doing what worms do best, eating and tunnelling, and in the process building our Living Landscapes.

How often do we wonder about what lives under our feet – the life in the soil. Millions – no billions - of living creatures inhabit every garden, living their lives unnoticed in the soil. None are more important than earthworms. There are worlds within worlds under our feet – soil is a habitat that supports a myriad life forms, from the microscopic to the massive, including the earthworms most feared enemy, the mole. (A species for a later post perhaps!)

Worms are blind, deaf, have no spine, no bones, no teeth, a length of just a few inches and their bodies are 80% water. So why include them in my list of 100 species that make Norfolk? 

Well Charles Darwin said of the earthworm, ‘It may be doubted whether there are many other animals which have played so important a part in the history of the world, as have these lowly organised creatures.’ The power of earthworms of course comes not from their individual strength but from their collective impact – something it took the genius of Darwin to recognise. 

Charles Darwin, one of my naturalist heroes, was the first person to take earthworms seriously. Though perhaps seriously is the wrong term, as his research included getting his wife to spend many hours singing and playing music to worms to discover if they could hear! However from his observations of worms Darwin drew remarkable and profound conclusions. This interest in earthworms was encouraged by an observation made by his uncle Josiah Wedgewood (of Wedgewood pottery fame) who observed that pieces of brick he had spread in a field had slowly become buried. Darwin immediately thought from his studies that earthworms were a likely cause.

His great insight was to realise that the small changes made by the individual earthworms he observed , when multiplied by billions for all the worms in England, and across thousands of years, could bring ‘geological’ scale change.

As he modestly records, 'The subject may appear an insignificant one but we shall see it possesses some interest’. The results of his 35 years of observations on earthworms were published in his final book, ‘The Formation of Vegetable Mould, Through the Action of Worms, With Observations on Their Habits’ published in 1881. A book which surprisingly sold more copies in its first year of publication than ‘Origin of the Species’ achieved!

So how are earthworms landscape builders? Darwin estimated that an acre of grassland might support 50,000 worms and that the weight of their casts (posh term for earthworm poo) would amount to 18 tons a year. We now know that Darwin’s estimates were on the low side – indeed if you count worms of all species then an acre of good land could support perhaps a million worms!

To understand the importance of earthworm poo, sorry casts, it’s necessary to know a little about their lifestyle. Earthworms are a bit like archaeological JCB diggers. They tunnel through the soil, eating as they travel, passing the earth through their muscular guts and rising to the soil surface to leave their casts. In this way Darwin estimated they increase the depth of the soil by 0.2 of an inch each year. That might not sound much but try multiplying it up through time! In ten years an object on the soil surface will be buried 2 inches deep and after 1,000 years by 200 inches. So Darwin had cracked Josiah Wedgewood’s puzzle of his vanishing bricks. Earthworms are great survivors. Worms (though not our lumbricus terristris) have been around for at least 500 million years and survived at least five great extinction events. 

But worms of course provide far greater services to us than gently burying former cities and civilizations for today’s archaeologists to unearth. Earthworms have been described as ecosystem engineers. They change the structure of their environments. Their burrows allow both air and water to penetrate soils but also help prevent water-logging. It’s estimated the tunnelling or worms each year on an acre of grassland creates a drainage system equivalent to installing 2,000 feet of 6 inch pipe!

Darwin described earthworms as nature’s ploughs, 'The plough is one of the most ancient and most valuable of man’s inventions; but long before he existed the land was in fact regularly ploughed, and still continues to be thus ploughed by earth-worms.’ Darwin. 

Earthworms, including Lumbricus terrestris, by the way they feed, are very effective at increasing the organic matter in the soil. They pull leaves and decaying vegetation from the soil surface down into the soil. This method of feeding releases the nutrients locked up in dead plants, making it available to living plants. As they tunnel and feed they break dead organic matter into tiny crumbs with a large surface area that bacteria and fungi can then break down releasing plant nutrients.

Darwin’s observations on the importance of earthworms have more than been confirmed by scientists today. Indeed we are still discovering new benefits that earth worms provide. Recent studies have shown that worm casts contain strange structures of calcium carbonate but in the form of amorphous calcium carbonate which is a very strange and special structure. A single earthworm may produce between 0.2 and 4.3 milligrams of calcite a day. That doesn’t sound much but earth worm produced calcite could lock up 564kg of carbon per hectare per year. That’s as much carbon as would be locked up by tree growth if a hectare was planted up. Pretty amazing. Maybe it’s the earthworm that holds the answer to climate change. Its already busy working to protect us from sea level rise of course by raising the land surface.

It has even been suggested that the origins of human civilization and farming can be linked to earthworms. For the last 11,000 years of human history, ever since we first became farmers, people have benefited from earthworms tilling the soil and providing nutrients to our crops. It may be no coincidence that the first great civilizations, first cities, and perhaps even the invention of agriculture, occurred in areas rich in earth worms. The Nile, Indus and Eurphrates valleys, where our first great civilizations prospered, were exceptionally rich in earthworms. Earthworms in the Nile Valley have been shown to deposit up to a thousand tons of castings per acre per year, explaining the astonishing fertility of the valley. The rise and fall of civilizations may be as strongly linked to soil fertility as it is to emperors and kings, or human wars and battling philosophies. As Andre Voisin suggested, ‘One often reads of the thousands of slaves that built the Pyramids of the Pharaoh. In actual fact, these enormous edifices owe their existence in the main to the thousands of slaves inhabiting the sub-soil of Egypt.’ (Andre Voisin Better Grassland Sward 1960)

Darwin may not have used the term ecosystem service but he certainly discovered, and understood, the principle that people benefit from nature’s services. His pioneering studies on earthworms are still to my mind the best on an ecosystem service. He recognised the great truth about soil, which he refers to as vegetable mould, ‘‘All the vegetable mould over the whole country has passed many times through, and will again pass many times through, the intestinal canals of worms.’ (Darwin). 

Of course its not just people who benefit from earthworms. They are vital in the food chains of many other species. And it’s not just early birds that catch the worms, a whole host of wildlife, from shrews and voles to moles and badgers, rely on earthworms in their diets. This key role in food chains was understood by another great natural observer, Rachel Carson. She also recognised that worms ingesting soil would mop up and concentrate in their bodies chemical poisons such as DDT being used by farmers. She found that worms were able to take up huge quantities of persistent DDT from the soil without it killing them, but a small bird would be killed, or rendered infertile, by eating just 11 worms. Her studies led to the publication of Silent Spring in 1962, A book which did change the world and eventually led to the banning of these poisons. Even more recently it’s been shown that other poisons, such as PCBs, are broken down much faster in soils with healthy worm populations. Today worms are used both for pollution control and waste disposal.

So next time you stand in your Norfolk garden, or walk through a Norfolk wood or meadow, think about the worms under your feet. There is a whole world down there in the soil – a world as full of mysteries, dramas and magic; of predators and prey, food-chains and habitats, parasites and symbiants, as in our world. The hidden depths under our feet are as strange and biodiverse as any of the ecosystems in the superficial world of the surface. I wonder, when we own a nature reserve how deep does our ownership go? Do we own the world up to a metre down? 10 metres? 100 metres? Life penetrates deep – is that life part of our nature reserves? 

I don’t have an answer to that question, but I do know, if I had to choose one species that puts the life in our Living Landscapes, it would be the earthworm. They were once known as ‘angels of the soil’. That seems a pretty good name to me too.

 ‘I would not enter on my list of friends the man who needlessly sets foot upon a worm.’ (William Cowper)

Snowy images from Holme

After the recent snow at Holme thought I'd post some photos of the site in it's "winter wonderland" state.

                             Lavender Marsh looking towards Gore Point
 

                             Looking towards The Firs

   While photographing Lavender Marsh a hunting short-eared owl was a real bonus. 

Can you find the owl?



 

 



Five minutes of your time to help the Cley and Salthouse Living Coast project

You will hopefully be aware of the very exciting plans to expand Cley Marshes nature reserve through the purchase of 140 acres of coastal marshes to the west. This will join Cley Marshes to our reserve at Salthouse Marshes, create a much larger area for wildlife, allow us to improve water level management for wildlife over the whole area, and make what is already an outstanding, internationally important wildlife area even better.

Cley Marshes at sunset, photo by Richard Osbourne

 

Linked to this project we also want to improve both education and interpretation facilities for our visitors. This will be achieved through a new building, the Simon Aspinall Wildlife Education Centre, to be built behind the existing visitor centre. In this position the building will be almost invisible from the nature reserve and will provide a valuable new facility for the many groups, local residents and general visitors who come to Cley. The new centre will assist us greatly in engaging visitors with the importance of the wildlife and habitats of this coastline.

We have applied to the Heritage Lottery Fund (HLF) for support of the land purchase, its restoration and the new education centre which is where you can help. If you can spend five minutes completing our simple online questionnaire, the information you provide will be invaluable to support our application to HLF. This is a major project for NWT and Norfolk’s wildlife and the feedback we receive from our members and the wider public will help our bid for approximately £1.5million to support our vision.

Thanks for your help.

We would also love to hear why Cley is special to you. Did you first visit Cley as a child and see your first avocet or harrier there?  Have you brought your own children here to explore?  Share your special memories of Cley by emailing mycley@norfolkwildlifetrust.org.uk or write to us. We are on Twitter using #mycley. Demonstrating how important Cley Marshes is, and how it has inspired people, will help us secure the HLF bid enabling us to make sure Cley continues to inspire future generations.

January at Thorpe Marshes

 Chris Durdin, NWT Thorpe Marshes

NWT Thorpe Marshes in the spring, photo by Richard Osb

I'm lucky to have Thorpe St Andrew Marshes – often called Thorpe Marshes for short – a short walk from home. The Norfolk Wildlife Trust’s newest nature reserve, established in 2011, is a charming mix of grazing marshes, ditches, ungrazed fen and a gravel pit, now known as St Andrews Broad. There's year-round interest, though spring and summer are my favourite times, with flowers on the marshes and dragonflies over the ditches, including that local speciality, the Norfolk hawker. Cetti's and grasshopper warblers, a hunting barn owl and Chinese water deer can be heard or seen on my local patch on the edge of Norwich.

In winter, the Broad comes into its own, with good numbers of gadwalls, tufted ducks, pochards and teals, these ducks moving between Thorpe and Whitlingham Country Park, which is just across the tidal River Yare.

Snipe feeding, photo by Elizabeth Dack

I'd like to share news of a recent sighting. I often wonder how many snipe are hidden on Thorpe Marshes. On 9th January, having walked around the reserve, I'd managed to find nine. Then, at 10:45, there were suddenly flocks of birds over the marshes, so dense that at first they looked like starlings. In fact, they were snipe. I estimated 200, including one in the claws of a peregrine. The peregrine, clasping its prey, the snipe's long beak clearly visible, headed west along the river, presumably towards central Norwich and the cathedral, where peregrines nest and remain during winter. A second peregrine also showed, very briefly, perhaps the other one of the pair based at the cathedral. The falcons certainly explained the disturbance that had made the snipe take to the air.

I lead monthly wildlife walks at NWT Thorpe Marshes. If you'd like to join me, you can see details of these and keep up to date with recent sightings on the reserve on my website http://www.honeyguide.co.uk/thorpemarshes.htm

100 Species, Number 4: Rabbit, rabbit, rabbit!

David North, Head of People and Wildlife

Fluffy bunnies, maybe, but this is a species which has nibbled whole Norfolk landscapes into shape. The rabbits’ impact on so many aspects of our land, habitats and wildlife was only really demonstrated when 99% of them vanished following the introduction of myxamotosis in the early 1950s. Rabbits were also the foundation of an industry based on exploiting their meat and fur that lasted for centuries and had profound impacts on many parts of Norfolk, nowhere more so than in the Brecks. The rabbit was also a major pest, causing problems for both farmers and foresters. Love them, or hate them, their influence has been surprisingly large.

The rabbit, like the pheasant (see previous post) is another species which is not really native, though ironically today it’s usually seen as a force for conservation good rather than as an invasive alien.

The early origins of rabbits in England are somewhat contested. Most authorities have this species down as introduced by the Normans but others suggest that the Romans may have brought rabbits with them and yet others say they arrived with the returning Crusaders. However they first got here, they were highly valued, with managed warrens established and controlled by the Church.

In parts of Norfolk warrening was well established by the 1300s. The areas of land covered by warrens in the Brecks and West Norfolk was immense. The boundary banks of each warren could run for many miles and were often topped with gorse hedges in an attempt to prevent rabbits straying into neighbouring warrens. Great fortified warren lodges, often build to a standard design, housed the warreners. From the 1300s to the 1900s there were working warrens in the Brecks. At first, in early medieval times, rabbit meat was a luxury, the food of nobles and the Church. However in more recent times it became a poor person’s meat, and then from the 1900s was even used to produce pet food. The scale of the rabbit industry in Norfolk was huge. As recently as the 1920s one estate in the Brecks was still employing 30 warreners and killing 120,000 rabbits a year. Many Norfolk rabbit carcasses were exported to London for the meat market but there also developed a lucrative industry centred on Brandon based on their skins. Rabbit fur was used to produce felt for the hat industry.

Of course by the twentieth century rabbits weren’t just in warrens they were almost everywhere across Norfolk. I don’t know at their peak how many rabbits were in Norfolk but nationally between 1950 and 1953 more than 40 million rabbits a year were being killed from an estimated population of well over 100 million. Then came myxamatosis, illegally introduced from the continent by landowners. More than 99% of rabbits were dead within three years.

This sudden disappearance of rabbits revealed how potent an influence they had been having on landscapes and habitats. Rabbits don’t thrive in areas of long grass or woodland but their nibbling creates just the right conditions for them, producing areas of closely grazed turf and lots of bare soil from their diggings. Many rare plants and insects thrive in just these conditions. Remove the rabbits and long course grass soon grows up and eventually scrub or even woodland may develop on what was previously sandy grass-heath. Lose the rabbits and you lose a special habitat and a whole host of rare species that depend on it.

Today rabbits are once again widespread. Every rabbit kitten will suffer from myxamatosis during its first year of life but many now survive, rabbits having evolved a degree of resistance. On nature reserves such as NWT Weeting Heath conservation management includes looking after the rabbits by ensuring favourable conditions for them. Without rabbits the nationally rare stone curlew would not find the habitat favourable. It, like many rare Breckland plants, including the beautiful spiked speedwell and Breckland thyme, depends on short rabbit grazed turf to thrive.

So though the rabbit is without doubt an introduced species, today it finds a warm welcome on many Norfolk nature reserves. And then again, without the rabbit where would predators like the stoat, buzzard and fox be? So perhaps the rabbit, after many centuries here, should be offered citizenship rights. Love it or loathe it, it’s over here, and here to stay.

Thompson Common Koniks

Paul Waterhouse, Assistant Field Officer Breckland

 

The Konik is a very hardy and primitive breed of pony originating from Poland. They are a descendent of the ancient Tarpan horse also known as the Eurasian wild horse a now extinct species. Koniks have become a popular breed for conservation grazing in the UK, particularly on wetland sites. They are very well adapted for coping with wetland sites and the lush vegetation unlike many other breed. They are able to do this by putting on considerable condition (weight) in the summer and can then loose up to one-third of their body weight in the winter with no ill effect. However, in the future the adaptability and hardiness of this breed may prove that they are useful on a number of different habitats. NWT Thompson Common has a diverse range of habitats such as woodland, open water and wet grassland to name a few. In fact it is so diverse an amazing 34 NVC (National Vegetation Classification) wetland communities are found within the reserve, two of which are so unique they have not been classified. So by pairing the complexity of the reserve with the adaptability of the Koniks makes them the ideal species to graze the site.

Before starting with NWT I knew very little about horses and if completely honest was not all that fond of them. Having worked on a dairy farm for a short while I was familiar with cattle and was confident in moving and managing them. I became to know their temperaments and was able to predict their movements and reactions. Dairy cattle generally go in the direction you are pushing them with a bit of gentle persuasion. However, as I found out horses are slightly less predictable and quite often take you by surprise. 

Thompson Common is split in to a number of large compartments and we regularly move the ponies around the site taking into consideration a number of things including the condition of the site and also the condition of the ponies. As most people are aware our ponies are a little wilder than your average domestic ponies in fact we use the term ‘semi-wild’. So it is not a matter of putting a head collar on and leading them through a gate, we have to round them up. Unlike the cattle I mentioned above these ponies quite often turn back on you and change direction when you least expect it. Their behaviour when moving them can be very different from day to day, quite often relating to the weather conditions. Some days you just have to open the gate and let them trot through and other days they try to go any direction except the way you want. This is usually when it is windy and raining, the ponies primary senses, hearing, smell and vision used for detecting danger are distorted. This leads to them becoming nervous and skittish thus making it more difficult to predict their behaviour and move them.

As well as moving the ponies around the site we obviously keep a close eye on their health, weight and general condition. We do this several times a week, but once a month we carry out a more detailed ‘body condition score’ on each individual. This is a scoring system from one to nine, one being very thin and nine being extremely fat. This is a useful management tool which can provide an indication of necessary nutritional requirements and help prevent welfare problems. NWT aims to have their conservation herds scoring between 4 and 6. 

This is also a good opportunity to record other information such as the condition of the hooves and note anything else that may need monitoring or attention. To carry out these condition scores you need to be able to identify each pony individually, which is not an easy task in itself. When I first started with NWT we had 27 Koniks at Thompson Common (which to me all looked very similar) and it probably took me around six months before I could confidently put a name to a face, so to speak. Since then we have moved a number of Koniks off to other NWT sites leaving us with a more manageable herd of 13, who are hopefully going to be joined by some highland cattle in the coming months. Twice a year we are paid a visit from the vet and farrier who are both very experienced and knowledgeable. They carry out routine health checks and also trim any hooves that may not be breaking naturally. These ‘pony days’ as we call them can sometimes be very long, as we have to setup specially designed handling systems, round them up and also check each pony individually before usually moving on to another NWT site to repeat the process again. Though hard work, these days can be good fun and it often brings together a number of NWT field staff that may not usually work together. I now find working with these ponies very rewarding and can see what a fantastic contribution they make to the conservation of Thompson Common.

100 Species, Number 3: Pheasant

David North, Head of People and Wildlife

 

In the weeks leading up to Christmas large areas of Norfolk’s countryside sounded like a war zone. Fortunately civil war hasn’t been declared, nor were we being invaded, but the target of these fusillades is, in the main, one species of bird, the pheasant.

It is said that as much money is spent nationally by landowners on the ‘welfare’ of this one species as is spent by conservation charities and Government on the protection of all other wild bird species. 

When I first moved to Norfolk more than 25 years ago one of my most striking impressions, apart from its relative flatness - well I had moved from Wales - was the sheer numbers of pheasants that I saw. Pheasants lying dead on roads, pheasants standing in groups in the middle of country lanes looking lost (it was October), pheasants trying their best to commit suicide by diving from the verge into the path of my car, pheasants exploding noisily into the air causing me to jump on country walks, pheasants in my garden eating the bird seed... Norfolk had a lot of pheasants 25 years ago and it still does today.

Pheasant at East Carleton, by Duncan Macnab. Submitted to NWT online gallery

Not that I have anything against pheasants. The cock is surely one of our most striking British birds, if British we can call it. In sunshine they shine as bright and beautiful as kingfishers, though rather than blues their iridescent colour mix is of bronze, gold and black on their bodies plus blues, greens or purples, depending on the angle of the light, on their necks, topped off with those extraordinary, erectile red wattles around each eye. And that’s not all! They sport one of the longest tails of any British bird and strange tufts of feathers behind each ear which they erect when excited. And as a male in late winter will gather a harem of up to a dozen females that can be quite often! They are also more variable in plumage than almost any bird I know. A product of the long history of gamekeepers introducing different races: ring necked, black necked, melanistic ‘French blacks’, Michigan blue backs, fen pheasants, ‘Scandinavian’ are just some breeds that are favoured. In contrast the females are shades of brown, though with an attractive plainness and a quiet beauty all of their own.

So why have I included this species on my list of 100 species that made Norfolk? Well this is a bird that has determined the landscape of many large estates and much Norfolk farmland. It has even changed the routes of major roads and, I was about to say, caused whole villages to be destroyed and moved, but perhaps that was more to do with deer! Another story for a future post. However our history of obsession with this one bird is certainly an interesting one for any landscape or social historian, especially here in Norfolk.

So let’s start at the beginning, perhaps that should be with a ‘once upon a time’. To do this we need to go back at least 2,000 years, or perhaps even further, for, of course, the pheasant, with its brilliant tropical looking plumage, is not a British native species at all. This is an Asian bird. The first record of an introduction into Europe goes back to the story of Jason and the Argonauts who, in their search for the Golden Fleece, visited the valley of the River Phasis in the Colchis region of Georgia – hence the pheasant’s name, Phasianus colchicus, and returned to Greece bearing pheasants. Almost certainly it was the Romans who first brought pheasants to East Anglia. They left recipes, and pictured pheasants in their mosaics. It’s most likely that they kept pheasants as cage birds for the table. Doubtless some would have escaped. However there is little real evidence of wild pheasants in Norfolk until after the Norman conquest. What is more certain is that by the time of Henry VIII pheasants were established and were highly valued. Henry passed laws making taking a pheasant’s eggs punishable by a year’s imprisonment. 

Today in Norfolk we think of the pheasant as the game bird par excellence. I have no idea how many are released by gamekeepers each year into the Norfolk countryside but it must be a lot! Hundreds of thousands each year, perhaps over a million as it’s estimated that 35 million are released each autumn nationally. 

So what have been the impacts on the Norfolk countryside of more than 100 years obsession with this bird? On the plus side, the planting and management of many small farmland woodlands across Norfolk has been to provide cover for pheasants in the winter. The huge annual releases of pheasants into the countryside must also provide both carrion, through road kills, and live prey, for a whole range of predators, foxes, crows and buzzards among them. The provision of large amounts of grain in bins and hoppers scattered across farmland as pheasant food must also support large populations of rats that might not otherwise survive the winter. The now widespread practice of planting game cover and food plants in strips along field margins also benefits a range of other farmland bird species that feed on seeds. 

On the down side pheasants will predate a surprisingly wide range of native species, including reptiles such as slow worms, young grass snakes and adders, and of course countless caterpillars including those of butterflies and moths. It’s unlikely that the release of the sheer volume of birds of this size, some estimates are that between 10% and 20% of the biomass (weight) of all birds in Norfolk are pheasants, has no impacts on other wildlife. Around 40% of the hundreds of thousands of pheasants released in Norfolk come from France, either imported as eggs for the incubator, or as day old chicks. So, one wonders what risks, for example the inadvertent import of avian diseases, could arise with this trade.

Pheasants flying, by Elizabeth Dack.Submitted to NWT online gallery

However the biggest impacts of the pheasant in Norfolk have been on the big estates. Pheasant shooting, certainly from the late nineteenth century through to the 1950s, was largely a pastime of the wealthy. On these wealthy shooting estates the impacts of pheasant management ranged from the employment of game keepers, leading to the mass control of predators , sadly on occasions including the illegal persecution of rare birds of prey, to the landscaping of large areas of estate countryside specifically to favour game. Nationally a recent survey showed that gamekeepers manage around 7.3 million acres of land, an area almost the size of Scotland, and though not all of this land is managed for pheasants, in Norfolk the pheasant is by far the most economically important game bird.

The growth of the importance of pheasant shooting in Norfolk started on these big estates. A fashion gaining popularity in the late nineteenth century in part because of its enthusiastic adoption by the Sandringham Estate. This growing significance is shown by the game bags on major estates. For example, on Lord Walsingham’s Breckland estate, in 1821 39 pheasants were shot, rising to 1,011 in 1845, 2,887 by 1865 and 5,069 by 1875. Surprisingly early in this period game laws were established with the Game Act (1831) restricting the  pheasant shooting season to the period between October 1 and January 31, very similar to that of today. By the early 1900’s shooting was competing with fox hunting as the wealthy gentleman’s favourite pastime. The game books on the Holkham estate record over 104,000 pheasants shot over 30 winters beginning in 1900.

There is doubtless much more that could be said about the impact of this one species on Norfolk’s countryside. After more than 100 years the scale and popularity of the pheasant shoot remains as great as ever. However surprisingly little research seems to have been done on the impact of this beautiful bird and the people who shoot it, on social structures, landscape conservation and wildlife in Norfolk. That this bird, and the industry which now surrounds it, has had an impact, is surely not in doubt.