see also notes on bird hides and on rewilding where I wrote about the dilemma of the National Trust at Wicken Fen: what to do about large mammals suffering and dying, and how to control introduced populations of herbivores, konik ponies and highland cattle at Wicken Fen, which have no natural enemies, wolves being out of the question. Birds are rarely a problem; how often do you see a dead bird, although millions and millions of them die every year? Most of them are small and swiftly eaten by maggots, beetles, other birds.

The same issue soon came up in the Knepp estate rewilding project. Here too they were tempted to leave carcasses to decay, so many creatures would consume them they would make a rich addition to the bio-diversity of the place. According to the law wild animals may be left, but farmed and domesticted ones may not, and whatever status Knepp may assign to the animals on the estate, in the eyes of the law they are not wild. Hence, I suppose, it’s no one’s responsibility to take care of road kill. Roadsides are so filty that animals quickly lose all resemblance to living creatures, they become just dark, shapeless lumps or lumpy tattered filthy rugs which cause less offence at 60 miles an hour than all the plastic and cans on the roadsides which keep their colour better.

Anyway, at Knepp as at Wicken fen they quickly realised that quite apart from having a legal obligation they couldn’t expose their visitors to death. Strangely though on Attenborough some people think that killing makes the best bits. But the cheetah’s or the lion’s leap, the fall of the antelope with its throat in the grip of the predator’s jaws, those scenes are very different from a smelly carcase, and besides, the show moves on, sweet babies will soon be frolicking.

This body of a deer lay beside a farm track near here.

Anyone who’s been walking in the hills of Wales or northern England will have seen sheep carcasses, with sheep the thick wool usually hides the decay beneath, and will know that farmers don’t always obey the law.

Oostvardersplassen is a nature reserve in Holland, not far from Amsterdam, the child of Frans Vera, who was determined to go through with the logic of rewilding, even if that included allowing animals to die of hunger and cold. Dramatic fluctuations in populations of birds and animals are of course natural, but no one wants to go on a family outing to see animals starve to death. Angry locals were throwing food over the fence at Oostvarderplassen. Eventually Vera had to give way.

All creatures great and small have wandered in search of a better life or survival. As well as decline and extinction we hear stories of new arrivals to Britain from the hot, dry south. After the destruction of Adventurers Fen in 1940 Eric Ennion remained optimistic. But of course the refugees are nearly all winged. Here in Ely last year I saw the glossy ibis paddling and poking in the mud, conspicuously exotic, like a gawky black curlew, trying its luck out of north Africa. Mammals in nature reserves are not free to migrate, the locals are protected by fabulously expensive deer fences.

I was going to add to the notes in the above paragraph a link to another post which would explain the reference to Ennion’s optimism, but now I see that I haven’t actually written that post. There are only notes. Recently I have written several drafts which I’ve not finished. Anyway, it’s part of what should be a much longer piece about Adventurers Fen which I’ll just quickly outline here becuase it’s important to the business of migration and survival. Adventurers Fen lies next to Wicken Fen, the famous National Trust nature reserve, and has an extraordinary history. It is so called after the capitalists of the 17th century – some adventurers risk their lives, others their money – who financed its draining. That ‘improvement’ was not altogether successful, and by the late 19th century, when most of the fens had been brought into cultivation, Adventurers Fen, like Wicken Fen next door, was still fairly wild and swampy. Reed cutters still worked there, so did peat diggers, reeds for thatch and peat for fuel. The locals were powerful enough to have their way until the food crisis of the First World War when cheap imports were in short supply. So renewed draining and ploughing. Between the wars, when Ennion was a boy, agricultural activity gradually declined as imports grew and farmers grew lazy, unwilling to invest in the expense of continual maintenance of the drainage systems. So he was able to learn about nature, and birds in particular, through experiencing a form of steady, inadvertent rewilding, and came to understand natural processes, the dynamism of nature, the clever opportunism of birds, as the fen grew steadily wetter. This all came to an end at the beginning of the next war, the next food crisis. From the preface to his book: In a few short weeks the scoops (of the dragline) had torn a channel twenty feet wide from end to end, ripping the backbone out of Adventurers Fen. The water…. bled in an endless trickle into the deep, new drain. It hurried, brown and swirling under a scum of broken reed roots….When all was dry men set the fen on fire. spurts of fame began to flicker here and there and presently leapt up to redden the fringes of the great smoke cloud which hung above them…… reed beds, sedges and sallows vanished in a whirl of flying ashes amid the crackle and the roar. I went down afterwards. There was a single gull wheeling over the dead black land and a wild duck trying to hide in two inches of water at the bottom of a drain.

This must have been devastating for Ennion, but he is able to end the book with these words: (The kingfisher) would not worry overmuch to find its living gone, the pools dried up, the fen laid bare. There are little fish and broken rails to sit on in plenty of other places. It must be so. Nature cannot let sentiment usurp her laws: that is for us to feel. Adventurers Fen in all its loveliness is gone but nature goes on elsewhere.

Ennion too ‘went on elsewhere,’ following the birds. But note ‘plenty of other places’: there lies the difference between then and now, the difference between the anthropocene and all other times. In the same way, there used to be more possiblities for people. When people could move out of Asia, travelling westwards, when people could move out of Europe, travelling across the Atlantic, and keep on moving westwards like migrating birds, although less able to accommodate the locals than birds are. But like the birds, people keep on trying, although it becomes more and more difficult for them, as the fences get higher and the boundaries more strict. Possibilities, fresh pastures, new lakes do still exist. Birds are still ingenious. I drove to the Cambridge Business Park, clean steel and glass buildings arranged around a big old gravel pit which have filled with water, and there was a kingfisher, perched on a rail. Anyway, in these posts are a few references to Ennion etc., and I still mean to fill out the story, which is exraordinary. Three people watched that fire on the fen. One a full feathered fascinating fascist, James Wentworth Day. One, Alan Bloom, the newly arrived farmer who had started the fire, and Ennion himself. They all wrote about it, but all seem scarcely aware of the others. One day.

I began to read Isabella Tree’s Rewilding sceptically but found it inspiring. Their activities at Knepp – some of which are things left undone rather than done – have such a seeming spontaneous, rippling effect. There are plenty of spring-watch divas, nightingales and turtle doves but also, well, how about this: With the grazing animals no longer taking avermectins- the powerful wormers and parasiticides with which most domestic horses and all livestock on non-organic farms are habitually dosed – we were seeing cowpats and horse dung unlike anything we had seen outside Africa, latticed with the holes of dung beetles…. summoned by the smell and zeroing in like attack helicopters the beetles fold their wings and plop straight into the dung. If a crust has already formed, they bounce off and then have to scamper back into it, burying themselves headfirst in nourishing excrement.

Attenborough! I want to see that! The dung beetles then perform a role similar to that earth worms, tunneling, taking the dung deep into the soil to the nest chambers for their larvae, and because they eat parasites in the dung they reduce the need for avermectins. And little owls, just arrived at Knepp, like to the eat them. However I do feel sceptical about Tree’s last word on the beetles: apparently by ancouraging the growth of healthy grass they save the British cattle industry £367 million a year. They manufacture numbers for everything. Take the shocking pothole crisis. Billions! But surly if I get to work late because of an imperfect road surface, I’ll leave for work earlier? I’ll stay at work a bit later? And if my suspension is worn out sooner than it otherwise would be, isn’t that good for the economy? Good for manufacturing industry, good for car mechanics? And if cars are somtimes forced to creep along, isn’t that good for the mental health of pedestrians, saving the NHS X millions in anti-depressants and tranquillizers?

One more example from Knepp: free ranging pigs turn up the turf in search of roots and invertebrates. Wrens, dunnocks and wrynecks follow them. Solitary bees nest and ants start new colonies in the clods of earth. The ants attract mistle thrushes, wheatears and green woodpeckers. In one study, carried out in Romania, seven green woodpecker chicks consumed an estimated 1.5 million ants and pupae before leaving the nest. Amazing. Now that number I do believe. (Why? Faith in scientists? Confidence in the patience and numerical skills of devoted PhD students?) On sun-warmed ant hills lizards and small copper butterflies bask, and grasshoppers lay their eggs. The soil of the anthills has a different composition from the surrounding acid grassland which encourages the growth of wild thyme and different types of lichen, fungi and mosses. One last number: twenty three species of dung beetle in a single cowpat.

All this is stepping back and allowing nature to flourish. A moving glimpse into the complex wonders of creation to set alongside – well, here’s something I heard the other day. People treat their dogs with worm killers and flea killers and often brush and trim their coats and leave tufts of lovely silky hair lying in the garden which blue tits take to line their intricate nests. The presence of poison in the dog har is enough to kill the nestlings. This reminds me of the British in North America, giving blankets infected with smallpox to the locals, the difference being that there the genocide was deliberate.

On the other hand I also read that blue tits love bird feeders so much that they are out performing other small birds, whose numbers suffer as a result.

At Knepp several species near the top of the food chain were introduced: pigs, beavers, ponies, deer, cattle (all breeds close to wild species,) but not the real top dogs, wolves. Nor have eagles or vultures arrived. So questions of management, of stewardship and the reassertion of control become insistent. It’s not all about stepping back and wondering at the richness of nature. Castration or culling or contraception? Huge vet bills, as at Wicken Fen. Farming becomes a good idea again. The Trees (Charlie and Isabella at Knepp) became interested in a project on Dartmoor for the conservation of the feral ponies, where they decided that eating some of them, becoming the wolves, was the best option. But then there’s the British horse meat taboo, which turned out not to be as strong as the Daily Mail thinks it is. Must be all the immigrants. However, pony sausages and roasts are now available in pubs and farmers’ markets in Devon, though not yet in Sussex.

Yesterday evening the Merlin bird app kept telling me about a kingfisher but I couldn’t see it. I looked and looked and although I could clearly hear it, it remained invisible, until finally, a pair! Just a few feet above the water on the other side of the river, close in to the trunk of a big willow, among ivy and dead wood, restless, noisy. They really are almost common! And just on the edge of Ely, right next to the railway bridge, not bothered by the huge noise of the mighty diesels hauling their long lines of containers from China.