GOING WITH THE FLOW

The countryside in mid-Devon is perfect for my favourite way of exploring a new place. I was introduced to it by accident. Just after university, I spent a few months doing bird surveys for the old National Rivers Authority (NRA).

We were told that because we were working for the NRA we had a de facto right of access to walk the banks. That worked well for the most part, though I encountered the occasional grumpy farmer who took a different view. But when gardens backed onto the water, the legal position felt rather less secure. Still, permission was impossible to obtain from everyone in advance, and early in the morning wasn’t the time to start knocking on doors. If the gardens were big enough and the stream far enough away from the houses, I would sneak across, skipping through sleeping villages as quickly as I could.

In the heart of the Norfolk Broads there was a different problem. The rivers here are flanked by wet woodland known as ‘carr’, dominated by Alder trees but with a dense, virtually impen­etrable, tangle of reeds and scrub close to the water. There was one section along the beautiful River Bure that was especially challenging. Where it was impossible to push through bushes along the bank, I had to go into the woodland to try to find a way around. As I soon found out, this was fraught with danger. The Alders had their feet in soft, boggy and unpredictable peat. On one occasion I used a four-foot-long fallen branch to test the ground ahead and watched as it slipped down into the bog and out of sight. That was the final straw.

Other rivers were more mundane. In Northamptonshire there were long sections of stream winding relentlessly through dull, intensive farmland. These watercourses were sinuous ribbons of life across an arable desert. I was delighted to find Kingfishers nesting in the banks and watched on as they whirred past just a few metres away, tracking the path of the stream, just as I was.

I’ve never forgotten that spring. The joy of my first contract in nature conservation, the very idea of being paid to count birds, the nights spent sleeping (or trying to) in a Ford Cortina in order to get an early start each day. And, above everything else, the pleasure that comes from exploring an unfamiliar place by tracing the route of a stream running through it. Now, over thirty years later, I take every opportunity to revisit the experience.

Follow the course of an unfamiliar stream and you are guided by the landscape rather than a human construct such as a track or path. Mindfulness comes built-in because it takes a little thought and focus to pick out a good way forward. There are fallen trees to clamber over and waterlogged ground to avoid if you want to keep your feet dry. Of course, things don’t always work out well. There are days when the obstacles are insur­mountable - an unscalable fence or wall, an irate landowner or a private estate that cannot be circumvented. In a way, though, that’s part of the appeal. You are setting out on a small adventure and you don’t know at the start quite how it’s going to pan out.

Another benefit is that streams often flow through the best surviving places for wildlife. Valley bottoms are the most difficult parts of the landscape to farm intensively. In our part of Devon, strips of mature deciduous woodland survive where the risk of flooding is high and the benefits from felling too small to be worthwhile.

Here is another good thing about streams: they are always changing, so even if you revisit them, no two walks are the same. Much depends on the amount of rainfall over the previous few days. Heavy rain can turn a slow, gentle trickle into a raging torrent. In late autumn, once the maize fields have been harvested, some of the local streams run reddish brown after rain, seemingly made more of soil than water as they churn across the invisible rocks below. As the years pass, there are more gradual changes too. Bankside trees with roots weakened by water finally succumb. If they fall into the channel, they may block it. Deep pools develop behind them, and new mini waterfalls form where the water forces its way through. In a rare departure from the norm, natural processes are left to play out, untroubled by the controlling influence of humans.

I’ve become very familiar with one particular stream not far from home. I discovered it by chance when hunting the woods for mushrooms, quickly abandoning that task to track the stream instead. As it turned out, I traced it through the trees, across some old meadows and right back to its source in a patch of willow scrub, at the edge of the local common. For most of this length it averages perhaps two metres wide and only a few centimetres deep, though with occasional deeper pools.

This stream, like most in the area, does hold fish. It has Bullheads, though it took me a while to discover them because they are rarely seen swimming. Some people know them as Miller’s Thumbs, their enlarged head a reminder of the effects on the human hand of grinding grain into flour day after day. The way to find them is to walk the streambed and turn over large stones on the bottom. Here, under perhaps every twentieth stone, a little dark, fat-headed fish spends its day resting, trying not to be seen. This species is highly territorial and an individual might spend much of its life centred on that single stone.

There are other fish too. In the first week of April this year I was stunned to find my first ever Brook Lamprey, swimming serpent-like through the shallows. It looked just like a small eel but with a round sucker for a mouth. It plied its way steadily upstream, throwing its body into wide curves and shuffling across ridges where a mere trickle of water covered the gravel. These strange fish still look much the same as they did hundreds of millions of years ago, offering us a rare connection to the distant past. I was equally amazed to see a Brown Trout, about eight inches long and swimming in water so shallow that its dorsal fin broke the surface as it skittered across the gravel ahead of me. Presumably it had ventured here from lower, deeper reaches of the stream, looking for a place to spawn.

We hear so much on the subject of pollution that I often wonder about water quality in the local streams, although I have no real expertise with which to make a judgement. The soil run-off certainly looks alarming when at its worst.

I rarely see much evidence of invertebrate life in the water, though it must be present in order to support the fish. When I do see insects, they are usually species that live on the stream rather than in it. The pond skater shuns the fast-flowing sections, seeking out sheltered little bays where the water is calm. It is actually a type of true bug, closely related to the water-boatman or back-swimmer, and able to fly, allowing it to rapidly colonise suitable places.

Pond skaters behave much like a pack of miniature wolves, roaming the surface, looking for other insects that fall in and become trapped by the surface tension. They use their middle pair of legs to propel themselves across the water, steering with the back legs and keeping the front two spare for grabbing food. They exploit the very thing that traps their prey, picking up vibrations on the surface film, sensing a desperate struggle to break free and sliding over to put an end to it.

These insects are responsible for a delightful effect that I always look out for in sunny weather. Each leg gently depresses the film of water where it touches the surface. In turn, the tiny dimples in the surface tension block the light as it shines through the water, registering as a shadow on the streambed. A similar effect is made by whirligig beetles as they weave their frenetic, spiralling patterns on the surface. The shadows dance along the bottom in tune with the insect above, the whole scene flickering as Alder leaves wave back and forth across the sun.

Add the sound of the foliage swaying in the breeze and the gentle rippling of water over rock, and if there’s a more relaxing way to spend a few minutes in the local countryside, I have yet to find it.