Monday, 31 January 2011

The changing of the guard

I begin my walk in darkness, part of a daily ritual at this time of the year. Stepping out into the gloom of the forest with the dogs, I am otherwise alone. I know this patch well and the dark, sometimes shifting, shapes and sounds of the forest no longer hold any fear for me. The sound of something large moving through the vegetation will be one of the many deer and the upright figure that haunts the edge of the track will be a now familiar piece of broken trunk. For many the darkness of night is an unsettling experience, no doubt a reflection of our reliance on the visual. Perhaps we hold within us some primitive fear, an echo perhaps, from our ancestors whose wild woods held the threat of large carnivores long since lost from our countryside.

I have always enjoyed the sensation of being out at night, away from the pervading light pollution that spoils so much of our landscape. The darkness reins in our sight but heightens other senses, most notably those of hearing and smell. The damp, soft air of the forest night holds onto the smells of passing fox and muntjac, and carries the harsh calls of territorial tawny owls and the high-pitched notes of nocturnal migrants like redwing. Whether it is the warm, moonlit summer nights out ringing nightjars or, as now, the pre-dawn walks on damp winter mornings, the dark of the forest embraces you, shortening horizons and engaging you more closely through senses that strain to grasp at sounds and smells.

There have been times, however, when some of night’s sounds have unsettled me. The crack of a rifle close-by or, once in a chestnut wood in Sussex, the sound of footsteps following my nocturnal perambulations. It turned out that the source of these footsteps was a pheasant that had been following me as I worked my way around a regular beat (at the time I was monitoring small mammals with live traps baited with grain). The pheasant had learnt that when I caught something I emptied the grain out and replaced it. My laughter upon discovering this was clearly an outlet for the tension of my nervous energy!

Night’s dark shroud can be slow to slip away on these winter mornings, particularly when the moon is spent or the cloud thick. As the deer retreat from the rides and clearfell, to seek shelter in the thickets and forest cover, so other creatures are stirring. Noisy wood pigeons, roused by my approach, explode from their treetop roosts in a crash of flapping wings, while the calls of crows hang in the air. The world is waking, and it is time to turn for home and breakfast.

Saturday, 8 January 2011

Winter birches brighten the landscape

On a dull winter afternoon, just before the weak rays of the sun disappear below the horizon, it is the Silver Birches that stand out against the darkness of the brooding conifer plantations. The silver-white bark of the birches seems to absorb some of the colour from their surroundings, the tint of the orange sky and the soft browns of the bracken. The birches take on soft bronze overtones and seem to glow, adding to the magic of the Breckland winter landscape.

There is something about these trees, perhaps echoes from a childhood spent on the Surrey heaths where the birches were seen by conservationists as unwanted invaders, scrubby raiders threatening the delicate heathland balance. But to me the birches were, and have remained, an important and welcome part of that landscape and I always associate them with sandy soils, heather and the chattering winter flocks of Lesser Redpolls. The Silver Birch is a pioneer species, an opportunistic tree that is quick to utilise vacant land free from competition. It was one of the first trees to follow the retreating glaciers in the march back north across Europe. The production of vast numbers of tiny, wind-dispersed seeds have played a part in the tree’s success, while nitrogen-fixing nodules on the roots have enabled the birch to improve the condition of the soil in which it found itself.

Foresters have also tended to regard the birch unfavourably, an unwelcome opportunist with a tendency to appear in the wrong place and to grow too rapidly. The birch is relatively short-lived for a tree, with few individuals reaching their own three score years and ten. Its timber is not widely used, although it once was in Scotland. It does have a number of craft uses, included in which are its use for smoking fish, being the wood of choice for this delicate process, and the use of its sap to make wine – something that is still a popular practice in some households.

For me, however, the birch has earned its place in my affections for a number of reasons. I delight in its airy habits, the way in which it appears in open landscapes on poor soils where other trees struggle to gain purchase. It is there at the margins, taking the first steps towards a colonisation from which others will inevitably follow. I also appreciate its wildlife value, supporting various fungi, many different insects and, of course, birds. Perhaps this appreciation is shaped by those childhood recollections and by the fact that I see parts of that Surrey landscape reflected in

Friday, 7 January 2011

There was a little fishy

At this time of the year the crayfish traps return very few crayfish, no doubt a reflection on the low temperatures and a period of semi-dormancy in these damaging crustaceans. The other day, for example, there were just two crayfish, one in each of the two traps. Also in one of the traps were three fish, a Three-spined Stickleback and two Bullheads.

Despite their unattractive appearance, dorsally flattened and with large head and mouth, I have a soft spot for these fish. This stems from childhood days spent catching them by hand in the local streams around where I grew up. As a child I knew them by the name of ‘Miller’s Thumb’, a local name which references the similarity of their appearance to that of the flattened, swollen thumb of a corn miller, caused by the countless testing of flour texture during the milling process. I had always assumed that this was a common and widespread fish but it turns out that this is no longer the case and it has been flagged as having an unfavourable conservation status across its European range, which extends from the edge of the Arctic Circle south to southern France.

What the Bullhead lacks in physical beauty it more than makes up for in terms of interesting behaviour. Not only can it survive in waters chilled to very low temperatures, hence reaching the Arctic Circle, it has most unusual breeding behaviour. The males are strongly territorial, defending a ‘nest’ that is typically a hollow placed under a stone or amid some woody debris, and look after the eggs and resulting young. The males produce acoustic ‘knocking’ sounds that are used to advertise ownership of their territory and, quite possibly, to attract a suitable mate. Research suggests that females can determine the size (and hence suitability) of a male by the nature of his sounds. Larger males are preferred because they are better able to defend the nest hollow against intruders and because they can cope better with the rigours of single parenthood, which can see males lose 20% of their body weight.

Favoured males may attract multiple females, each adding her load of sticky eggs to the egg mass stuck to the roof of the nest hollow. Females inhabiting lowland streams may spawn several times each year, while those in colder upland streams may just manage the one. Then it is over to the male to protect the eggs and see that they develop, defending them from other males and predators like trout and Signal Crayfish. It is great to see them in this section of the river but I do wonder how much damage the introduced crayfish have done to their population.

Thursday, 6 January 2011

Grey geese harbour a vagrant

With the exception of the chunky Greylag Goose, our wintering grey geese can prove something of an identification challenge, especially when seen at a distance or in the dull light of a winter’s afternoon. While the Pink-footed Geese, whose skeins sometimes number hundreds of individuals, are perhaps the best known of these winter visitors, there are others that provide the real draw for many of the county’s birdwatchers.

White-fronted Geese arrive from distant breeding grounds that stretch across the Russian and Siberian tundra, with most wintering in North Norfolk, around the Broads or down into Suffolk. The numbers wintering in our region are small when compared to those wintering in the south-west of England, notably at Slimbridge, and much reduced compared to the peak numbers seen here during the 1940s. At that time, up to 4,000 of these birds could be found feeding on the marshes at Halvergate or roosting on sands at Scroby. Today, numbers are a more modest 500-600. White-fronted Geese also breed in Greenland and it is birds from this breeding population that winter in Scotland and Ireland. Only occasional individuals from the Greenland population reach East Anglia, most often appearing in the company of the large flocks of pink-foots that feed on the fields inland from the North Norfolk coast.

The Yare valley is home to visiting Bean Geese, a species rather similar in appearance to the more familiar Pink-footed Goose. Here, the marshes at Cantley and Buckenham have become reliable sites at which to see these birds, with 100-150 present most winters. Cantley seems to be the more favoured of the two marshes, with birds only spending more time at Buckenham if disturbance levels at Cantley increase.

Over the last few weeks there has been a rare Lesser White-fronted Goose in with the other geese at Cantley. This species breeds in the narrow boreal zone, dominated by birch and willow scrub, which stretches across northern Fennoscandia and Russia. The westernmost parts of this population have declined dramatically, reducing the chances of individuals reaching our shores for the winter. The eastern component of the breeding population winters on the coastal plains of the Black and Caspian Seas, east to China, and so is far less likely to reach us. The situation has been confused, however, by recent attempts to reintroduce the species into former Fennoscandian haunts. The reintroduction programme, which involves the colour ringing of young birds raised by foster parent Barnacle Geese, has seen an increase in the numbers of Lesser White-fronted Geese wintering in the Netherlands and it is quite possible that one of the consequences of this work is the occurrence of reintroduced birds (or their young) turning up here in the winter.

Wednesday, 5 January 2011

A country in need of clean water

I was stunned to learn this week about the truly shocking state of our freshwater lakes, rivers and ponds, and to discover that clean water is now virtually extinct as a habitat in England. The figures speak for themselves; according to the Environment Agency there is not a single lowland river in England that has not been damaged, either chemically or physically. Some 87% of the headwater streams in south-eastern Britain are classified as biologically degraded and there is only one lake that is classified as chemically undamaged across the whole of England and Wales. This damage is having an impact on the wildlife of these waterbodies with, for example, CEH and Pond Conservation charting a 20% decline in plant richness in lowland ponds in just the last ten years.

It is not so much the stark figures themselves that deliver the sense of shock but rather the fact that we have tended to think of our rural ponds and rivers as being largely untouched by our activities. The twin evils of habitat loss and pollution have been insidious in their effects and the damage caused has not been apparent to the casual observer. The ponds and waterways are still there and they still contain life, just not as much as they did before. In the case of pollution, it has been the leaching of nutrients and biocides from agriculture, coupled with the toxic cocktail that runs off from our roads, that has delivered a decisive and deadly blow, an unseen venomous brew that has changed the delicate balance of species and numbers within our formerly diverse waterbodies.

It is easy to see why this has happened; we live on an overcrowded island, travel around in the selfish comfort of our cars and demand ever-cheaper food on an industrial scale. We have never been very good at looking after things that lie beyond our immediate horizons, the small things that are easily overlooked and dismissed as being unimportant. The scale of the damage already caused might seem bleak, and the solutions offered challenging, but there is hope in the efforts of conservation bodies to create new high-quality freshwater habitats and improve the condition of existing ones. Some of the ponds created in the last few years have already shown their worth, falling within the richest 1% of more than a thousand ponds surveyed for their biodiversity.  There is much still to be done, especially when it comes to restoring the condition of existing waterbodies and managing polluting run-off at a landscape scale. We need to build on the short term successes and tackle these landscape-scale challenges, safeguarding our aquifers and the clean waterbodies they should support.

Tuesday, 4 January 2011

Thrushes gather and turn to apples

It is only within the last few days that the birds have turned to the piles of apples, half-hidden by snow, that have sat in the garden practically untouched for weeks. The combination of snow, still several inches deep here in my parent’s garden on the Sussex border, and the berry larder now stripped bare, has driven the thrushes to seek out other opportunities, drawing in Fieldfares and Redwings from the frozen farmland fields and empty hedgerows. There must be a couple of dozen birds in and amongst the low bushes and the long dead architecture of summer’s growth. Blackbirds dominate numerically but it is the larger, more robust, Fieldfares that will have the ultimate say in the pecking order. The small, dark Redwings, with their prominent white eye-stripe and soft call are the birds that catch my eye though. I have fond memories of handling dozens of these Nordic visitors whilst ringing at a Norfolk orchard near Ashill and they are a very rare visitor to my Norfolk garden.

The Redwings are true nomads; pushing south in autumn from their northern breeding grounds they can be heard at night, their soft calls a much-stated omen of the approaching winter. The numbers wintering here are variable, reflecting the changing patterns of food availability and the vagaries of the weather. An individual wintering here in one year could just as easily be found wintering in northern Italy the following year. Because of their size and their preference for soil-dwelling invertebrates, Redwings can struggle when the winter weather is at its worst. Hard frosts and snow cover prevent access to favoured foods and, once the berry crop has also been depleted, they can struggle to find food. It is then that their mobility comes into play, the birds moving further south and west in search of food and more favourable conditions. Those that remain here will increase their use of orchards and gardens, with rural gardens more heavily used than suburban ones.

In with the Redwings there is a single Song Thrush, a species which has been seen less often over recent weeks if the reports that I have received are truly part of a wider pattern. Of similar size to the Redwings, the Song Thrush might also have been struggling with the unfavourable weather conditions. Again, individuals could have been forced south by the weather but some may have remained and succumbed to the bitter cold. We will have to wait for spring to find out.

The apples have become the focus of attention because there is little else left accessible. As birds jostle for this sweet resource, it is reassuring to know that this part of the apple crop has found a good home

Monday, 3 January 2011

Winter wonder

The ice changes everything; it shifts the focus away from familiar sites that I would normally search for wintering waterfowl. The lakes, so often packed with Coot and duck, are empty. Instead they carry a crisp skin of newly formed ice, highly polished thanks to the lack of wind and reflecting the bank side willows with photographic precision. The fishermen, quite sensibly, are nowhere to be seen and I have the reserve to myself.

Much of the activity is on the river which, ever in motion, remains ice-free. Small groups of Mallard drift away at my approach, while the more nervous Teal take flight, leaping into the air and away with a flurry of wings. Canada Geese and feral Greylags wander about the margins of the pits, unsure and seemingly bemused at the sudden change of state to their watery haunts. As they move across the shiny surface they slide each webbed foot forward, pushing down onto the ice. Am I imagining this or are they really indulging in something that resembles gentle skating? There is a sound to their somewhat unsteady movements, a harsh scratching noise, and I cannot work out if this is caused by their claws or comes from the ice itself, moving under the stresses of this additional weight.

In some places the ice is thinner and the occasional goose falls through; with much flapping of wings it tries to move forward, the ice sometimes breaking further but more often the goose shakes itself free of the cold, dark water. A larger area of open water holds a few dozen coot, a handful of Tufted Duck, a single Goosander and, amazingly, a drake Goldeneye. This stunning black and white duck is a rare visitor to the lakes, being more commonly encountered on the flooded margins of the East Anglian coast. This is probably only the second or third record for the site and a welcome one it is too. Although there is a small but expanding breeding population of this delightful duck in Scotland, this bird may have come from the larger Scandinavian population which breeds on freshwater lakes and pools surrounded by conifer forest. It is also remarkable that this particular bird is an adult male, since it is the females, which winter further south than the males, that dominate our wintering population.

Since the light is pretty good I get a decent chance to watch the Goldeneye through my telescope as it dives deep into lake in search of food, buoyantly erupting from the surface at the end of each dive. It won’t remain here for long, especially if the ice increases its grip on the lake, so I am fortunate indeed to stumble across it.