Saturday 12 December 2009

Berry good year


It has been a good year for many trees and shrubs, with an abundance of fruit and berries testament to a perfect season weather-wise. Many of the county’s hedgerows are replete with berries, delivering a blur of ripe red colour as you drive along the lanes. This natural larder, currently well-stocked, will support various thrushes through much of the winter; that is, unless it is hit by a hard and damaging frost.

Many plants produce berries as an incentive to birds which, having ingested the berry and the seeds contained within its pulpy coat, will act as dispersal agents, delivering the seeds ready-wrapped in fertilizer to a new site. Given that plants are not mobile, but rooted to a particular place, this form of seed dispersal enables them to colonize new areas. The relationship between the plants and the birds appears to be a mutualistic one, the plant getting help to disperse its seeds and the bird getting a meal in the form of the pulpy berry that surrounds the tough-coated seeds. However, it is complicated by the fact that some birds eat the pulp but discard the seed instead of ingesting it. Others eat the seed and discard the pulp.

Watch the berries in your garden and you might notice that some seem to disappear just as soon as they ripen, thanks to the efforts of thrushes or Starlings. Other fruits, however, remain throughout the winter and are the last ones to be taken by birds. These differences may be related to the composition of the berries, something which may change as the season progresses. For example, many berries show a decrease in their water content over time, matched by an increase in the quantity of lipids (a group of organic compounds that are made up of oils and fats, and which make up the structural components of living cells) they contain.

You might also notice that differently coloured berries may be taken at different times, with red berries taken before yellow, which in turn may be taken before white-berried forms. Recent research suggests that berry colour may reflect nutritional quality, with berries that are black or ultraviolet-reflecting containing higher levels of certain antioxidants.

While the preferences of birds for particular berries may be more complex than you might have imagined, there are implications if you are thinking about planting some berry-producing shrubs this winter. The key is to provide a number of different shrubs, which offer fruits of different sizes and which ripen at different times, thereby extending the fruiting season throughout as much of the winter as posisble. More advice on what to plant can be found at www.bto.org/gbw/plants.

Friday 11 December 2009

Lists have a value


Many female readers may subscribe to the view that certain men (and I don’t want to generalise here) have a thing about lists. For some men this fascination with listing and cataloguing takes the form of a collection, perhaps of stamps or coins; in others the item being ‘listed’ or ‘collected’ is more ephemeral and one can include train-spotting or twitching within this particular form of listing. Twitching, for those who do not know, is an extreme form of birdwatching where the object is to see as many different birds as possible, keeping a list for a particular area (say Britain) or for a particular period (a year list or a life list).

Needless to say, there is an element of competition that comes from such listing and twitchers will often brag about the size of their list (assuming it is bigger than that of those to whom they are bragging)! While this competitive element can generate light-hearted banter among birdwatching friends, it can sometimes lead to angry scenes as birdwatchers jostle to view a particularly rare bird. Such behaviour gives birdwatching a bad name and is the main reason that I avoid large twitches.

As a birdwatcher with a much wider interest in natural history, I have never really been into keeping lists, at least not in the form of ‘collecting’ birds as if they were stamps or coins. I keep field notes, listing what I have seen when out and about, noting down the numbers of individuals involved and any interesting behaviour that I have been fortunate enough to witness. Such records are then fed into county bird reports, periodic surveys (such as the BTO’s Bird Atlas project – www.birdatlas.net) or into the articles and books that I write. Over the last few years, however, I have been transferring many of these records into site lists for BirdTrack – an online project that uses lists to monitor the arrival and departure patterns of migrants and the change in status of species over time (see www.birdtrack.net for more information). To me, such projects greatly improve the value of my birdwatching, helping to underpin conservation efforts and support important scientific research.

I am always amazed by how few of the birdwatchers that I encounter at Norfolk’s nature reserves have notebooks into which they record sightings. I am equally disappointed when I do end up at a twitch by how little attention is given to the other birds that happen to be at the same site as something rare. Surely, these other birds are as important as something from the other side of the world that has turned up here by chance. Just think, if these ‘listers’ kept proper lists they’d get more from their birdwatching.

Thursday 10 December 2009

Catch up with our grebes


Strange as it may seem, winter is a good time to catch up with the five species of grebe that either breed or winter within the county. When people think of grebes, they often have an image of the Great Crested Grebe, resplendent in its breeding finery and indulged in an elaborate courtship dance, or the Little Grebe – the dabchick of smaller waterbodies. Both species are less showy in their winter plumage and both may leave their breeding waters to winter elsewhere, where they may swim alongside Red-necked, Black-necked and Slavonian Grebes, all winter visitors to Norfolk.

A trip to the coast can provide views of all five species in a single day and, sometimes, at a single site. The Little Grebe makes use of brackish pools and saline lagoons, with Titchwell and the ditches at Cley both favoured sites. Great Crested Grebes may join them at Titchwell but are more often encountered just off the beach, making use of our inshore coastal waters. Here they mingle with much smaller numbers of the other three species, providing birdwatchers with an opportunity to practice their identification skills.

The Great Crested Grebes leave their breeding sites in the autumn, seeking out larger waterbodies and coastal waters on which to moult, a process which leaves them flightless for several weeks. While several dozen individuals may gather at favoured sites, our wintering population is dwarfed by the 30,000 that moult and winter on the Ijsselmeer in The Netherlands.

Both Black-necked and Slavonian Grebes have small breeding populations in northern Britain (roughly 40-50 pairs each), which are part of a much larger breeding range. While some of our breeders may be among the birds wintering around the Norfolk coast, other wintering birds will have arrived from elsewhere. The size of the arrival is influenced by weather conditions across more northerly waters. All of the species that make use of coastal waters prefer shallow, sheltered bays, which is why Holkham, Holme and Titchwell seem to hold birds to a greater degree than other sites around the county. Here they feed on crustaceans and small fish, often feeding alongside Red-throated Divers and Cormorants.

During the hardest of the winter weather, when bitter winds deliver ferocious storms to our shores, the birds may be forced inland, affording birdwatchers easier viewing than is typically the case when watching these birds at sea. The winter plumages of these birds are dull in comparison with their breeding finery and separation of the different species requires an understanding of the physical structure of each species as well as the plumage pattern. It is worth the effort, however, when you can see all five in a single morning.

Wednesday 9 December 2009

The enthusiasm of naturalists


Nothing beats being out in the countryside with other naturalists, with people who are full of knowledge and able to deliver their enthusiasm for the natural world. There is so much going on in the natural world, so many different species that you always have a great deal to learn from others who have chosen to specialise on different groups to you.

Take botanists, for example; the other day I spent an afternoon at the Royal Horticultural Society garden at Wisley in Surrey. With me were Brett Westwood (a writer and BBC producer) and Paul Evans (a BBC presenter). Brett is an excellent all-round naturalist, but I suspect that plants are his true passion. Both men were positively bouncing around the garden, full of delight and comment at the range of ferns and plants that were now surviving out of doors, released from the glasshouse by a changing climate. Not only did they know the name of each of these objects of desire but they had a myriad of tales to tell about them. It was truly infectious and I kicked myself for never having got into plants; I have always preferred things that crawl, slide, hop or fly!

Brett gets out and about on a regular basis, turning up new records or rarely observed behaviours with a group of wildlife enthusiasts in the Wye Valley, and I have made similar outings around Norfolk from time to time. Bringing a group of naturalists to a site can reveal the presence of previously unrecorded creatures and the naturalists seem to feed off each other, sharing their collective knowledge in a truly practical way. This is an approach that has been put into practice by the Norfolk and Norwich Naturalists’ Society (NNNS) on a regular basis, with field meetings arranged to increase our knowledge of sites across the county.

One thing that is often missing from such gatherings is the presence of a younger generation, the naturalists of tomorrow who will pick up our magnifying glasses and maintain the knowledge needed to underpin future conservation efforts. Both NNNS and Norfolk Wildlife Trust have been working to develop this new generation by holding events at which youngsters can engage with nature. My own interest, although initially developed alone, gained momentum by being taken to such events by my father; he still refers to the fungus study day where we spent hours wandering a heath in the pouring rain. I have never been so cold or so wet as that day, and I suspect that neither has he!

Being a naturalist is all about retaining that childhood enthusiasm, the desire to find, identify and be fascinated by wildlife; perhaps that is why we bounce about so enthusiastically.

Tuesday 8 December 2009

Dry autumn leaves a legacy


While the wet weather of recent weeks may be sufficient to cloud the memory, clearing it of recollections of dry autumn days, a visible legacy of autumn’s ‘drought’ has been the poor crop of mushrooms and toadstalls. My weekly walks through mixed and broad-leaf woodland, across fields and heath, have turned up little in the way of fungal fruiting bodies. I would imagine that my experience has been repeated in those who take a more detailed interest in fungi than I achieve with my casual eye.

The building blocks of fungi are the fungal hyphae, thread-like tubes that occur in vast numbers in damp leaf-litter; scoop up a handful of this leaf litter from a damp deciduous woodland and you will soon reveal a cobweb-like mat of fungal strands. These absorb nutrients, either from the soil or from the substance in which they are growing (some fungi grow in and digest wood, while others tackle hair, feathers or the hard exoskeletons of insects). For the greater part of the year hyphae are hidden from view, held within the substrate, but come the autumn they may form fruiting bodies, the familiar mushrooms and toadstalls being one such type. The fruiting bodies allow reproduction and the formation of new colonies, as spores are released to drift on the wind.

Fruiting bodies are produced once the mat of fungal hyphae has reached a certain age or size. Development is then triggered by environmental conditions and research has helped to pinpoint what is involved in this process. In addition to nutrient availability, both soil temperature and humidity are important, with dry ground inhibiting production of the complex fruiting bodies. As anyone who has collected or watched a Shaggy Ink Cap will testify, many of the fruiting bodies are very short-lived (perhaps lasting only for a few brief hours or a couple of days). The tough, woody, bracket fungi, however, are much more robust, with some lasting for 20 years or more and adding a new spore-producing layer each autumn.

The process by which the body develops from the thread like hyphae is fascinating, with a quick progression from a knot of hyphae through to the ‘button’ stage (which is effectively a fully-formed but miniature version of the final body). The next stage is one of expansion, the use of hydraulic pressure increasing the size of the body and forcing it up through the soil’s surface. Such is the strength of the hydraulic pressure that fruiting bodies have been recorded lifting paving slabs and other obstructions.

It is easy to overlook the network of hyphae that drives the production of fruiting bodies but the lack of fungi this autumn is a gentle reminder of their function.

Monday 7 December 2009

The turning of the tide


It is the first really cold day of winter; a bitter wind driving in off the sea. We have come to Holkham Gap to search for Shorelarks, winter visitors from Fennoscandian breeding grounds that return to favoured traditional haunts in varying numbers late each autumn. Parking on Lady Anne’s Drive, earlier enough in the morning to be just a few strides from the beach, we wander out into the Gap and start scanning the exposed saltmarsh and sandy shingles for birds. Almost straight away we catch the movement of a flock of small birds. This is a mixed flock, mostly Goldfinches but with Linnets and Meadow Pipits among their number, wonderful to see but not what we have come for.

Moving to the east and skirting out towards the ridge of sand we soon come across another small party of birds, this time with nine Shorelarks in their midst, all busy feeding on seeds, including those from the Salicornia. Shorelarks are instantly recognisable birds, peachy-brown in colour with yellow and black head markings and delicate black ‘horns’. They have something of the exotic about them, a feel of the Mongolian desert that perfectly balances their preference for the short vegetation and rough ground that Holkham’s coastal shingles provide. As we watch, the larks move forward with an abbreviated mix of runs, shuffles and crouches, pausing to feed and then briefly disappearing from view behind the uneven ground.

Holkham Gap, Salthouse and Cley are Norfolk’s traditional sites for these birds, the mix of vegetation providing the cover and feeding opportunities that they need. There were few Shorelarks around last winter but this year things are looking better. The pattern of fluctuating numbers is not a new phenomenon and it has been suggested that the size of the autumn arrival is determined by the number pushed west during migration. The bulk of the Fennoscandian breeding population winters in northeast and central Europe and few birds cross the North Sea to our shores. Numbers are also influenced by what has been happening to these birds on their breeding grounds, with the increasing population in southern Norway likely to see increasing numbers wintering here in the future. There are probably several dozen birds here this winter, far fewer than the extraordinary flock of 240 present on 28th November 1998.

While these birds are fleeting visitors to our shores, they have a truly extraordinary global distribution. Widespread across northern Europe, Asia and North America, there is an isolated breeding population in Chile and one in Morocco’s Atlas Mountains. Breeding has even been attempted in Scotland. As winter progresses, the larks will be harder to find, becoming shy and retiring, with some birds moving off to the Continent.

Saturday 14 November 2009

A sense of scale


There are parts of the Norfolk landscape that feel remote and isolated from the workings of Man, stretches of coast where a bleak solitude can be found amid the dull tones of saltmarsh and the grand winter skyscapes. It is at this time of the year that these stretches of coast offer up their charm, the last of the holidaymakers now tucked up at home and only the hardiest of souls tempted out on a day when the bitter winds drive in off the sea. It is a good time to be out and about, to take stock of the summer’s achievements and to reflect on seasons past.

Here, in Norfolk, it is the limitless horizon of the North Sea that delivers the special sense of place that I get from certain landscapes. By stretching away to meet the sky, it removes the sense of scale that seems ever-present elsewhere within the county. This landscape ‘on the edge’ moves me in the same way that I am moved by the great granite hills of northern Britain, the bleak moors of the west and the ancient chalk escarpments of the southern downlands. These are old landscapes and to be within them, part of them, reaffirms my place in the land.

The coastal saltmarshes, which echo to the haunting calls of Redshank and Curlew, are a fragile habitat, sensitive to changing sea levels internationally and increasingly squeezed in between the sea and prized arable land. Within Norfolk, however, the expanse of saltmarsh, which starts in the west at Thornham and stretches east as far as Cley, is largely protected from the direct impact of the sea by extensive shingle ridges and sand dunes. In recent years the defensive sea wall has been allowed to breach in places, part of a process of managed retreat.

The power of the sea is something that remains very difficult to deflect. Over the centuries the coastal fringe of Norfolk has been subjected to inundation, with periodic storm surges (or ‘rages’ as the Victorians called them) dumping huge quantities on sea-water onto fresh and grazing marshes, changing the shape of the coast and impacting upon the lives of those who make their living there. It is a reminder that we do not exert complete control over the world around us, that there are natural processes that will shape the way in which we live.

Being here, at this boundary between land and sea, shedding the sense of scale, underlines the fact that we are part of a wider world. It removes us from the comfort of our day-to-day lives, something that it is difficult to do in our increasingly busy world.

Friday 13 November 2009

The great arrival


At first it seemed as if it was a thin strip of cloud, a blot on an otherwise clear horizon. Far out above the sea, but still visible to the naked eye, this grey smudge was stretched, elongated along the horizon like a fuzzy line left by a soft-leaded pencil. Over the course of next forty minutes the shape changed, its strength of colour dissipating as it drew nearer towards me. Through my binoculars I could now see individual outlines within the great mass, a great skein of geese nearing the end of their autumn migration and their arrival on our coastal grazing marshes.

The flock was no longer heading straight towards me but would make landfall to my west, a mile or so along the coast. I was too far from the car to be able to make it to where these geese would cross the coast, perhaps then heading inland to one of the many fields they would use over the winter months that lay ahead. The flock itself was composed of a number of separate skeins, each containing several dozen birds. These were pink-feet, visitors from breeding grounds in the wilds of Iceland and eastern Greenland.

It is a tremendous journey that these birds undertake and it is humbling to think that so many arrive to winter here in eastern England. The importance of the Wash and the North Norfolk coast is underlined by survey figures published by the British Trust for Ornithology. These show that some 60% of the UK’s wintering population of Pink-footed Geese spend the winter along this bit of coast. Other concentrations can be found wintering in Scotland and Lancashire.

While I have missed the landfall of these particular birds, there will be other mornings on the coast when the geese will be seen. Later into the winter these will be birds not arriving, but moving between overnight roost sites and feeding areas inland. Then there will be the spectacle of a field of geese, hundreds strong, feeding on beet tops and waste potatoes. These grand flocks of pink-feet sometimes hold other geese, scarce visitors like Tundra Bean Goose, Greenland White-fronted Goose or Snow Goose. These days it is becoming increasingly difficult to know whether some of these birds (notably the Snow Geese) are genuine vagrants or part of an expanding feral population. Even if individuals are seen to arrive with the pink-foots, they may have joined them on some Scottish staging area.

There are some wildlife spectacles that are both a ‘must see’ and accessible. The sight of a large flock of pink-feet is certainly one of these. Make a trip to the coast one weekend soon and experience it for yourself.

Thursday 12 November 2009

Ring-tails much in evidence


It has been one of those little runs, where each birdwatching trip has turned up a species that I do not often see. Over the last three weeks it has been the Hen Harrier, with one or more individuals seen on each occasion that I have been out on the coast. First it was Blakeney Point, with two birds working the dunes beyond halfway house. Then it was Titchwell, again two birds but this time hunting the marshes out towards Thornham and, most recently, it has been Cley, with a single bird working the sea wall for Meadow Pipits and, quite possibly, Snow Buntings.

For me, the Hen Harrier is a bird of winter afternoons, watched coming in to roost at Stubb Mill or Warham Greens. To see them so well this much earlier in the year is a welcome bonus, a little run of good fortune.

The Hen Harrier last bred in the county in 1861 (at Horsey) and is now a passage migrant and winter visitor. Its changing fortunes mirror those over the country as a whole, a species that was once widespread but taken to the brink of extinction in Britain because of intense persecution. Breeding Hen Harriers take grouse chicks, along with Meadow Pipits, Skylarks, voles, Rabbits and young waders, and have therefore been shot, trapped and poisoned by generations of gamekeepers. As has been the case with other persecuted species, the population recovered somewhat in the 1940s but even now, with legal protection in place, it remains heavily persecuted. Its loss from its few English moorland breeding grounds for a second time remains a real possibility. Even on its wintering grounds the Hen Harrier is not safe from persecution; two were shot coming in to a roost in northwest Norfolk in the 2007/08 winter.

Those individuals that winter in Norfolk come from breeding populations in Wales and Scotland, joined by smaller numbers of birds from the Continent. Arrivals begin in September, peaking in October with further influxes later into the winter if weather conditions on the near Continent push birds further west. Perhaps a dozen or so favoured roost sites are used, the birds roosting communally on the ground in reeds or other vegetation. Research has shown that most roosts contain between two and 10 birds, often with other birds of prey present (such as Marsh Harrier and Merlin) but some can hold up to two dozen birds. As well as roosts along the North Norfolk coast, others can be found in the Brecks, the Fens and the Broads. Many birdwatchers visit the better-known roosts towards the end of a day’s birdwatching but seeing these magnificent birds on a crisp late autumn day is infinitely better.

Wednesday 11 November 2009

A flurry of Snow Buntings


The other morning I was treated to an enthralling display by a small flock of Snow Buntings. The birds, flashing a blizzard of white wing and tail markings, rolled as one as they twisted and turned above one of the lagoons at the RSPB’s Titchwell reserve. At first I was not sure what they were up to, the flock sweeping low to the water almost as if the buntings wanted to land. These are small birds (only slightly bigger than a House Sparrow) and, with no wading birds close by with which to judge the depth of water, I could not imagine that this is what they were attempting to do. Perhaps the buntings themselves were unsure, this would explain the hesitant passes low to the water, but then, suddenly, three birds broke from the flock and landed, the others sweeping back around to join them. The buntings had revealed the water to be far shallower than it appeared from my position on the bank and I had to smile at the way in which these delightful birds had broken that particular optical illusion.

These Snow Buntings were not the first of the winter and I had encountered other groups over previous days, notably at Cley and on Blakeney Point. Here the birds were in more characteristic habitat (for the winter), foraging on the ground amongst the sparse vegetation of the sea wall. This winter preference for our coastal fringes contrasts with the high montane breeding grounds, located high in the Scottish Highlands or further afield in Iceland and Greenland. The Scottish breeding population is small, but thought to be self-sustaining, and is thinly scattered over a wide area. Here the birds nest among boulders, located close to long-lasting summer snow fields.

Snow Buntings are to some extent nomadic and the numbers wintering around the Norfolk coast can vary substantially from one year to the next. Ringing studies have revealed an exchange of birds with the Low Countries and there is even a record of one reaching northern Italy.

One of the most engaging things about a feeding flock is the way that they maintain a steady, almost conversational, trill as they feed. They are also fairly tolerant of a human observer. When viewed as a single entity, the flock seems to roll across the ground, as individuals dash to the front to search new ground for seed. Another feature of these flocks is the way they just disappear into the background, their patterned plumage providing effective camouflage on the shingle. You can watch a flock fly in, dropping down onto the shingle not 30 feet from you, and then you struggle to pick them out. Once you have found them, however, they are magical.

Tuesday 10 November 2009

Renewing an acquaintance


It was mild night, the almost complete blanket of cloud helping to retain some of the unseasonable daytime warmth; warmth that would dissipate rapidly into a clear autumnal sky. The cloud had plunged the wood into darkness, thickening the shadows and hampering our attempts to erect fine nets without resorting to the light of our headtorches.

We were here to catch a Tawny Owl or two, luring them into our nets with taped territorial calls. Choosing a likely spot within the narrow finger of woodland, we set two nets in a dogleg, placing the tape machine in the angle where the two met. Once the tape was running, broadcasting the territorial hoot of a male Tawny Owl, we retreated further into the darkness to listen and wait. The distant drone of cars carried across the lakes, disturbing what would otherwise have been a perfectly still night. Even so, the wood was alive with sounds: delicate rustlings among the leaf litter that could only be mice or shrews, stirrings from the wildfowl at roost and a distant series of whistle-like notes that may have been one of the local Otters. What there was not, however, was any sign of an owl; we would need to reposition our net.

A little later into the evening, and with the cloud starting to break up, we found ourselves in another piece of woodland, nets in place and tape running. Here, larger animals were abroad: Badgers pushing through the stands of now dying Bracken, murmurings of Jackdaws, roosting nearby and a few soft calls that could (just) have been an owl. The tape had seemed too quiet all night, frequently stopping unannounced, and we’d discussed the need for better equipment before we next ventured out ­– this had been something of a test run in any case. After half an hour without response we decided to call it a night.

It came as something of a surprise, then, to find a Tawny Owl sitting in the bottom shelf of the net. She was beautiful and quite calm as we lifted her clear. The owl already sported a metal ring, complete with a unique number that identified her as an old friend ­– the female from a local territory. Having measured her wing (which gives a measure of structural size), we weighed her and examined wing and tail feathers for signs of moult. Subtle differences in the colour and pattern of individual feathers showed that she had feathers from three different generations ­– Tawny Owls only moult a few of their flight feathers each year. She was looking fit and well, ready for the breeding season ahead, and she quickly slipped back into the darkness as we let her go.

Monday 9 November 2009

Master of the skies


It’s an exhilarating sight, a Peregrine working the coastal grazing marshes with a display of unrivalled skill and power. It is the reaction of a small flock of Golden Plover that first alerts me to the presence of this master of the skies. As is so often the case, it is the waders that first spot the approach of a predator and take to the air in a close formation that jinks through the sky, flashing different colours as the birds twist and turn in unison. The reaction spreads, as first Gadwall and then Wigeon take flight, the departure of these larger birds suggestive of something bigger and more powerful than the harriers that are the resident hunters above these pools and reeds. It only takes a moment and then I am onto the bird, following it in my binoculars with relative ease as it dives and then rises again in a sweeping arc, powered by strong wings.

There is something truly spectacular and totally engaging about a winter Peregrine working the marshes. Perhaps it is the amount of sky visible above our relatively flat landscape, the expanse of blue and grey providing a suitable canvas on which this stunning bird can exhibit its skill. A bird such as this one will cover some distance, sweeping along the coast towards the Wash, harrying the wildfowl and waders with immaculate ease. This is a top predator, quite capable of bringing down a Herring Gull or Mallard, though more usually taking somewhat smaller prey, such as Black-headed Gull, Lapwing and Redshank. Some of these lowland coastal birds will also hunt inland, working over farmland to exploit our growing Wood Pigeon population. In this respect they are welcomed by many, though Peregrines that harass racing pigeons are one of the main sources of friction between conservationists and those who indulge in pigeon racing.

The return of Peregrines to many former breeding sites has been matched by an increase in the number of birds wintering around the Norfolk coastline. Even so, we are only likely to be talking about a relatively small number of birds that will remain here over the winter. To see just one of these birds in action is a privilege and something that brightens even the coldest, most windswept of November days. This particular bird is working hard and is clearly focussed on securing a meal. Even so, it fails to catch anything in the few brief minutes that it remains in my field of view. Working its way west, and becoming all the more distant, I suddenly lose the bird against the dark outline of a field. It is gone, the moment passed, but there will be other moments and other Peregines.

Saturday 17 October 2009

Light and shade


The clearance of a large block of mature pine has changed the mood of the piece of secondary woodland through which I walk most mornings. The wood had always been a dark and brooding place, surrounded as it was by ranks of alien conifers. The darkness was intense, pressing up against the narrow path that ran in a straight line towards the faint glow of a more open forest ride at its end. The wood also carried a stillness, fathoms deep and broken only by the occasional call of a Robin or the scuttling feet of a Grey Squirrel as it scrambled up a nearby trunk, alarmed at my arrival.

With so many blanketing conifers removed, much of the wood now feels light and airy, the path seems wider and the whole place less threatening. The additional light has stirred ground vegetation and this spring there was a carpet of green, a rush of life quick to claim the newfound source of light and warmth. More birds have appeared; Song Thrushes which raised a brood of chicks, encountered early one morning sat about the path, undeterred by my arrival and choosing instead to beg for food. The parents would have done well here this spring, the damp ground of the shaded rides providing access to an abundance of invertebrate food and a plentiful supply of banded snails for when the heat of summer made other invertebrates harder to find.

Several Chiffchaffs set up territories along the edge of the wood, their onomatopoeic song one of the first signs of a bountiful spring. Now, in early October, extended parties of tits (with the occasional Chiffchaff or Goldcrest in tow) can be seen passing through the wood, searching for food among the branches and those leaves that have yet to turn and drop in the first of the autumn’s storms. Two Roe Deer hang about the edge of the wood most mornings, moving quickly away to what they perceive to be a safe distance before turning to watch me pass. They are inquisitive animals, rarely disappearing blindly, and I like to see them about the forest. To me, they seem more ‘deer-like’ than the squat, dog-sized forms of the introduced Muntjac that are present in greater numbers.

A sense of the old wood remains, where it butts up against the block of plantation too young to cut, but my feelings towards this shadowy presence have changed. It is no longer threatening or unknown but a welcome pool of darkness in a now more open landscape. Writers sometimes describe the balance of light and shade, relating how one enhances the other; here in the wood I have come to understand what they mean.

Friday 16 October 2009

Porpoise encounter


Norfolk’s extensive coastline offers a fair number of opportunities for seawatching, an increasingly popular pastime among local birdwatchers. Hunkered down on a blustery autumn or winter morning and scanning with binoculars for passing seabirds that have been driven close to shore by the stiff winds, it is hard but sometimes rewarding work. Identifying distant birds, as they dip and rise between the waves, is something of an art form and I still have much to learn. The worse the weather, the harder it is to identify passing birds but the harshest weather often delivers some of the best birds close inshore.

Seawatching earlier in the year, under the calmer conditions of early autumn, can be more rewarding in that you tend to getter better views of things and don’t have to endure such biting winds. The other weekend we spent an hour or so seawatching at Winterton. It had been a quiet morning in the dunes for passage migrants (save for the Red-breasted Flycatcher skulking in some thick scrubby cover) and we decided to see what the sea could offer. In addition to numerous Cormorants, passing flocks of Eider and Common Scooter, there was the rewarding sight of a Harbour Porpoise making its way slowly south just 200m off the beach.

The Harbour Porpoise is our smallest cetacean (whale or dolphin), measuring in at about 1.5m in length. Less boisterous than a dolphin, the Harbour Porpoise only rarely leaps from the water, instead moving with a rolling motion, the small triangular dorsal fin just clearing the water’s surface on a round back. When the sea is much rougher they may surface rapidly, which can result in them clearing the water to breathe. Most are seen singly or in small groups of 2-10 individuals and they can be highly mobile. Satellite tracking studies have revealed that the males range further than the females and can easily cover more than 50km during the course of a day. Although they are present in our waters throughout the year, sightings tend to peak between July and October, which may either reflect recording effort or a genuine seasonal pattern to the use of our coastal waters.

Numbers are likely to have changed over longer periods of time as well, as changes in fish stocks, increasing levels of disturbance and increases in sea temperature influence distribution and population size. Unfortunately, there is a great deal still to learn about Harbour Porpoises and our lack of knowledge leaves them open to various threats (such as fisheries bycatch). Because of this sightings are urgently needed; if you see a porpoise around the East Anglian coast download a recording form from the reports and publications section of www.norfolkbiodiversity.org and make your sighting count.

Thursday 15 October 2009

Don't dismiss sycamore out of hand


First introduced to Britain during the 16th Century, the Sycamore is a tree that is often dismissed as being of little value to wildlife. Many of those involved in nature conservation refer to it as a ‘weed’, spending hours pulling Sycamore seedlings that have established themselves in some piece of ‘natural’ woodland. Gardeners are also deterred by the huge numbers of seeds that are produced, each one a miniature marvel of aerodynamic efficiency, not to mention the leaves which attract large numbers of aphids and their sticky residue.

It is the production of so many seeds, together with their efficient dispersal mechanism, that has made the Sycamore such an effective colonist. Tolerant of salt spray, the Sycamore has even become established on dune systems around parts of our coastline. Its tolerance of pollutants has also enabled the Sycamore to establish itself within larger urban centres, where it can be found lining railway embankments, depositing ‘the wrong sort of leaves’ onto the nation’s railway tracks.

The Sycamore is capable of rapid growth, which is one of the reasons why it was so favoured for introduction to the great landscaped parks that were a feature of the 18th and early 19th centuries. This growth, coupled with the dense shade cast from the canopy, supports the perception that the Sycamore is an invasive species capable of shading out native trees within broad-leaved woodland. Conservationists feared that their native woodlands would be replaced by monocultures of Sycamore, impacting upon wider biodiversity because the tree supports only a small number of plant-feeding invertebrate species. Interestingly, however, the Sycamore actually delivers the greatest insect productivity, in terms of weight, of any widespread tree, even beating the mighty oak. Admittedly, most of the biomass is made up of aphids, but these are likely to be an important food source for birds and other creatures, particularly in urban areas and at certain times of the year.

Sycamore also has an economic and cultural significance. Not only is it fast growing but the wood it produces is clean, pale, with a fine grain and no real odour. This makes it an ideal wood for woodturners and for the production of wooden products for the kitchen (such as bread boards and rolling pins). There are a number of mature Sycamores of cultural importance, perhaps the most famous of which sits on the green in the village of Tolpuddle. It was under this Sycamore that the Tolpuddle martyrs held their union meetings during the 1830s.

Like many others, I remain in two minds about the Sycamore. It is an introduced species and one of the ’big seven’ invasive plants but it does deliver some benefits that may not be obvious from a cursory glance.

Wednesday 14 October 2009

Nomadic ibis visits Norfolk


The Tas and Yare valleys contain some of Norfolk’s less accessible stretches of river and riverside marshy ground. The degree of isolation – the rivers passing through areas of privately owned land and lacking public rights of way – has made it difficult for local birdwatchers to catch up with one of our more engaging visitors of the autumn, the Glossy Ibis. Over the last few weeks several of these birds have appeared in the county, seemingly favouring the marshy ground to the south of Norwich. They are part of a much larger arrival of these rather odd looking birds, which are more usually encountered in parts of southern Europe and Africa.

The arrival stems from the nomadic behaviour that is seen after the end of the breeding season, with young birds in particular prone to wander over large distances. The species itself has a very wide global distribution but breeding populations within Europe have been, until recently, rather small. That in southeast Europe has been in decline, perhaps reflecting the degradation of favoured wetland habitats, but this is in contrast to the expanding population now established in southern Spain. It is likely that the individuals seen in Norfolk over recent weeks have come from the Spanish breeding colonies, even though this population has traditionally been largely resident rather than migratory (as happens with certain populations elsewhere).

With a strongly down-curved bill, the Glossy Ibis has been described as looking like a cross between a Curlew and a heron. The deep maroon plumage, which can appear black in poor light, contains brighter areas of green or purple sheen and a breeding adult is a particularly attractive bird. It is similar in size to the now familiar Little Egret and noticeably smaller than a Grey Heron, with a distinctive silhouette when seen in flight. Small groups of Glossy Ibis often adopt the habit of flying in a trailing line. Habitat-wise, the species prefers to feed in shallow water, typically the marshy margins of inland lakes and rivers. Here it will feed on various insects, crustaceans, molluscs, amphibians and, occasionally, fish. The diet seems to reflect what is available in the locality and it also varies with season. It is less often encountered on coastal marshes. The feeding areas are often some distance removed from those sites used for roosting and this provides an opportunity for the birdwatcher to pick up the ibis as it flies between the two in early morning or late afternoon.

Catching up with this bird in Norfolk is not easy, even in an autumn with an influx as large as this one, but you never know. Keep your eyes peeled, especially if on the train from Norwich to Lowestoft or Yarmouth.

Tuesday 13 October 2009

We must learn to love insects


I recently attended a conference on insect biodiversity in gardens, organised jointly by the Royal Horticultural Society and the Royal Entomological Society. It was an opportunity for those of us working in the area to share our knowledge and to stimulate discussion on the importance of insects within the garden environment.

Most readers of this column will have a garden and most will also, at some level, engage with at least some of the insects that call the garden ‘home’. However, the form of this engagement is likely to vary dramatically, depending upon the gardener and the species of insect in question. Mention butterflies and bumblebees and you are likely to receive a positive reply (butterflies are honorary birds in many peoples’ eyes), but mention caterpillars and wasps and you’ll very likely get a different response.

Pippa Greenwood, who introduced the conference, picked up on this and noted how insects in general have something of an image problem; the sight of a ‘bug’ so often prompting a ‘yuk’, ‘urgh’ or ‘what is that horrible thing’ response!  The question of whether this loathing of insects was something innate or learnt was discussed; the general feeling among the audience being that since young children seem excited by the sight of some marvellous bug, it must be learnt. Are we, as adults, teaching our children a mistrust of insects because of some parental fear that an unknown insect might bite or sting? If so, then the problem is one of education, of helping people to recognise and appreciate insects for what they are. So few adults actually take the time to look at insects up close; they dismiss them out of hand. This is such a shame and suggests to me at least that they have lost that sense of fascination that we all once held as children. See a dung beetle up close and you cannot help but smile at its cumbersome movements or fail to draw a comparison with the solid form of a rhinoceros. Watch a tiny jewel wasp and marvel at the dazzling colours that adorn its body, colours that change with the angle of viewing.

One of the real contradictions to our lack of understanding of insects is that they remain one of the most readily accessible groups, living alongside us in our houses and gardens in great numbers. You don’t have to go anywhere special to see them; all you need is a hand lens (to do them justice) and some patience. Insects are of vital importance, supporting a vast food chain and pollinating our crops, so it is essential that we come to value them more highly. We owe it to our children to engage with them on more positive terms.

Monday 12 October 2009

Red Deer roar in the forest


Autumn has settled upon the forest, delivering a scent of decay, a change in the colour of the vegetation and a noticeable dip in temperature first thing in the morning. While these changes mark the end of summer and herald the approaching long dark winter months, they bring with them a freshness that is both uplifting and energising. There is a real sense of transition, a renewal if you like, as plants shed waste accumulated over the summer and direct resources towards next year’s growth. The animals are also preparing for the winter ahead, laying down fat reserves and, in some cases, getting down to the business of breeding, initiating a process that will see young delivered just as spring erupts in a burst of new growth.

Red deer have started their annual rut and the early morning forest soundscape now carries the soft, bewitching roar of a distant stag. There is something very primitive in the stag’s evocation, heard at dawn in a forest landscape draped with tendrils of mist. It is a sound that hints at unseen mystical creatures, haunting the edges of vision and the shadows that sit deep within the dark ranks of conifers. The roar is part of a wider ritualised display; mature males also thrash vegetation, wallow and anoint themselves with urine. The frequency and duration of roaring has been found to indicate the dominance of the individual, with the dominant stags the most vocal.

Stags leave the bachelor herd in September to seek out hinds, favouring traditional rutting areas from which they will attempt to round up hinds into a harem and then retain access rights over other stags. My local patch appears to have just a single roaring stag this year, calling from slightly further west than the three heard in each of the last two winters. Perhaps this is a consequence of the clearance work that has been carried out in this part of the forest. Rival males may follow up the roaring contest with ritual display, walking side by side in an attempt to size one another up before (sometimes) escalating the contest to a more physical challenge. Individuals may fight by locking antlers, pushing and twisting with their powerful bodies in an attempt to gain the upper hand and force the other to concede defeat. Serious injuries and deaths are not uncommon. Access to a group of hinds is the ultimate prize and, following successful mating, the females will deliver their young at the end of May or start of June.

As summer comes to its end, the forest’s Red Deer are beginning a new cycle; the roaring males the signal of something promised by this time of renewal.