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 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.