Nature 2009 December

Otherwise obscured or easily overlooked

“Having wandered through woods for several miles, the lane suddenly came to the open, and I found myself on an open escarpment of the Chilterns, a country so familiar…” J.H.B. Peel (1970)

The Chiltern scene at this time of the year confirms that the familiarity with which Peel talks about is not just a singular experience to be enjoyed only in spring or midsummer, such as one might experience in an equatorial rainforest where the seasons are unchanging. The Chilterns may be described for the tourist as verdant woodland and pasture but the winter season affords contrasting views of beige through to brown and at times provides the only chance to see the flora and fauna around us which may be otherwise obscured or easily overlooked.

Take the simple example of birds’ nests. Built to survive the rigours of the weather and to avoid being discovered, they remain largely undisturbed hidden by leaves. With hedges and trees stripped bare this is the only time of the year when the intricacies of design, construction and disguise can be seen. Low down in a bush maybe a wren’s nest, a woven tapestry of leaves, moss and sedge or grass. Higher up, a long-tailed tit’s bottle-shaped dome remains entwined in the blackthorn thicket, held in form by the tension of slender twigs and spiders silk. In contrast, swaying in the highest boughs of the stand of beech trees, are the tatty remains of more haphazard nest-building by rooks and crows. The latter will already be hard at work rebuilding theirs, the former soon to follow their industry.

Mammals of all sizes need to steal some of the shortened daylight hours to forage for food or trap prey and are more likely to break cover and be seen and disinclined to seek cover if disturbed when feeding.

There may be over 900 species of moss in the UK. Perhaps we have over 100 in this part of the Chilterns: all on north-facing surfaces. Somehow overshadowed by the tree canopy they remain all but invisible to our senses for most of the year. Now unhindered by leafy boughs the woodland floor is flooded with bright direct sunlight in December and January. Taking advantage of this, mosses make the most of the next two months with vigorous growth, and replenishing their stores of energy. Within a few days they will transform from the dullest to the brightest shades of green, for this short period the most distinctive feature in an otherwise almost monochromatic wood.

You may not have spotted them straightaway but once encountered, others may come into sight, tucked away in a crevice, maybe a door or window jamb. It seems to be one of those winters when the bumper crop of late-season ladybirds are set on making our houses their temporary quarters. Regardless of the willingness of some of us, their hosts, to tolerate and accommodate them, our centrally-heated homes do not provide the right conditions for these beetles to survive the cold season. In their natural environment they would hibernate right on until at least April, unless spring comes earlier in late March. Inside, the artificial climate will stir them into activity too soon, perhaps as early as mid-January before there is any prey, typically aphids, for them to eat. As a consequence they will starve to death. So for the kinder-hearted amongst you, the best advice is to evict the ladybirds, thereby encouraging them to find an alternative hermitage.

My reference book advises on the use of a pooter, a peculiar device: a Victorian invention still used today by entomologists who suck up small insects via a tube into a specimen jar. I suspect this is not a device you have to hand, in which case a tickling stick in the form of a small brush or cottonbud will disturb the beetles sufficiently to encourage them to relocate to suitable place. A superior hotel for insects can be made from a bundle of foot long, hollowended bamboo sticks. In true ‘Blue Peter’ tradition a wholly satisfactory alternative motel-standard home can be constructed from a plastic lemonade bottle cut top and bottom and the cylinder filled by a length of corrugated cardboard, rolled up and stuffed loose enough for the insects to come and go freely. Ensure that the cardboard is sitting well inside the bottle with none left hanging out. If it gets damp the insects won’t use it. Having encouraged your visitors inside, mount the bottle in a tree or tuck into a south-facing wall, pointing slightly downwards to allow any moisture to drain out.

I end on something off-beat though entirely in keeping with the theme. For a seasonal topic I thought what, at this time of year, might one all too frequently stumble over on a walk around these parts? What frequently lies beneath our feet in some quantity at this time of year? I mean all that glorious mud which reliably confronts us wherever we choose to stroll and, despite our best efforts, returns homeward with us. I am assured that wherever it occurs it is of a unique composition and true reflection of the place in which it lies, comprising not just inorganic minerals but the organic remains of the particular plants that grow nearby and the animals that pass over or through or fall into and get trapped.

It’s the sort of stuff that TV forensic scientist Grissom could pin down within a few metres. So as elsewhere, in this part of the world there is a peculiarly Chiltern ooze within which there will be a high proportion of tree leaves; particularly beech, shards of bracken frond, fruits such as hawthorn and sloe at some stage of disintegration. On top there will be the tracks of muntjac, badger, fox, pheasant, horse or human. However, it is also a living habitat for local invertebrates; worms, beetles and centipedes as well as fungi and bacteria. Now while some of the detritus will have disintegrated or dissolved beyond recognition, it will also contain, trapped in the uppermost layer, this year’s deposits yet to be consumed by those invertebrates or dissolved by fungi. A contemporary fossil if you like. Mud is what Peel describes as a ‘chiaroscuro’ of colours and textures and just another reflection of the Chiltern country so familiar.

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