Nature 2007 December

What’s black and white but read all over?

Looking back at September and October’s weather we see a shift from cooler, wetter spring and summer weather patterns to a milder, drier autumn season. There was little more than an inch of rain in the months of September and October and November has started in much the same way. The outlook for December and January is for a mild winter with less rainfall than the average of the last ten years although perhaps a little wetter than last winter.

Nature’s autumn colours – the reds, yellows and browns have largely given way to nature’s winter and its shades of black, white and grey. Take a stroll or even look out the window any bright morning around now and you cannot fail to appreciate why artists favour this time of the year for those shafts of slanting ‘winter light’. The polarising of the light adds a distinctive quality to subjects for painter or photographer alike. Everything in view, from an awe-inspiring landscape down to just a few blades of frost-scarred grass seem to be magnified, their otherwise overlooked features now sharply in focus.

Spring and summer are the seasons where perhaps the need to propagate is the chief driver of wildlife activity. Falling temperatures and the shortening day length condition wildlife to concentrate their search for food over shortened sessions and seek shelter for the majority of time.

Black and white long-tailed tits, despite that blush of reddish-pink they also display, are unconcerned it seems by attracting attention. Groups of 10-20 seem conjoined somehow by an invisible elastic thread as they noisily process from tree to tree in search of invertebrates and occasionally seeds and wizened fruits that remain ‘in situ’. Meanwhile great spotted woodpeckers monochrome save a red punk ‘Mohican’ frequent our peanuts.

The lapwing is one of the more distinctive resident birds. Visually, with its ‘brylcreemed’ crest and black and white wings it makes a spectacular, synchronised, semaphore display when taking off en masse from a field. Audibly its high-pitched piped call, as though the admiral of the fleet was being signalled on board, provides one of its alternative names – Peewit. Although, sadly, there has been a decline in numbers, 42% since the seventies, there are moves underway to help with grants being provided to landowners and to farmers, for whom in return, it provides a service by removing infestations of leatherjackets and flukeworms from sheep pasture. There are records of one or two pairs nesting on arable land in St Leonards during the 1990’s but none recently. If you are very lucky, you may catch a glimpse between autumn and spring of them en route between upland arable fields and the wetland areas around Tring.

Holly, a common occurrence in our beech woods, is one of the few sources of bright colours at this time of year. It is dioecious, i.e. separate male and female bushes, with only the female bushes resplendent with red berries. Our woodland once ran with pigs in the autumn and holly was nurtured as an impenetrable boundary, keeping the porcines in and poachers and predators out. Holly was also an important source of fuel. Only the younger leaves have thorns though – pointing alternatively up and downwards – and strengthened by thickening of the cell walls. The newer leaves contain the most nutritious materials for deer and have, through evolutionary pressure, developed thorns to protect it from overgrazing. The holly has further refined this evolutionary reaction by progressively recycling the valuable reinforcements from older into the young leaves.

Both black and white bryonies are ‘December’ plants, showy this month but inconspicuous for most of the year, they creep through hedgerows. But despite the name they are otherwise unrelated. Neither has leaves on display this time of year but the black variety furnishes red berries and the white has pale scarlet berries, is related to water melon and also goes by the name of ‘English mandrake’.

Squirrels build their winter drays this time of year, visible in the crux of trees. We are not, of course, blessed with red squirrels in the Chilterns anymore but the grey squirrel which drove them out, does occasionally sport a black variety and near here is where the black melanic variety was introduced into Woburn Park at the end of the 19th century, and they have spread along the Chilterns since then.

Ponds also reflect the winter scene, the dark beneath the surface. Everything slows to a near stop during the cold period but the carnivorous insects such as dragonfly larvae do feed periodically. Another invertebrate, the water spider, in summer rests up during the daytime in a bubble of air it has gathered at the surface and pulled down trapped in a silken web, which is then spun in the water plants. After dark it gathers around its hairy abdomen sufficient air to set off and hunt. In winter it may remain within its silken cocoon or use empty snail shells sealed with silk.

Any account of black and white is not complete without mention of badgers. Their name is derived from becheur, the French for ‘digger’. When available they have been known to excavate up to 200 earthworms in a single night. Badgers remain active throughout the winter although pregnant females retreat to their setts in January to give birth to their cubs.

Time to suggest some more Christmas gifts, this time for children. First, the delightfully titled ‘Under One Rock, Slugs, Bugs and other Ughs’ by Anthony D. Fredericks or ‘The Horrible Science Annual 2008’ by Nick Arnold and Tony De Saulles. As an alternative, how about a subscription to ‘Buglife’ the charity for invertebrates – www.buglife.org?