2 That Time of Year That time of year thou mayst in me behold When yellow leaves, or none, or few, do hang Upon those boughs which shake against the cold, Bare ruin’d choirs, where late the sweet birds sang. ‘Sonnet 73’, William Shakespeare You would think, wouldn’t you, that the logical and proper place to start was January: the freshly washed face of a new year? But in all due deference to the double-faced Roman god Janus, the god of beginnings and transitions, I must point out that his month is of rigidly human designation and precious little to do with nature. It misses the plot. Whoever plumped for naming it was not thinking seasons or wildlife or weather, or even, with months of winter yet to endure, the human spirit. January may be the beginning of the Gregorian calendar year, but it is hardly a month of transitions. It straddles the plunging nadir of the Highland winter; it records our most gripping frosts down to –25º Celsius when diesel fuel turns to jelly, your skin instantly sticks to metal and, of course, January snows, from a powder dusting to drifts of three feet, are always just around the mountain. Even in mild winters when a warm Atlantic airstream clashes with a front of Continental cold we are raked by sudden storms of swirling sleet, despite the most valiant efforts of the Gulf Stream, huffing and puffing like the big bad wolf on the western side of the mountains. Not much transition there. January is when the chimney moans as south-westerly gales howl through the trees and hammer at our door. It is the month of brief, crimped days when the dogs won’t stir from their baskets; the month of thick gloves, neck-hugging scarves and fur hats, of tightly drawn curtains and glowing firesides; it is the month of hunkering down and staying put. Many mornings I have arisen in the dark, peered out of the window into whiplash sleet or icy rain squalls so fired with spleen that I have chosen to crawl back to bed rather than face the world. Neither, of course, is it the beginning of anything but the eponymous month. So, to do justice to nature, the nature of this mystical land of hills and glens, forests, lochs and rushing rivers, and to the confused seasons of what has proved to be a discomfiting and bizarre year, I need to start at a real transition, in late September when fidgets of swallows were gathering on telephone wires like chittering clothes-pegs; when the first tug of departure was fizzing in blackcaps’ tiny brains; before moonlit frosts cantered rust through the bracken; before the chlorophyll finally bled from blushing leaves; even before the last osprey lifted and wheeled into its long migration to Senegal or the Gambia. I need to start when the word was fresh on our lips, in the incipient, not-quite-sure-if-it’s-happened-yet autumn of 2012. Autumn may arrive slowly, but it gives itself away. Something ethereal arrives in the night, some curious edge to the breeze, some abstract quality of the breathed air, so that when you step outside you just know in your bones that the whole world around you has shifted its focus from summer and is now interested only in preparing for winter. It is a climacteric, a moment of physiological and psychological shift in nature’s thinking, especially for the birds. Summer birds depart, winter migrants begin to arrive. In the Highland glens, bird numbers plummet as their food supplies – natural fruits and every kind of creeping, crawling, slithering or flying bug – begin to disappear. Not just the swallows and house martins have vanished from round the houses. Gone are the insect-snatching wheatears, whinchats and stonechats from the hills; redstarts and flycatchers have fled the woods. Pied wagtails no longer flicker across the lawns, while sand-pipers and grey wagtails have deserted the riverbanks. Farmland and hedgerow species have vanished in the night: the linnets, yellowhammers, and all the warblers have decamped from the thickets. By the first frosts the hills will have emptied to a few hardy stalwarts, such as the golden eagles, the raven and the irrepressible hooded crows. Silence settles across the land. The few species that are left frequent a changed world. Soon only the buzzards and wood pigeons will hang on in the woods, and the coniferous forests will host flocks of chaffinches, tits, siskins and crossbills passing through. Waders from Russia, Scandinavia and the Arctic will flood to our shores and flotillas of ducks and geese will gather on the tidal mud – but I am getting ahead of myself. On a full moon the temperature plunges overnight, a careening splashdown to zero as the Earth’s heat soars to the Milky Way. By dawn Lucy’s dahlias have collapsed at the thought, the last nasturtiums have flopped like burst balloons and the stinging nettles are hanging their heads, like convicts awaiting execution – they know their number is up. Even if we are blessed with an Indian summer for a week or two in October, the natural world isn’t fooled for long. There is urgent business afoot. To ignore the signals and loiter is to court disaster. Suddenly everything has changed. * * * A dank drizzle settled over the Highlands. By dawn the river had risen from a whisper to an urgent murmur. Mists shrouded the dark flow and clung between the bankside alders well into the morning. We awoke to a damp, rusting-away world of yellow and umber. The shortening days seemed to be draining the paling chlorophyll with them. Trails of fieldfares and redwings chattered across the sky and descended like archangels onto rowan trees now bright and laden with scarlet fruit, hurrying, stripping them bare, moving on in undulating squadrons as though they had some pressing appointment elsewhere. Later the sun came sidling in. It is low now, its power vanquished, enfeebled by the year’s reeling. It will track a lower path every day until midwinter, 21/22 December, the winter solstice and the longest night, when, imperceptibly at first, it will begin to lift again. At our latitude, north of the 57th parallel, a laggard sun rises late in midwinter and barely lifts above our hilly horizon, sloping off as soon as it can, by about three in the afternoon. Cool and remote, it’s a token appearance, a mere gesture to remind us that spring and summer will, with luck, one day return. At eleven this morning it cut swathes of gilded light into the trees and across the green lawn, absorbing all the colours into one glorious October gleam charged with a cool and ruthless beauty. I stepped from shade into its glamour, then back again to see if I could detect any warmth. I could, but only just. That alone should be enough to tell the natural world to hurry along, to wrap up and get ready for what is to come. Yet it is the intensity of the light that dictates the radiance of the autumn leaf colour. Leaves absorb red and blue wavelengths from sunlight, reflecting the green light to us. Green is good. Green tells us the tree is alive and well. If something goes wrong, such as a drought, the leaves begin to yellow because the green chlorophyll is no longer being fed, causing it to break down. It can’t absorb the red light any longer, so it gets reflected outward to our eyes. It is this mixture of red and green light that creates the yellow. The loss of green is a biochemical phenomenon with high, show-stopping drama and profoundly poetic consequences. Autumn colour is the universal manifestation of the same process. Dictated by plant hormones, as the length of daylight recedes, the water and minerals, especially phosphate, that have fuelled photosynthesis all summer long, are cut off in deciduous plants at the stem of the leaf. The powerful green pigment in chloroplasts, chlorophyll – which, as every biology pupil knows, is the essential component for converting sunlight into sugars and is responsible for what John Cowper Powys described as ‘an enormous green tidal wave, composed of a substance more translucent than water, has flowed over the whole earth’ and what I call the ‘great green stain of summer’ – begins to fade because it can no longer replace itself. Without the supply of water and phosphate, chlorophyll burns itself up and disappears, allowing other pigments that are always there but drowned by the green wave, to begin to show through. These are principally carotenoids, bright yellows and oranges, and anthocyanins, the reds and purples, hence the drama and the rush for the poet’s pen. But their celebrity is brief: they, too, are doomed to the same fate as the chlorophyll, which is why this whole process is uncharitably dubbed ‘autumnal senescence’. As the nights grow steadily cooler, the anthocyanins are responsible for removing sugars from the leaves the tree
