Nature Studies by Michael McCarthy: Welcome signs that winter's on its way

If we greet the bringers of spring with elation, should we greet the bringers of autumn with gloom? Logically, I suppose we should. But we don't seem to and I wonder why this is. Anyone close to the countryside knows the delight of hearing the first chiffchaff singing in March, having returned from the Mediterranean, and then the first willow warbler a little later; and even more, the pleasure of seeing the first swallow in April, just back from South Africa. The intensity of our welcome of these migrant birds is in large measure a seasonal one: they are signalling the great change in the calendar, the shift from warm to cold, from dark to light, and even more, the move in the natural world from death to rebirth. No wonder the first sound and sight of them make many hearts skip a beat.

Yet there is a reverse migration, the mirror-image of the spring one, which people are much less familiar with, and which is in full swing right now. This is the journey here of birds from northern countries which are colder than ours, birds which find wintry Britain not a bad place to be, all things considered. It is led by two thrushes which breed in Scandinavia, redwings and fieldfares, and as you read this they are pouring into Britain in their thousands, having flown the 500 miles across the North Sea, often in the dark.

You can see it happening, or at least you can see a visualisation of it happening, if you log on to the BirdTrack website of the British Trust for Ornithology, where the observations of a network of several thousand human observers are put online every week and represented on a map of Britain as red dots: you can watch an animated weekly progression of dots covering the country as the migrants flood in. With redwings, for example, there was nothing at all up to the weekend of 11 September, but by the weekend of 18 September there were four dots on the map, one in the Thames Valley, one in north Norfolk and two in the South Pennines – scattered early arrivals. This had moved up to eight dots by the weekend of 25 September, and by last weekend, 2 October, there were more than 75; by this weekend, the figure will have exploded and the redwing map of Britain will look like a case of chickenpox.

To see the birds themselves, charming smaller versions of a song thrush with orange flanks and a yellow eye-stripe, you have to get out into the countryside, as they do come into gardens, but not until they've had all the berries of the hedges and the really icy weather sets in. In towns, experienced birders can hear them as the flocks fly overhead at night, since they utter a characteristic seeip! call: a birding friend of mine told me this week he heard an unmistakeable redwing in the dark overhead between parking his car outside the house and reaching the front door.

But he was pleased. And the point I'm making is, doesn't anyone ever groan? Doesn't anyone ever go: "Oh gawd, there's the first redwing, winter will be here any minute, sodden grey mornings, endless dark evenings, doses of flu, huge electricity bills, old people slipping on the ice and dying of hypothermia?"

They don't seem to. Any more than they do when they see or hear the first fieldfares: grey-headed, slightly larger thrushes which will be here soon, too, or the first wild swans, the whoopers from Iceland and the Bewick's swans from Siberia, or the first skeins of wild geese, the white fronts, the pink feet, the brents and the barnacles from all round the Arctic which are heading here now for their winter break.

Even the birds whose arrival from Scandinavia signals the true cold, like the woodcocks and the great grey shrikes – about 150 of the latter end up with us each year, terrific things, hunting from solitary trees on lowland heaths – seem to generate pleasure in the observer rather than foreboding; though their arrival is the clearest of signs that the year is dying and the cold, wet, dead times are upon us.

Why? Why do we rejoice in the signs of spring and summer, without despairing at the signs of autumn and winter, even taking pleasure in them, as with the autumn foliage?

Maybe it's because the Earth's annual cycle is too embedded in our genes to protest at it deeply, even though we may curse it now on the surface. Doing away with winter is a new idea: central heating is about two human generations old. But having to live with it goes back, what, 20,000 generations? More?

Maybe also there is something in the nature of the natural world with an appeal to us which is not season-dependent. This means that the variation of the seasons carries its own fascination and excitement, even for the ones we celebrate with less ardour than the spring. That certainly works for me: I love the mist and tang of autumn; I look forward to snow. And maybe, ultimately, it tells us something about the essence of the natural world: that all of it is beautiful, not just the bits which happen to suit us best.

Read it in the stars

There are even grander signs of winter coming than the skeins of wild geese. A week ago I woke in the middle of the night and happened to glance out of the landing window: there, half-risen, was Orion, the greatest of all the constellations. Orion disappears (for British observers) in the summer, but now it is returning and it will be above our garden, blazing in the South-east, on freezing January evenings.

m.mccarthy@independent.co.uk