Nature Studies by Michael McCarthy: Survival skills of the highest order

Alpine Dorset: that was a new one on me, in the heart of that most gently rolling of counties, but such the landscape seemed to be as we trudged on Christmas Day up the slopes of Maiden Castle, the colossal prehistoric hillfort on the outskirts of Dorchester. As far as the eye could see the countryside was white, apart from the woodlands which were black against the snow, while above, all was blue: a high-pressure system meant there was no cloud in the sky, and the sun poured down unhindered. Blinding white, luminous blue, searing sun: I've only seen that palette high in the Alps, on skiing holidays.

Our ambitions didn't run to skiing, but the sledging was terrific, long gentle runs with steepness available for the daring, through ideal snow, a good six inches of it (and the words actually came into my mind, deep and crisp and even). It was like rediscovering winter in England. But enjoyable as it was for the well-wrapped-up, I did wonder how it must be for an animal or a bird in that world, where brown and green have gone and freezing white is all. There was little life to be seen, apart from a distant flock of golden plovers, wheeling in clouds and wisps; when later, from the top, I spotted them in the binoculars settled in a snowy field half a mile away, they seemed as tiny as a dusting of black pepper on the white of a fried egg. You couldn't take an awful lot of the wholly white world, I thought, if you were a wild creature; and then once more I remembered the Alps.

I've had three goes at skiing: in my early twenties in the Pyrenees, in my early thirties in Austria, and then as a father, a more serious attempt in the French Alps with the children, before a torn knee cartilage grounded me.

In France we went to Les Arcs, where we had a good instructor called Jean-Jacques who taught us to come down the mountain while we helped him to fire up his English, for example with the use of the word "hairy", as in Wow! That was hairy! ("What is hairy?" said Jean-Jacques. It means, frightening, scary, fearful, we said. The next morning he greeted my daughter with the words: "Are you feeling hairy today, Flora?")

But if his English was occasionally idiosyncratic, Jean-Jacques' forte was that he was energetic, not to say adventurous, taking us all over the mountains; and on these long trips over the seemingly empty white Alpine desert, I began to see birds.

The first ones I saw below me, from the chairlift, in a blizzard about 7,000ft up. They were brown and chaffinch-sized, but the noticeable thing about them was the big white patches on their wings, which made them stunningly pretty in flight. At first I thought they were snow buntings, but I looked them up in the guide afterwards and they turned out to be something even more exotic: snow finches, birds of the high altitudes, which do not occur in Britain. A new bird for me.

The next species was hopping inconspicuously around the terrace of a café, a birders' LBJ, or little brown job; you might not give it a second glance, but as I looked at it closely, it dawned on me with delight that this was the mountain cousin of our dunnock, or hedge sparrow: the alpine accentor. This was another first for me and even higher, at about 8,000ft.

The third one was the most impressive, and also the highest of all. Jean-Jacques took us to the top of the local peak, the Aiguille Rouge, with glorious unimpeded views across to Mont Blanc; but my eye was also caught by a flock of black, medium-sized birds with yellow bills which were tumbling in the air around the cable car station. "They're jackdaws," Jean-Jacques said, dismissing them with the French word choucas, and indeed they were jackdaw-sized; but I knew, though once again I had never seen them before, that they were something much more out of the ordinary. They were alpine choughs, close relatives of our own choughs, those charismatic crows with scarlet legs and bills which have just returned to breed on the cliffs of the Cornish coast.

I could scarcely believe I was seeing them; we were 3,227 metres up, which is more than 10,500ft. How on earth did they survive up here? What could you find to feed on in the wholly white world? But later when I read up on them, I learnt that this was nothing; alpine choughs had been observed nesting in Asia at more than 21,000ft, and were probably the highest-nesting birds in the world.

All of them, the choughs, the alpine accentors and the snow finches, came back to me vividly as I stood on the top of Maiden Castle on Christmas Day, looking over snow-blanketed Dorset and thinking how hard it was for anything to survive out there. I realised I was mistaken; life can be a lot tougher than we think, especially life that has evolved to cope with extremes. So say hello to them for me, if you're off on a skiing holiday, the birds of the white world of the Alps; if you can take your eye off the piste now and then, you may find there's more to the mountains in winter than black runs and mulled wine.