Following a bird of flames and fable

What do I remember of Saskatoon, Saskatchewan, a destination dredged from times past? An early spring temperature of 30 below, oddly dry and tolerable. A vast Victorian hotel in which I seemed to be the only guest. A Hudson Bay Company store selling melancholy Inuit carvings of seals. And then - suddenly, in colour - my first waxwings, rustling acrobatically through the frosted wands of the city's municipal shrubs.

Everyone, it seems, remembers their first waxwings, and not just for the brilliant accents of scarlet and yellow in the feathers of wings and tail. "Softly rounded, crested; charming, unreal" offers one British field-guide, and indeed, in their wanderings, it is the unreal bit that scores. A pair of waxwings perched on garden posts across the road from Kruger's bar in Dun Chaoin on a snowy Dingle Peninsula must have seemed positively visionary.

That was on December 29th, an observation duly flashed by e-mail around Ireland's birdwatchers by Ballyferriter's Jill Crosher. There were answering flickers of sightings from Dublin and Antrim, and further reports of substantial Viking parties sifting down from Scotland to the Isle of Mull and Merseyside, even the Channel Islands. A memorable invasion of Ireland seemed distinctly on the cards - indeed, may already be here.

The waxwing is a fabulous bird - the "flames" on its wings, which caused Pliny to name it Incendiaria avis, were said to light up the night in the immense and ancient Hercynian forest of Germany. And for a long time the periodic winter irruptions of waxwings, apparently from nowhere, evoked superstitious awe as dire portents of wars and plagues (perhaps also, in 2001, a US recession?).

As late as 1851, the Dublin ornithologist John Watters wrote: "Its breeding haunts, to the present day, have been hidden in the greatest obscurity, as in no country have they ever been discovered". Its fuller common name, Bohemian waxwing, was no help, since the bird's breeding haunts were eventually tracked far from Czecho or Slovakia to remote, wet and mossy forests in Europe's northern conifer belt, from Norway to Siberia. The first nest was found in 1856.

In North America, Bombycilla garrulus (the modern name makes far more noise than a diffident trill of zhreee would seem to justify) keeps the Bohemian tag, partly to sort it from the similar cedar waxwing, and there it nests in forests from Alaska to Hudson Bay.

In most years, the European waxwings breed at quite low densities and are rarely seen outside the taiga woods. In summer, they feed exclusively on mosquitoes, darting after them like flycatchers, but the key to their irruptions is the rowan berry, their staple food in autumn and winter. Years of good berry crops will boost their population and then, at a peak of waxwing numbers, the exhausted trees have a poor crop that sends the birds streaming south-west for food, sometimes in flocks of thousands.

Ireland and Britain are at the final fringe of the waxwings' range, and by the time the birds are here the rowan crop may already have been stripped. Even the hawthorn berries have now disappeared, picked off by the great flocks of fieldfares and redwings that flew west ahead of the snow. Our resident thrushes sometimes defend their share: John Watters described how, near Dublin in January, 1851, mistle thrushes attacked and drove off a pair of waxwings who were filling their stomachs with haws.

Thus, the image of waxwings most common in irruption years in Ireland is of small parties of surprisingly tame birds in parks and suburban gardens, energetically stripping the berries from cotoneaster and other shrubs. In the winter of 1998-99, for example, Dublin's Tallaght was the favoured locality: about 50 waxwings arrived there in December and remained all winter, even singing from trees in mid-April.

Apples are a great attraction. In Tralee, Co Kerry, three winters ago, waxwings arrived to feed on ornamental crab-apples in Dunne's car-park. I have hung a string of small apples in the bare hawthorn hedge on the chance of catching the eye of a passing irruptor or two.

With enough logs cut for the stove and no cause to travel, I was able to welcome the Christmas snow and ice, not just for its magical etching of mountains and islands but as a proper state of winter, a brief interval of death and cleansing, more beneficial to our island ecosystem than interminable muggy rain and wind.

It is not just as gardener that I endorse the mortality of millions of aphids, the merciful, overdue withering of plants. Something deep in my genes demands that winter, at this latitude, be bloody cold for long enough to start the spring from scratch.

"A million birds may die" was a good green headline to keep the nut-feeders filled and the bird-tables heaped with Christmas crumbs. But does this do more than help to maintain a handful of seedeating species who don't mind being peered at through kitchen windows? It does nothing for wrens, for example, or goldcrests, both leading casualties of any severe winter, or for unconsidered species like kingfishers and snipe, who need ice-free streams and soft marshes.

Indeed, of the 18 species on the new red list of "birds of conservation concern" discussed in the new issue of Irish Birds, the annual journal of BirdWatch Ireland, not one is amenable to bird-table welfare: how do you ease the cold-weather lives of lapwings, barn owls, hen harriers?

But if helping to feed a marginal percentage of perhaps a dozen kinds of birds in winter gives us pleasure, gets us interested and sympathetic, and helps the membership funds of conservation NGOs, the arithmetic of rescue is irrelevant: this is a worthwhile and reflective bond with nature.

Irish Birds costs £9, from BirdWatch Ireland, Ruttledge House, 8 Longford Place, Monkstown, Co Dublin.

Birds in Central Ireland, the second mid-Shannon bird report edited by Stephen Heery, has a guide to birdwatching in the new Lough Boora Parklands. It costs £6, also from BirdWatch Ireland.