Why must lights be so shiny?

AMONG last year's Christmas presents was a square lantern with a candle in it a brand new model, in galvanised zinc, of the sort that once made tinsmithing an honourable craft and has now, it seems, found fashion again as an accessory for dinner parties in houses with dark garden paths (even, conceivably, as a prop for carol-singers).

It was a gift from city friends who remembered, perhaps, the sudden, stunning blackness of a country house when a gale gust brings down an ESB pole somewhere on the bog. There are candle-stumps clustered on top of the kitchen dresser and even the odd Wee-Willie-Winkie pottery candleholder scattered around the house - but a lantern at once earns its permanent, reliable place in the porch.

It gives a kindly glow. Sometimes, indeed, we hang it from one of our little oaks when friends are coming, the living flame so much more of a welcome than the bare yard light.

Something dreadful has happened to the new yard-tights of many small farms and lone country houses in the west. They have suddenly taken on a searing intensity, reminiscent of urban factories with guard-dogs and razor-wire. They are meant not to welcome, but to frighten off the bogeymen, the hit-and-run outlaws. So a couple of dozen petty thugs have been allowed to get between us and the stars.

The late Tony Whilde, completing his Natural History Of Connemara a few years ago, wrote that, while a lighted window can be warm and welcoming "blinding porch lights and glaring street lamps are an insult to the night sky - which is as much a part of Connemara's heritage as the rocks, water, wind and wildlife." I thought of him recently when, out for a night walk, I found another new arc-light, this one dazzling a river glen where once there had been soft darkness and the mystery of water-music. I turned back, dispirited.

But for most people living at the edge of Ireland, any new light in the landscape is an improvement, a token of human togetherness. Our own house, when we came to it, had stood empty for 20 years, and our first lights, shining out from the hillside, brought neighbours to their windows to enjoy the moment.

Looking out across the bay to Connemara, would I really want to lose the twinkling chain of street lights, first installed years ago for the holiday cottages at Tully Cross and now stretching along the coast to Renvyle? At this distance, their effect is charming against the black mountain, like the lights strung on Brighton's pier when I was young. But how I would hate to have them shining outside our gate!

Some recent callers live on a country road near Celbridge, in Dublin's commuter belt. When a computer factory arrived in the field next door, they tried to think only of the jobs and the young lives given encouragement. Even all the cars, shift by shift, were something to get used to. What has really hurt is the new row of street lights opposite the factory: the high, impersonal, urban glare banishes the shadows - and the stars - and quenches all feeling of a countryside at rest.

There are degrees of light, like degrees of noise; some we love and some we find intolerable. Our candle lantern, swinging from a tree, sets people smiling with pleasure and surprise. On another scale, the reproduction Victorian street lamps installed in Louisburgh and Westport have a rightness and mellowness that instantly disarms.

The "bloom" of artificial light that hangs above big cities is part of a pollution of the night sky which is seriously irksome to astronomers. It would not be entirely surprising if it also interfered in some way with patterns of night migration and the weather-movements of birds. If migrants are attracted - often fatally - to the circling beams of lighthouses, why do they not dash themselves against the radiant arrays of motorway lighting

The navigation systems of migrating birds are a complex mixture of the visual and the magnetic. While they seem to prefer cloudless nights with stars and a moon, they seem equally well-oriented when flying beneath a cloud cover. They certainly aligns their compass by using the Earth's magnetic field, but also need, to some extent, to see where they are going.

What does confuse them is mist or fog that obscures their horizon. In these conditions, an isolated pool of strong but scattered light can draw birds by the hundred; perhaps they mistake it for the moon.

For one or two species, the light of big cities is just part of the warmth that brings them in to roost, and the plane trees in the centre of Dublin have exercised a notable attraction. Europe's earliest recorded urban roost of starlings was in these trees in the 1840s. And later, when the starlings had moved on to the ledges of big buildings, it was the turn of hundreds of pied wagtails to spend the night in the branches of trees in the centre of O'Connell Street, indifferent to the clanging of trams.

It's now almost 70 years since this phenomenon began, bringing crowds to see trees "covered with silver leaves" as the wagtails' white bellies shone in the light of the streetlamps. In some winters, their numbers have reached more than 3,500.

I last watched their assembly in the early 1980s, standing in the flow of Christmas shoppers, about level with the Parnell Monument. At 20 minutes after sunset - about half-past-four - the wagtails began dropping down from every point of the deepening blue sky, like bees returning to a hive. They alighted in the twigs above the Christmas fairy lights and moved restlessly among the dark, round bobbles of the plane tree fruits, twittering in a vigorous evensong. Within an hour they were still, and the city roared on around them.