Watchers at the lake

A STRONG wind from the east meets the Atlantic head-on, shocking the waves into shades of sapphire-blue not seen at any other time. It lifts a mane of fine spray from the crest of each breaker and combs it backwards, out to sea. On the strand the little sanderling tracking the foam's edged seem more than usually unsure of whether they're coming or going.

It is a day for keeping your head down. At the lake behind the dunes all the mallard are ashore, pottering about on the bank or dozing with their beaks thrust back into the warm air under their feathers. The open water is left to the swans, dozens of white bums up-ended like traffic cones. I have my own head down, crouched in the little cashel that overlooks the lake, binoculars propped on the tumbled stones.

A swan can stretch its long neck below the surface for some 90 centimetres and stay like that for 30 seconds, swallowing its food without coming up to breathe. This can be a frustration to an impatient census-taker, sorting mute swans from whoopers, but mutes do have pointier bums than whoopers, as well as different-coloured bills. Finally, if I have got them all, there are 37 whoopers and 15 mutes - quite an assembly for one small lake so far on into the winter, certainly a few more than I can ever recall.

One reason could be found in the long, hot summer, which built up the growth of zostera, or eel-grass, on the lake's sandy bed: a food supply waiting to be harvested. The resident pair of mute swans reared five cygnets and tried to stake out a claim to half the water when the first of the whoopers flew in from Iceland. By November, with the invaders tip to 40, the adult mules were still arching their wings in warning whenever the whoopers swam over the line.

Even when apparently well-mingled, mutes have a different manner from whoopers. The native swans remain relaxed and self-possessed: their biggest group the family. Some of the whoopers have families, too, but their instincts are those of the corporate flock: wild senses, tuned to danger, quick to take the nod to fly.

How Ireland's three swan species share out our myriad stretches of water is one interest of the Irish Wetland Bird Survey, organised through the IWC and the Wildlife Service and now in its second winter.

Numbers of mute swans are probably at saturation level on the canals and rivers and park ponds around Dublin but they do seem to be fewer than they should be in winter on many suitable lakes in the midlands.

The question here is whether the swans are being poisoned by lead-pellets discarded by coarse anglers and peeked up by the birds with grit for their gizzards. (Since these weights were banned in Britain eight years ago, swans have increased on some rivers to the point of becoming a pest on farm grassland along the banks.)

We now have about 10,000 mute swans and 10,500 wintering whoopers. That's almost two-thirds of the Iceland whooper population and it shows a dramatic increase during recent decades. Before 1930, only Lough Swilly in Donegal was a regulars wintering-ground for the swans. Now, Loughs Swilly and Foyle are a staging post for a great flow of whoopers arriving in autumn and pressing on to Britain and every corner of Ireland.

They are continuing to spread into wetlands which were once the exclusive preserve of Ireland's third kind of swan, the Bewick's. This is a winter migrant from northern Russia, smaller and more goose-like than the whooper, and with a smaller wedge of lemon-yellow on its bill.

We have about 2,300 Bewick's swans, a figure remaining much the same while the other two species increase. Competition from the whoopers may be one reason, but another is the "free lunch" handed out to swans at the big wildfowl sanctuaries in England: the hungry migrants from Russia linger at Slimbridge and Martin Mere, instead of flying on to forage at the Wexford Slobs.

Hundreds of the whoopers now wintering here have bright-yellow collars or leg-banks engraved with a letter and a number in black. These were affixed on the swans' breeding-grounds in Iceland or at wildfowl reserves in Britain. Reports of winter sightings* are building up a somewhat unexpected picture of interchange between this country and Britain. They suggest, t9o, that while some whoopers come year after year to the same Irish waters many others are less faithful, or move about from one site to another.

Finishing an unproductive scan of legs and necks (and really one needs a telescope at any range), I became aware of a sudden, electric presence in the sky: there were other watchers at the lake.

Even in a stiff wind, a peregrine falcon can hang, steady and level tail fanned for lift, sharp wings winnowing the airflow. And here was not just one, but a pair of peregrines, holding their stations at separate levels, the male above, the larger female 20 feet below. Watching them hover, the mountainside blue and hazy behind them, was to store up a classic image.

The swans, of course, were in different. The heron in the stream at the end of the lake at least pretended to be. Even the ducks, which should have worried most, seemed to do no more than lift an eyelid. Nothing flew. The falcons moved from here to there and there to here, without finding anything to tempt them. The wind was cold. The tide would soon flow tip the channel, cutting me off.

One of these days I'll see a peregrine stoop - but not, as it were, when I'm watching.