Another Life/Michael Viney: Once, at the lake behind the dunes, I found three flamingoes trailing their bills through the sandy shallows. The sight was all the more surreal since the deep coral pink of their arching necks marked them as natives of Chile, rather than France's Camargue. They were fugitives, not wanderers, but no zoo or landed pop star ever declared their loss.
Last autumn it was spoonbills, just up the coast at Westport - 10 of them together, the largest flock ever recorded in Ireland. Rings on some of their long legs marked them as wanderers from the Netherlands. Their snowy gleam against the dun mud of the estuary made me eager for a share of Ireland's other desirable aliens, the little egrets. Here am I, above a shore liberally ribboned, marshed and pooled with vacant water, while egrets are gliding above Dublin like exotic paper aeroplanes or hunched in suburban conifers as if brought home from the nearest garden centre.
Cóilín MacLochlainn, who edits Wings for BirdWatch Ireland, has been keeping tabs on sightings of the city's wintering egrets, and would welcome further records at environs@iol.ie. He currently allots at least one bird to each of the following suburbs: Deansgrange/Cabinteely, Belfield, Loughlinstown, Dundrum, Harold's Cross, Templeogue, Drumcondra and Blanchardstown. All they seem to need is a stretch of fresh water, some open and peaceful green space, and a few tall trees for roosting in.
This, of course, leaves aside the sightings in the egrets' regular coastal haunts at the North Bull and Booterstown Marsh, and estuaries and marshes to the north and south of the city. The rapid growth in their east coast population, MacLochlainn suggests, is pushing the wintering egrets inland. And behind their suburban explorations lies the sudden, thrusting expansion that has colonised southern Britain and Ireland and added this elegant little heron to the roster of native birds.
Egretta garzetta belongs to a great tribe of herons spread across the world - 60 different species, and lots of races within species.
Like America's snowy egret, which has even more impressive head-plumes in the breeding season, it was quite wiped out in some places by the demands of the high-society hat trade, a market that ceased only with the first World War. America's first Audubon societies had their origins in concern about the egrets.
But the egret family has also undergone some extraordinary expansions. The cattle egret, for example, a southern Old World species, arrived mysteriously in British Guiana in South America in about 1915, perhaps blown across from the bulge of Africa.
Today, they peck up insects stirred by cattle as far north as Newfoundland, with nesting common right down the Atlantic coast.
The spread of the little egret's breeding range north and west in Europe was a spectacular trend of the 1990s. The bird began visiting Ireland half a century ago, a startling white stranger on muddy creeks and estuaries, particularly in Cork. In the 1970s the bird began coming in numbers and staying for longer, and a comparable build-up on the south and east coasts of Britain brought the first breeding record in Dorset in 1996. A year later, the egrets built a dozen twiggy nests alongside those of grey herons in a long row of beech trees in the Blackwater Valley north of Youghal, Co Cork, and hatched out 29 chicks.
By 2001, there were 57 nests in three separate colonies near the south coast, with some only two miles from the centre of Cork city. There was breeding near the coastal marshes on north Wicklow in 2003, and the search will be on this spring for likely new colonies in Co Dublin.
The ornamental plumes for which the egrets are known are quite variable and juvenile birds may have none at all. But as courtship approaches, the adults of both sexes grow two or three long, slender plumes from the nape and more from the throat, and their yellow feet turn red.
The plumes are not just for attraction, but stick up like the ruff of an angry dog in "hostile social display". Now, too, is when the egrets get noisy, making growling and gulping sounds when excited or defending a feeding site. They eat little fish, crustaceans and molluscs, but also insects, worms and frogs.
On the west coast, the northward spread of Egretta garzetta seems to have got stuck at the inner reaches of Galway Bay, but it will be surprising if climate change does not ultimately tempt the birds to the lusher corners of Clew Bay and beyond.