Why ecologists always fall for this wild wedge of coast

ANOTHER LIFE:DOOAGHTRY IS THE townland that separates us from the sea, a wild wedge of coast almost at the southerly toe of Co Mayo, where it dips into Killary Harbour, and as far from any town as you could wish. A single house and some dotted lines on the six-inch map keep its topographical identity alive. "Utterly windswept," noted Robert Lloyd Praeger in 1934, and "would well repay further study". A succession of field scientists would agree, as they parse this chaotic corner of landscape into ever finer distinctions of habitat and species. Like the poet Michael Longley, whose great inspiration it has been, they start out impressed by its huge horizons of mountain and sea but end up on their hands and knees (with a pocket lens), "taking it all in".

Thus, after surveys of plant life nibbled to the roots by sheep, of rare wetland snails no bigger than a match head, and rare liverworts whose beauty is also best shown by a magnifying glass, it comes as no surprise to be offered an appraisal of Dooaghtry’s mites – lumbering, armoured dinosaurs as the microscope makes them seem.

Beneath its boggy heights and framed by sandy lagoons where the whooper swans are calling, Dooaghtry’s big attraction to ecologists is the machair, with its great, flat lawn of sandy grassland behind the dunes.

Machair is a highly special landform confined to the galeswept western coasts of Ireland and Scotland and rated a priority habitat in Europe’s Natura conservation network.

Whether the “plain” that marks most of them was levelled from dunes by the wind or created by the filling of lagoons by wind-blown shell sand is still under question, but of 59 stretches of machair between Donegal and Galway, Dooaghtry is probably the best example. Heavily overgrazed by sheep in its time, it has escaped invasion by football pitches, caravan parks or airstrips, and only occasional boy bikers leave their tyre marks on the dunes.

Given the machairs’ unusual character and records of rare species, it was fair to wonder if some of their minutest micro-arthropods – the mites, or Acari – would be special to the ecosystem. Julio Arroyo, studying with Prof Thomas Bolger at University College Dublin, picked 10 sites, including Dooaghtry, and sifted out the mites (with a yoke called the Macfadyen high gradient extractor, since you ask) along a line from the newest foredunes on the beach and across the broad ridge of the dunes to the grassy plain behind them.

Of 111 kinds of mite in “rich and diverse” communities, two or three were new to Irish records – enough, anyway, to urge careful management of the machair in the Journal of Coastal Conservation. The most widespread mite is the virtually disc-shaped and salt-loving Scutovertex arenocolus, common among the roots of dune vegetation, where its rather slender legs are built for scrambling between grains of sand.

To go looking for what Scutovertex is good for is to enter an invertebrate realm of enormous diversity of form and function. Related to spiders, and with tropical scorpions somewhere in the family, they can range from the virtually invisible to the beautiful bright vermilion velvet mite, a few millimetres across, that I turn up from the soil when I am digging in spring.

Unike spiders or scorpions, which are entirely predatory, most mites in the soil or forest litter are slow-moving grazers on dead vegetation, algae, fungi, spores and bacteria. It’s just unfortunate that mites in houses also graze on dead flakes of human skin and that their droppings, in house dust, can prompt an allergenic asthma in people. Perhaps we could balance this with the good they do in grazing off the fungal powdery mildews that are considered such a nemesis to vineyards.

Scutovertex mites belong to the grazing group known as oribatids, or moss mites, sometimes credited with helping to “pollinate” mosses as they creep between them. Many Scutovertex species live in extreme environments, including the mosses and lichens of roofs and mountain rocks, and they can sometimes play a part in scientific findings with huge implications, biogeographically speaking.

There are moss mites, for example, living among lichens on the peaty summit of Mount Leinster, in Co Carlow. They have been found to mirror the montane species list across the Irish Sea, in Britain, and to show the same mix of arctic-alpine, European-alpine and lowland elements. Did they survive the last glacial periods of the Ice Age on the mountain top or arrive in a southerly land bridge across the Irish Sea – always supposing that it survived long enough for the tiny mites to creep across it?

“Like the poet Michael Longley, whose great inspiration Dooaghtry has been, field scientists start out impressed by its huge horizons of mountain and sea but end up on their hands and knees, taking it all in

Eye on nature

Why are there no maggots in the late, plump blackberries this year? Years ago you would be careful to check each one, but not now. The same is true of garden peas. The pea moth is probably reduced by insecticides in the fields around.

Marion Rowe, New Ross, Co, Wexford

The extreme cold earlier this year seems to have killed off the larvae and pupae of several insects. Most of the maggots in blackberries are the larvae of the raspberry beetle, which attacks raspberry, blackberry and loganberry fruits

With an ornithological observer friend I saw three gadwall, a drake and two ducks on Pollardstown Fen.

John Colleran, Pollardstown, Co Kildare

Gadwall are a scarce breeding species here, in Lough Neagh, on some lakes and turloughs in the west, and on the Wexford Slobs. Some also arrive for the winter from Iceland, Britain and Europe to lakes and marshes. This is a first report for Pollardstown Fen.

I spotted a squirrel in evergreen oaks with a grey tail, tan body and head colourings almost like a red squirrel. Is it a cross between a red and a grey squirrel?

Seán Owens, Balgriffin, Dublin 17

It was a grey squirrel.

Michael Viney welcomes observations at Thallabawn, Carrowniskey PO, Westport, Co Mayo, or viney@anu.ie. Please include a postal address