Midsummer's drought diverges from past deluges

ANOTHER LIFE:LIKE GHOSTS OF an old underpainting, tawny shades of drought have been creeping across the hillside, sketching in the ribs of rock and hummocks of glacial gravel so shallowly skimmed with grass. By Midsummer's Day we were longing for the showers that even the winsome weatherpersons on TV no longer dared to call a risk.

For half a year we have watched the rain passing us by on the weather maps, leaving this corner of Mayo largely high and dry. Until the first tentative skifts of drizzle edged in from the Atlantic this week – a mere thickening of the atmosphere – our “moisture deficit” was close to Belmullet’s 37mm.

This would fill almost four times the calibrated measuring glass, a long crystal condom, that I take to the rain gauge in the lawn each morning, noting the amounts for Met Éireann’s benefit. Usually, 10mm is a good wet day. In the six months to Midsummer’s Day the total was 312.2mm, compared with last year’s 539.1mm and the 707.2mm of 2008 (which was, indeed, a bit much).

We still take our water by gravity feed from the hill stream. A long pipe finally wriggles in behind an immovable boulder to rest in a crevice of the shallow pool above. The stream itself has dwindled to a single shadowy thread, ducking under rocks for metres on end and barely uttering a tinkle on its way from the bog to the sea.

The pool, which you could almost cover with your doormat, drains out through a gap between the grassy bank and the boulder, a gap choked with cobbles of various size. Improving this “dam”, I note from the column’s archive, has been an enterprise of droughts reaching back to the 1980s. This year’s technological advance was to tie each little sod of turf (carved from the bank with a penknife) into a plastic freezer bag before working it into any likely-looking hole between the rocks. Plasticine might have done a better job.

Meanwhile, we balance the trickle into the pool with our domestic needs far below and take the washing-up water out to wet the potatoes – a microcosmic reminder that, as the climate changes, much of Ireland’s commercial potato-growing may have to come to an end.

The words “moisture deficit” began to creep into the weather bulletins this week, as it became clear that a few showers from the Atlantic were unlikely to offer what was needed. Seeking definition, I consulted Met Éireann’s website. Soil moisture deficit is the term for the amount of rain needed to bring the soil back to its “field capacity” (or, as the website adds helpfully, “the maximum water a pot plant can be watered and not leak water’). In the model developed for Ireland, the 37mm that Belmullet lacks is the deficit for well-drained soil.

Aside from our domestic anxieties over water (we may, at last, have to build a tank or drill a well), the downside of future “glorious” summers has already been spelled out in Ireland’s climate-change scenarios.

Friends back from climbing Mweelrea Mountain were ecstatic at the ease of their march across slopes of crunchy, dried-up bog. On the higher slopes, runs of hot dry days shrink the peat and open cracks to the bedrock.

The very extremes of climate promised for parts of Ireland – both drought and deluge, in place of moderately cool summers and soft days, threaten large areas of blanket bog on the western hills. The report on multiple landslides in north Mayo in September 2003 – more than 40 of them, in spectacular falls – described the “cracked zones within the peat” that let an intense localised cloudburst sweep the steep bog from its moorings.

Invertebrate wildlife, meanwhile, wrestles with a parched terrain. We may have been spared a few million midges, whose eggs and larvae have dried out on the bogs. Many flies need the moister forms of rot and decay on which to feed, and ants and other insects need water to swell their eggs. Dormancy and diapause are insect ways of waiting out a drought.

In the sand dunes, marram grass has rolled its leaves into tubes to reduce its water loss through transpiration. Little snails have climbed up the stems, where it is cooler, and closed their doors in the temporary opting-out known as summer aestivation. Earthworms have retired to the bottom of their tunnels and slugs to their coolest, darkest corners underneath things.

Where are the migrant butterflies? Last summer saw a spectacular invasion of painted lady butterflies from Africa. This season’s merest scatter of single painted ladies and red admirals speaks of strange weather in southern Europe. One looks at its weeks of downpours for an answer – weather, no doubt, that was really meant for us.

Eye on nature

While driving with my dad from Kildare to Clare I spotted what I thought was spider’s web on some bushes. They were covered with the web and appeared to be dead, and larvae like very small yellow- and-black caterpillars were hatching.

Conor Slattery, Ennis, Co Clare

I have observed webs like a deposition on hedgerows in Cork and Clare. In some instances the foliage has been stripped.

Vincent Delaney, Six-Mile-Bridge, Co Clare

The caterpillars of several of the small ermine species of moth spin webs on bushes and trees and, inside their shelter, feed on the leaves, often damaging them severely. The moths are usually whitish.

A swallows’ nest in our porch has been used on winter nights by wrens for years. A few weeks ago one wren went further: he built up the swallows’ nest to roof level to his own design and purpose. A case of wrenovation?

Lesley Wishart, Portballintrae, Co Antrim

I saw a mouse-like creature at the peanut feeder. It was not very small for a mouse with a golden coat. Was it a dormouse or a harvest mouse?

Fons Jasper, Portlaw, Co Waterford

It was the wood mouse (Apodemus sylvaticus). Dormouse and harvest mouse are not found in Ireland.

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