How rare is rare?

Clochar na gCon (Foxrock as Bearla) is a breezy undulation of bog, well up the hill from the bungalows and buzzing traffic of the coastal ribbon between Galway and Inverin near Spiddal. Like so much of Connemara, bits of it have been overgrazed, hacked about and dumped on, but it is still enough of an intact, wet wilderness to warrant and reward protection. What is thrillingly clear from an intensive study of the bog this summer is how much of its wildlife remains undisturbed. As a very small stakeholder in its future, I can be proud.

Just which of the 5,000 acres of Clochar na gCon bog includes my acre I can't be sure, since the "symbolic" share certificate I have around somewhere doesn't actually give a Global Positioning Reference. But my moiety for land purchase helped the Irish Peatland Conservation Council to go into a conservation partnership with Duchas and the local community, so my little plot - in my own mind - can be anywhere I like.

It could include, for example, the lake island where the pair of merlin nested this year, foraging out after pipits and dragonflies: if we still have a dozen pairs of this tiny falcon left in Connemara, we're doing well. Or it could hold some of the wetter bog, where the seven pairs of golden plover were nesting, spaced out among the mossy hummocks as if by tape measure (400 metres apart each way).

In winter, Ireland is visited by great flocks of golden plover from Iceland, but our native birds have been dwindling fast, their nesting habitat stolen for forestry. A decade ago, some 40 pairs were found in south Connemara, mostly on the bogs north of Roundstone. Now they can be sure of another refuge, another place to wear the dazzling breeding plumage that so few of us ever get to see.

The loss of bog and its special plants reduces the diversity of insects, so the sighting of "plentiful" numbers of the large heath butterfly at Clochar na gCon was reassuring - even a big surprise, since none had been recorded in west Galway in 30 years. Such strictly local abundances are all the more mysterious when the food plants of a species are still so widespread: the large heath's caterpillar feeds on cottongrass and white-beaked sedge, both common bog plants.

But, for rarity, I'm happy to furnish my plot with a couple of bugs found by the IPCC and its Dutch researchers - insects so scarce they lack any common name.

Saldo morio, the size of a lentil, wanders the mud at the edge of bog pools, out to prey on creatures even smaller; it had not been recorded in Ireland in more than a century.

Psallus confusus is no bigger, but much more important. It is new to Ireland, but that still occurs quite often with small, overlookable insects in very big families. The real excitement is finding it in a fragment of ancient oak woodland on the bog: part of an ecosystem almost vanished from Ireland.

In all, five weeks of the survey found 192 species of birds, animals and plants, which gives some idea of the biodiversity inherent in our peatlands. The IPCC (119 Capel Street, Dublin 1) is trying to build up an emergency fund with which to buy more as the chance arises: even a quarter-acre (£30) gets a certificate for hanging in the loo.

How rare is rare? Degrees of scarcity are one concern of the new "Checklist of the Birds of Ireland" prepared by the Irish Rare Birds Committee and published by BirdWatch Ireland*. The list of our recorded birds has been transformed over the past few decades and now, at 424 species, confirms Ireland as one of the most flownpast and just-dropped-in-at places in western Europe.

A lot of the new names have been added simply through the greater intensity of watching. Co Cork is clearly the place to rush to for exotic warblers and thrushes and wind-blown vagrants (an American coot!), as well as the more regular bee-eaters and hoopoes from Europe.

Cape Clear Island, with its ornithological observatory, has added dozens of new species to the Irish list. "One, Cape Clear" occurs regularly in the checklist for such oddly-sorted vagrants as the yellow-bellied sapsucker (an American woodpecker), the grey catbird (like a mockingbird, and calls mee-ow) and the white-throated needletail (an Asian swift).

The other fruitful group of rarities are among the spectacular processions of migrant seabirds watched from Cape Clear and other vantage points in the south and west. The bird on the cover of the new checklist is the soft-plumaged petrel, Pterodroma mollis, an ocean species of such extreme rarity and uncertain status it doesn't actually get into the booklet.

It did, however, figure in the sightings reported the other morning by watchers on Loop Head. A soft-plumaged petrel was "loafing about with the Manxies [shearwaters] before moving off west . . . only to return again and give great views at 9.20 a.m."

This is the sort of intelligence one gets by signing up to the Irish Birds Network now operating on email: ibn-l@listserv.hea.ie. Along with the twitchers' thrills comes a fascinating miscellany of information and discussion, not least on the wisdom of saying too much on the exact whereabouts of rarities.

As one well-respected ornithologist put it lately: "When local people in a touristy area, but well outside the usual birding zones, hear that someone has found a rare bird, their first instinct is to put it on the local radio or papers in the hope that it will increase business over the weekend. Needless to say, they do a fair bit of poking around the bushes, usually to no effect, but not always."

For soft-plumaged petrels, on the other hand, they could put up a telescope on the cliffs and charge 50p a look. No guarantees, of course. . .

Price £5, including p & p, from BirdWatch Ireland, Ruttledge House, 8, Longford Place, Monkstown, Co Dublin