Singing in a burst of seraphic melody

Another Life: For a heartfelt response to nature, there was nothing to beat a Victorian in full rhapsodic flow.

A friend wrote from Achill to John Watters, a Dublin ornithologist, about the song of the linnet: "It has occasionally moved me to tears. Many times I have been sitting by the heath-side on the hills of Achill when the entire bosom of the Atlantic appeared one molten sheet of silver, prismed with the rainbow reflections of the setting sun; and suddenly heard, breaking the solemn silence of the place, fifty or a hundred linnets. . . singing in one united chorus a burst of seraphic melody. . ."

Now that the summer people have gone, and a delicious quietude envelops the hillside, I find myself listening for something like that. September is when finches start flocking and linnets, in particular, dance about the fields and dunes in little packs. They skip between drifts of thistledown and sometimes pause for a communal twitter on a thorn bush or fence wire: a bit wistfully autumnal, maybe, but nothing to weep over.

In spring, on the other hand, the cock linnet advertises himself with lively flutings, twangings and tremolos that once made it a favourite cage-bird of urban artisans. John Watters, writing in the 1850s, described "indefatigable shoemakers and tailors" among bird-catchers wending their way home in Dublin on Sunday mornings, carrying linnets in cages.

On a visit to Dublin in 1960, I was taken to the Bird Market, still housed on Sunday mornings in an alleyway in the Liberties - a melancholy cultural experience, even assuming that the birds were "captive-bred" as advertised. I wrote a poem, used in this newspaper, describing the market as "a cell confined by overpeering sculleries and walls" - preferable, perhaps, to giving the birds a view of open hills. Tennyson, too, had been moved by "The captive void of noble rage/ The linnet born within the cage/ That never knew the summer woods".

At that time, I scarcely knew one finch from another: how many people, today, outside of birdwatchers with field guides, have any idea of what a linnet looks like? (Answer: a small, streaky brown bird with a greyish head and, on the cock in summer, a pink brow and breast [ see drawing].) And if the linnet has faded from our consciousness in all but name, what chance is there for the twite? The what? The name is, perhaps, unfortunate. When Carduelis flavirostris was known as the mountain linnet, it had a place in public sentiment: as the twite, it's hard to take seriously. But "TWEit" (so rendered) is its almost continuous contact call in flight - a "hoarse, nasal, loud and rather twangy rasping sound ascending in pitch" says my most magisterial bird book - and, being audible 400 metres away, seems to have stuck as the name (the Irish, gleoiseach sléibhe, is "mountain chatterer", which is fair enough).

The twite was always the linnet of Ireland's wilder places, nesting on heathery mountain or grassy clifftops. A century ago, it bred even on the Blaskets and Inishturk. But, exclusively a seed-eater, it relied in autumn and winter on weed seeds at arable patches in a coastal countryside of mixed farming.

The disappearance of crops has already cost us the corn bunting and brought a steady decline to the linnet, Carduelis cannabina. But the twite's dire crisis has overtaken it almost unnoticed. Much of its nesting habitat has been overgrazed and impoverished, and as the archetypal "little brown bird", it is so easily overlooked in mixed flocks of finches on coastal fields and estuaries. Since the early 1970s, it has dwindled to an astonishingly low current estimate of 50-100 breeding pairs.

This figure comes from a preliminary study, funded by the National Parks and Wildlife Service, of the twite's remaining strongholds in north Co Mayo and west Co Donegal. Derek McLoughlin, of Newport, Co Mayo, working through the Sligo Institute of Technology, will now go on to a full ecological study of the twite - the first in Ireland - for his Ph D. Using colour-ringing, he will monitor the birds' movements from nesting sites to feeding-grounds and check exactly what seeds they eat - information that could help shape land management to save the species in Ireland.

I've never wittingly seen the bird, but will keep an eye out for longer linnets with yellow bills in the fields along the shore. I like the guidance in Rob Hume's 1990 pocket fieldguide, Birds by Character: "Subtle, streaky; small bill and head, long wings and tail. Short legs. Ground- loving, tight-knit, bounding flocks wheel up, then pour down to disappear again in vegetation." And all the time, of course, calling out their name: "TWEit . . . TWEit . . . TWEit."

• Derek McLoughlin is at The Coach House, Melcomb, Newport, Co Mayo; e-mail:  derekmcloughlin@eircom.net