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3

Mountains and Uplands

Nothing more sharply exemplifies relativity than a mountain. A 100 metre-high hill in a flat landscape assumes mountainous proportions, but a normal arctic-alpine plant, casting a cold eye for a frosty north-facing cliff, would pass it by. Compared with their cousins in Wales, Northern England and Scotland, Irish mountains are not only generally lower but also cover a smaller proportion of the landscape and, as a consequence, offer fewer opportunities for a rich mountain, alpine or arctic-alpine flora and fauna.

Raven & Walters¹ define a mountain as land over 2,000 ft or 610 m – in practice any height above 600 m is generally accepted as mountain land – which puts only about 0.3% or some 240 km² of Ireland in the ‘mountain’ category with approximately 190 peaks penetrating the 600 m limit. ‘Upland’ is a more difficult issue and is taken to include all land between 300 and 600 m and as such would embrace some 4,100 km² of Ireland. Together, mountains and uplands occupy 5% of the country’s surface. Most elevations are located in the coastal counties with the notable exception of the Galty Mountains rising up from the south Tipperary lowlands to reach 919 m.

The great Irish botanist Nathaniel Colgan was the first person to point out that of the 67 species comprising the so-called Watsonian ‘highland’ group of plants found in Britain (named after the British botanist H.C.Watson), only 42 occurred in Ireland.² However, as Praeger has said, Watson’s definition of highland plants – ‘species chiefly seen about mountains’ – does not fit well in Ireland, where many of these plants are found in more places than just the mountains. Sixteen of them occur as far down as sea level.³ In the 1950s Raven & Walters provided a much more rigorous list of 150 ‘mountain’ species recorded in Britain and Ireland.¹ The vast majority of these fall into the ‘arctic-alpine’ category, i.e. plants that occur both in the Arctic and on some or all of the main European mountain ranges. If one ignores the taxonomically complicated and controversial dandelion-like hawkweeds (Hieraciums) and the real dandelions (Taraxacums), only 58 species or 39% of the Raven & Walters list are found in Ireland.

Despite the impoverished representation of the ‘highland’ and ‘mountain’ plants in Ireland, Colgan made some interesting discoveries in the Mayo and Galway Highlands. ‘It may sound like a paradox to say that the botanical survey of an Irish mountain region derives a peculiar zest from the very poverty of our flora in alpine species. Yet the assertion may be made with perfect truthfulness. That the rapture of discovery varies directly with the rarity of the object sought for, that the value of the thing attained is measured by the labour of attainment – these are time-honoured truisms in every system of proverbial philosophy; and their essential truth is daily borne in upon the mind of the botanist who devotes himself to the exploration of any of the mountain groups in Ireland.’

The natural history interest of Irish mountains and uplands derives primarily from their extreme ecological conditions and their possible role as refugia for flora and fauna during the Ice Age. Some of the present day plants and insects may be relict species, survivors of these earlier days. The astringency brought about by poor soil conditions, few nutrients, high rainfall, searing winds, low temperatures, cold and short summers, frost and intense sunlight underpins the existence of a remarkable assemblage of mountain lichens, mosses, ferns, flowering plants, invertebrates and vertebrates that are at home in and, in many cases, restricted to, the mountain environment. Plant and animal species that live in such conditions are particularly interesting ecologically because to meet the prerogatives of survival and reproduction requires a strategy of adaptive responses.

Relief of Ireland. From F.H.A. Aalen, K. Whelan & M. Stout (eds) (1997) Atlas of the Irish Rural Landscape. Cork University Press.

But what about the physical framework of Irish mountains? What about their environmental conditions – the soils and climate? And finally, what kind of mountain flora and fauna characterises Irish eminences and where are the best places to encounter it?

Physical frameworks

Most Irish mountains and uplands are formed of the older and harder rocks, the most ancient dating from the Precambrian period some 600 million years ago. These are the schists and gneisses (formed mainly of quartz, feldspar and mica, differing from granite in the size, colour and configuration of the crystals) that were originally laid down as sediments in the seas prior to severe alteration by pressure and heat. The effects of these processes were to change radically the character of the minerals and particles that made up the sedimentary rocks. Also included amongst the oldest rocks are the granites, originating in the molten material spewed out from deeper sources some 400 million years ago and injected into the surface layers. Mountains built of these earliest rocks are found mainly in Donegal, west Mayo, west Galway and in the Leinster region – especially the Wicklow uplands. The granites of the Mourne Mountains, Co. Down, were formed 350 million years later. During the Cambrian period, slates and quartzites were born out of sedimentary marine muds and sands. These rocks are found mainly in north Wicklow, Wexford and at Howth in Dublin. More recently still, in the Ordovician period, shaly rocks with some sandstones and limestones, including some molten rocks that have flowed into them, formed in the sea as sedimentary depositions. These amalgams of rocks are found mainly in the southeast of Ireland.

The Devonian grits and sandstones, often called ‘Old Red Sandstones’, and principally made up of fresh or marine water deposits, form the bulk of the Cork and Kerry highlands. Closer to us still, Carboniferous limestones, the result of deposition of millions of tiny calcareous shells and marine creatures in warm tropical seas around 300 million years ago, line the floor of the Central Plain, while in the Burren, Co. Clare, these limestones thrust up to produce grey rounded hills. In Co. Sligo the Benbulbin mountain range has been carved from great thicknesses of such limestones. As to the most recent Irish mountains, the extensive upland plateau in Co. Antrim and eastern Derry, they are the result of outpourings of lava belched up from underground sources some 65 million years ago.

The largest continuous upland area in Ireland is in Co. Wicklow where the granite hills higher than 300 m range over 520 km² and peak at 925 m on Lugnaquillia Mountain, which, unlike most of the other parts of the Wicklow uplands, has retained its Old Red Sandstone capping. The original body of the Wicklow Hills consisted of sandstones, grits and conglomerates that were laid down in an ancient sea during the Ordovician period. About 400 million years ago a large mass of hot molten granite was extruded from the earth’s belly. This heaving mass pushed the overlaying rocks upwards and humped them into a southwesterly aligned dome. Later on the sandstones and other slatey rocks were eroded away, a few lingering as marginal flanks to the hills, exposing the granite core that now forms the greatest area of granite in Ireland or Britain.

Further south in Cork and Kerry it is the hard Old Red Sandstone rocks that have endured. Their limestone covering was stripped off after all the rock layers were thrust up by a gigantic lateral earth movement some 300 million years ago, and folded in a series of ridges, aligned west-east. The intervening valleys, however, retain some of the surviving limestone. Towards the western side of this mountain mass are the Macgillycuddy’s Reeks, Co. Kerry. These host amongst a cluster of tall conical peaks, Ireland’s highest mountain, Carrauntoohil, rising to 1,039 m, to the east of which are the famous lakes and mountains of the Killarney National Park.

The structural geology of Ireland. From J.B. Whittow (1974) Geology and Scenery of Ireland. Penguin Books, London.

Table 3.1. Sequence of events and dates for the geological history of Ireland. From J.B. Whittow (1974) Geology and Scenery of Ireland. Penguin Books, London.

The Galway and Mayo highlands are also the result of convulsions that took place during the Caledonian mountain-building period some 400 million years ago. Hard granites in the south of Connemara and quartzites, gneiss, Silurian slates and shales in the north were pushed upwards to create hills and mountains. The Twelve Bens are made up of quartzite surrounded by Silurian schists and separated by valleys covered with blanket bog. Further north, over the Killary fjord, Co. Mayo, lies Mweelrea, the highest mountain in the west of Ireland (814 m), north of Brandon, Co. Kerry. The coastal cliffs at Slieve League, Co. Donegal, the highest sea cliffs within Ireland and Europe, plunge into the Atlantic from a height of 595 m. On the steep northeastern and landward face, one of the richest assemblages of alpine flora in Ireland looks out over blanket bogland and the cold, desolate Lough Agh below.

Rainfall, soil and environmental conditions

Levels of rainfall and humidity are much elevated on Irish mountains. The prevailing westerly winds are moisture-laden as they hit the west coast after travelling across several thousand kilometres of Atlantic Ocean, hence the often substantial and persistent falls of rain. Published figures from the highest recording station, set at 308 m at Ballaghbeama, Co. Kerry, show 396.5 cm of rain for the year 1960. At another station in Co. Kerry, at the Cummeragh River, 540 m above sea level, a total of 68.6 cm of rain was logged for just the month of December 1959, more than the average annual fall on the east coast. Further up the west coast at Kylemore, Co. Galway, close to sea level, the average over a 16 year period was 207.7 cm per year. At nearby Delphi, Co. Mayo, on the lee side of Mweelrea, rainfall of 254 cm per annum is not unusual, while in the wettest spots of Kerry and Galway precipitation can be as high as 250 cm per year.³ Such high rainfall encourages the development of boggy wet acidic soil and induces the leaching of nutrients. Still more important is the frequency of precipitation. The mountains of Donegal, Mayo–Galway and Kerry–Cork experience over 220 ‘wet days’ each year (a wet day is a period of 24 hours with precipitation of at least 1 mm).

Unfortunately no temperature readings are available from Irish mountains. However, for every 150 m rise in altitude the temperature decreases by approximately 1°C, so temperatures at any altitude may be estimated from isotherm maps corrected to sea level. For instance, at a height of 1,000 m the air will be at least 6.7°C colder than at sea level. The increased wind speed at the top of mountains will drop the temperature even further – a phenomenon known as the wind chill factor. Below freezing temperatures are encountered in winter as a thin white mantle covers the summits. On the country’s highest mountain, Carrauntoohil, snow can fall and lie for six months of the year, from November to early May⁴, while on Mweelrea there may be snow around the summit for at least 20 days each winter.

Despite some extremes, the Irish climate is essentially mild, especially in the southwest. The mean daily air temperature recorded at Valentia Observatory, Co. Kerry, 1951–80 was 10.5°C, the highest figure from eight stations throughout Ireland. The coldest months were December (mean 7.7°C), January (6.6°C), February (6.5°C) and March (7.8°C). The mean annual number of days on which ground frost was recorded at Valentia Observatory 1960–84 (grass minimum temperature less than 0.0°C) was 38.6, approximately one third the number of days recorded at eight other stations throughout Ireland.⁵

Wherever drainage is poor in the uplands or on the mountains, acid peat bog develops. This is one of the three main vegetation types typical of Irish high ground, the others being grassland and heath. On the exposed mountain summits, a more montane community is often present. Within the mountain environment there are many habitats hosting different groups of liverworts, mosses, ferns and flowering plants. Boulder screes, gullies, streams, vertical cliff faces, ridges and even snow fields that persist for several months each year provide specialist niches for the 58 species that are characteristic of Irish mountains and uplands.

Average annual rainfall 1951–1980. From Rohan⁵.

The occurrence of calcareous outcrops, pockets of base-rich rocks such as mica schists, or out-flushings of mineral rich waters from deeper below, have dramatic impacts on the mountain flora, allowing many species to flourish profusely in an otherwise acidic environment. The largest limestone outcrop and mountain range in Ireland is Benbulbin, Co. Sligo. Benbulbin ascends vertically in the upper parts to a blanket bog-covered plateau with a maximum altitude of 526 m. On first sight this smothering of peat appears to defy ecological good manners, sitting on top of limestone rock which should, according to conventional rules, be supporting a community of calcicole or lime-loving plants. Peatland communities, made up of more astringent calcifuge or lime-fleeing species are normally found in lime poor habitats. The dramatic cliff walls, hanging over the lowlands below, are where most of Benbulbin’s renowned arctic-alpine flora is to be found.

Burning and grazing are traditional agricultural practices that have moulded and shaped the upland and mountain plant communities for centuries. However, since Ireland joined the European Union in 1973 the number of sheep grazing the mountains has increased dramatically, prompted by generous subsidies and premiums from Brussels and the government. Numbers nearly trebled from 3.3 million in 1980 to 8.9 million in June 1991. The heavy grazing intensity steadily eradicates the dwarf shrubs, such as heather and other ericales, and allows their replacement by grasses and, in dry places, bracken. Under high densities of animals, peat also suffers compaction which alters its oxygenation, leading to a premature death of the vegetation skin. The mechanical trampling leads to the disappearance of peat mosses, Sphagnum spp., whose water absorbency is crucial for the ecology of the bog. Tussock-forming sedges are the most resistant to the sheep’s aggression. The compaction of peat and the loss of Sphagnum, compounded by the removal of vegetation by incessant grazing, leads to a faster runoff of water down the mountain slopes.⁶ During a limited ecological survey in Co. Mayo, conducted nearly eight years ago, a total of 66 selected blanket bog sites were visited with the objective of identifying the more intact areas for conservation. Twenty-five, or 38%, of the sites, covering some 12,500 ha, contained significant areas that were overgrazed. Several sites among the 25 were completely destroyed. Indeed, it is estimated that in the case of very eroded blanket bog, rock-bare in places, it would take between 5,000 and 10,000 years for just 2.5 cm of soil to be regenerated.⁶

How the precious alpine and arctic flora has fared under this new regime of unabated encroachment is not known. It is easier to assess the declining populations of moorland breeding birds such as the red grouse, merlin, hen harrier, and even of the Irish hare. Other impacts on upland and mountain flora come from burning, reclamation of moorland through drainage, afforestation and the application of a wide range of chemical fertilisers, often by air.

Erriff Valley, Co. Mayo. Excessive grazing by sheep (A. Walsh).

The arctic-alpine flora

David Webb, doyen of modern Irish botanists, in a critical review of the flora of Ireland in its European context, concluded that there were 16 genuine arctic-alpines in the Irish flora.⁷ His criteria were that the plant ‘must be fairly widespread in the arctic and sub-arctic regions of Europe and must reappear at high altitudes (at least up to 2,000 m) in the Alps (often also in the Pyrenees). But it must be scarce or absent in the intervening areas for otherwise it becomes merged in the main mass of northern continental species.’ He excluded any species that was found at low altitudes south of about 54°–55°N and any occurring in Central Europe at altitudes below 800 m in the immediate neighbourhood of high mountains. Using these criteria he excluded the following species often described by many different authorities as arctic-alpines: alpine saxifrage, marsh saxifrage, northern rock-cress, stiff sedge, spring sandwort, bearberry, cowberry and spring gentian. While all the these species are arctic they do not fulfil Webb’s other arctic-alpine criteria. According to Webb the spring gentian is a well-known example of incorrect geographic placement. It is often assumed – because of its association with mountain avens in the Burren, Co. Clare, and in the high Alps – to have an identical geographic distribution to mountain avens which is a true arctic-alpine. However, the spring gentian is common in central and southern Germany below 800 m and also present in the karst country of Slovenia. Moreover, its representation in the Arctic is extremely meagre, being confined to a few locations in arctic Russia.

The arctic-alpine species occurring in Ireland, according to Webb’s criteria, are alpine lady’s-mantie, fringed sandwort, hoary whitlowgrass, mountain avens, chickweed willowherb, mountain sorrel, alpine meadow-grass, alpine bistort, roseroot, dwarf willow, alpine saw-wort, yellow saxifrage, purple saxifrage, starry saxifrage, moss campion and alpine meadow-rue. Webb also identified the following seven ‘alpine’ and ‘arctic-sub-arctic’ species, some with reservations: alpine: recurved sandwort; alpine (with reservations): large-flowered butterwort and Irish eyebright; arctic-sub-arctic. Scots lovage and oysterplant; arctic-sub-arctic (marginal): water sedge and alpine saxifrage.

The cloudberry, which has one station in Ireland on the Tyrone side of the Tyrone/Derry county boundary in the Sperrin Mountains, is usually thought to deserve in other texts the appellation ‘arctic-sub-arctic’ but, according to Webb, it is too widespread south of the Baltic, in north Germany and Poland, to qualify for that status. Therefore it is not included in any of the above categories. All the seven ‘marginal’ species listed above are presumed to be arctic in origin, and to have spread southwards in front of the glaciers without going far enough to get up high in the Alps, Pyrenees or Carpathians.

In his seminal paper ‘On the range of flowering plants and ferns on the mountains of Ireland’ the great Irish botanist Henry Chichester Hart considered that 13 species qualified as ‘alpines’ but without giving precise criteria. Hart was perhaps the most intrepid and adventurous of all explorers of Irish mountains with an unrivalled knowledge of Irish mountain flora. His list of alpines is important as a tool for comparing the floras of various mountains throughout Ireland: cloudberry, northern bedstraw, the hawkweed Hieracium anglicum, bearberry, cowberry, juniper, stiff sedge, blue moor-grass, parsley fern, holly fern, green spleenwort, lesser clubmoss and quillwort. None meet the Webb criteria of arctic-alpines.⁸

Alpine and arctic-alpine species are both rare and thinly spread throughout the country. Concentrations occur principally in the coastal counties, where most mountain ranges are found, with more species in the northern than in the southern parts of the island. The elevation at which they occur increases from the north to south as temperatures are higher in the south and thus more elevation is required to find a suitable cold spot. Of 17 species analysed by Praeger that were common to the Donegal–Derry and Kerry–Cork mountains, the mean lower limit in the north was 168 m while in the south it was approximately double that, illustrating one of the few impacts of latitude on the Irish flora. A similar comparison for 12 species found in western and eastern Ireland, showed that the mean lower limit was 326 m in Down–Wicklow compared with 219 m for Mayo–Galway, a reaction thought to be due to the wet and windy conditions along the western seaboard which effectively lower the temperatures.³

One of the curious features of alpine plants in Ireland is that many of them do not remain perched high up on the mountains but descend down to sea level and into the countryside, sometimes well away from their alma mater. In fact, even when on the mountains they prefer reasonable to dizzy heights. Praeger looked at their distribution in relation to elevation in Ireland and found that the number of species increased steadily as one travelled towards the summit with a maximum number of 19 species at 300 m above sea level. Thereafter their numbers decreased equally steadily.⁹ Praeger also noted that 16 of the 42 so-called Watsonian ‘highland’ plants (including arctic-alpines and alpines) occur down to sea level. In fact, most Irish summits have a paltry flora, generally almost devoid of alpines and arctic-alpines. These are happier growing at lower levels, in more favourable habitats where, for instance, there are outcrops of mineral-rich rocks, and the ground is free from tall vegetation.

A few of the alpines do not give in to this ‘erratic’ behaviour but, as Hart observed, they are not numerous: ‘Of those more thoroughly alpine plants which never descended to sea level in these mountains (or elsewhere in Ireland), only three are ever met with on the exposed summits or outer ridges.’⁸ They were alpine clubmoss, dwarf willow and stiff sedge. As to the species that will occur very high up, Praeger listed eight that persisted above 914 m on the Macgillycuddy’s Reeks, Co. Kerry.³ The species, with their maximum recorded altitudes in Ireland were: starry saxifrage (1,036 m), alpine hair-grass (1,027 m), stiff sedge (1,006 m), green spleenwort (960 m), mountain sorrel (960 m), roseroot (960 m), alpine meadow-grass (945 m) and dwarf willow (930 m). These, together with the alpine clubmoss, could be taken as the hard core of the Irish alpine and arctic-alpine flora.

Juniper is common on some mountains, where the subspecies Juniperus communis subsp. nana is mainly found on siliceous rocks, always growing prostrate.

Most Irish summits – generally covered by thin peat or just bare soil and stones – make drab spots for flowers, whether or not of the alpine kind. One wishing to find ‘summit’ flowers might well have to abseil down along the north-facing cliffs and scarps in order to peruse the nooks and crannies and the rock overhangs. Praeger – himself a fearless cliffhanger – listed 13 of these core ‘summit’ plants, based on an analysis of the flora of the seven highest Irish peaks. They were tormentil, heath bedstraw, bilberry, heather, sheep’s sorrel, crowberry, heath rush, great wood-rush, hare’s-tail cottongrass, tufted hairgrass, sweet vernal-grass, sheep’s fescue and fir clubmoss.

Four maritime plants, which could be considered ‘sea-loving’, are frequently encountered growing on mountains at high altitudes in the company of alpine species. The first, thrift, a common coastal species, occurs on most of the highest mountains in Ireland. Hart encountered it at or close to the summits of the Mayo and Galway mountains – on Nephin and Mweelrea, Co. Mayo, both at 805 m, Croagh Patrick, Co. Mayo, at 675 m, and in the Twelve Bens, Co. Galway, up to 686 m. At Corraun, Achill Island, Co. Mayo, thrift grows abundantly on siliceous rocks at sea level, but then appears only above 366 m. It also grows at the summit of Carrauntoohil, Co. Kerry, at 1,039 m. Thrift adopts different shapes according to environmental stress. In its mountain habitat, subjected to grazing or particularly dry conditions it contracts into a dense cushion with short leaves and stems. Without stress, especially flourishing at sea level, it takes on a more straggly, less defensive aspect.

The sea plantain grows on the highest Galway and Mayo mountains up to 792 m. A curiously stunted variety, with broad leaves and a stem 3.8 cm high, was found by Hart at 701 m on the Askaheeraun ridge, Mweelrea, and on the summit of Ben Creggan (693 m), Co. Mayo. In the Twelve Bens the species ascends to 518 m. On Achill Island, Co. Mayo, it occurs continuously from the summit of Slievemore (671 m) to the sea-drenched cliffs below. This plantain also grows inland at low altitude levels, breaking with convention when it occurs around the shores of Lough Derg – some 40 km from the coast. It is also on the limestone pavements around Loughs Corrib, Mask, Carra, and Conn, Co. Mayo.

There are also outposts of maritime plants, including the two already mentioned and the following species, at the Killarney lakes, Co. Kerry, and around the shore of Lough Neagh in Northern Ireland. The white-flowered sea campion, normally found growing on sea cliffs, islands and coastal shingle, occurs on most of the Galway and Mayo mountains – on Croagh Patrick at 764 m, Mweelrea and Benlettery, Connemara, at 580 m and Birreencorragh, Co. Mayo, at 610 m. The common scurvygrass, common in dry salt marshes and coastal areas is also found in its subspecific form Cochlearia officinalis subsp. alpina in the Galty Mountains, Co. Tipperary, as well as joining the other three species already mentioned on the Binevenagh cliffs, Co. Derry. Finally, Hart also mentions a fifth species, the English stonecrop, as a member of the group which displays such aberrant distribution. A plant of rocky places, very frequently near the sea and rarely inland, this stonecrop is found on the Cork and Kerry mountains up to 801 m while in Wicklow it occurs up to 594 m and in Donegal up to 259 m.

Sea campion in its more natural lowland and coastal habitat, Little Saltee Island, Co. Wexford.

A plausible explanation for the mountain ascent of these maritime plants was put forward over 100 years ago by the Scottish naturalist Buchanan White who argued that they were part of the late glacial flora that was forced to migrate ahead of the expanding woodland cover during the Atlantic period. As the upper parts of the mountains were generally the only tree-free areas this is where the plants retreated to and survived until today.¹⁰ Work carried out by Watts on the flora of the Quaternary period in Ireland has shown that several species – likely candidates for migration up the mountain slopes – could be identified from the interglacial deposits at Kilbeg, Co. Waterford.¹¹ The records included alpine meadow-rue (fruits), alpine clubmoss (spores), juniper (pollen, seed, needle), lesser clubmoss (micro and megaspores) and the sea plantain (pollen). Once established on mountain tops these, and many other species, found themselves safe from the re-advancing glaciers when another cold spell clamped down on the Irish landscape.

Principal locations for alpine and arctic-alpine species

The Wicklow Mountains and uplands

The Wicklow Mountains and uplands are the most extensive area of granite in Ireland and greater than any in Britain. The region is of considerable natural beauty and topographical diversity, where glacier-scoured river valleys and glens clothed in broadleaved woods host enchanting lakes; where large tracts of blanket bog are presided over by granite summits and dominated by Lugnaquillia Mountain (925 m); where there is a swaddling coverage of coniferous plantations, and where cliffs and corries are frequent. The vegetation found there is characteristic of the upland and mountain habitats of many other sections of Ireland.

During the winter of 1901–2 George H. Pethybridge, a young English plant physiologist, teamed up with Praeger to start a survey of the vegetation lying south of Dublin, including the Wicklow uplands.¹² According to White this was the start of the modern investigations of Irish vegetation.¹³ Pethybridge & Praeger distinguished four zones: (i) the lowest, or the littoral zone which is of little or no interest to botanists; (ii) farmland, that merged into (iii) hill pasture at about 275 m (with gorse to begin with and western gorse at higher altitudes) before giving way to (iv) heather moorland which developed at around 380 m and continued upwards to the highest – flora-poor – summits.

The dry heath of the hill pasture, dominated by western gorse, heather and bell heather, is typically found in Counties Dublin and Wicklow from about 70 m to 400 m. The dry heath community was not described in detail and had to wait for its first precise description by Clark in 1968.¹⁴ Where the heath had been burnt about four years previously, Clark found that western gorse formed a mat of vegetation 20–30 cm tall. In areas untouched by fire for more than ten years the gorse was taller – 30–50 cm – and often more open, leaving room for bell heather, heather and a sparse herb layer of mainly sheep’s fescue and some common bent.

Western gorse, abundant in eastern Ireland and more local in the west, is characteristically found in coastal, lowland and sub-montane habitats, especially in the Wicklow Mountains where it occurs typically in the upper hill pasture areas before the vegetation changes to heather moorland at about 400 m. The somewhat similar but much taller gorse (also known as furze or whin) occurs typically at lower altitudes in the Wicklow hills and elsewhere in Ireland.

Higher up in the heather moorland Pethybridge & Praeger described areas, especially on the flat summits, dominated by deergrass and common cotton-grass. On the flat summit of Lugnaquillia Mountain they found a thin skin of vegetation, dominated by the woolly fringe-moss, bilberry, heath bedstraw, heath rush, stiff sedge, the moss Polytrichum commune and colonies of the alpine clubmoss.

The Wicklow uplands are a disappointment for mountain plants when compared with some of the highland sites in the northern and western counties. Both the arctic-alpine roseroot and the mossy saxifrage, first reported in 1897 and 1927 respectively, have not been found recently and are feared to be extinct.¹⁵ St Patrick’s cabbage and fir clubmoss are found on the mountain itself. The occurrence of St Patrick’s cabbage is an oddity because Lugnaquillia Mountain is very much an outlying station, far away from the main centre of distribution in Cork and Kerry. Some 13.5 km northeast of Lugnaquillia Mountain a rocky escarpment at 557 m overlooking Lough Ouler, near Tonelagee, hosts alpine lady’s-mantle and, together with a site on the Brandon Mountains, Co. Kerry, these are the only localities where the species has been seen in Ireland since 1970. Alpine lady’s-mantle is tall for an arctic-alpine, reaching up to 20 cm. Its leaves, unlike those of its close relative lady’s-mantle, are divided to the base and underneath are silvery grey with hairs. The flowers are small (3 mm) and pale green. Also growing on the Lough Ouler escarpment is alpine saw-wort which belongs to the daisy family. It is a short, stout perennial that looks somewhat like a thistle with fragrant purple flowers in August-September. Both alpine lady’s-mantle and alpine saw-wort were first recorded in Ireland from the mountains of ‘Keri’ by the Welsh antiquarian and naturalist Edward Lhwyd in 1699. Alpine saw-wort has now been reported from 26 sites in Ireland, at altitudes over 300 m. It is thought to be declining.¹⁶

Gorse, furze or whin, characteristic of the rough grassland or heaths of the lower parts of the Wicklow Mountains.

A re-survey of the area studied by Pethybridge & Praeger was carried out 50 years later by John J. Moore, champion in Ireland of the study of plant communities using the mathematical and quantitative phytosociological methods of the German botanist Braun-Blanquet.¹⁷ Moore redefined the plant communities and found that they had remained remarkably stable over the years, the main changes being an advance of bracken, extending its range by a maximum distance of 150 m, and to a lesser extent of western gorse, into abandoned farmland. A widespread reduction in the frequency of the woolly fringe-moss in the high land was also observed.

The Galway and Mayo highlands

The great metamorphic rock masses of west Galway and Mayo stretch some 120 km from south Connemara to north Erris in one of the wildest and most beautiful parts of Ireland. In the south, the Twelve Bens stand out as rugged steep-sided mountains with quartzite peaks, many of which are higher than 600 m. Although the region is described as the Twelve Bens, there are, as pointed out by Hart, 17 more or less detached peaks from about 457–731 m.⁸ Mica schists appear in the western peaks and through weathering break down to provide the more attractive calcareous soils on which many mountain species thrive in an abundance rarely attained elsewhere in Ireland. To the east of Lough Inagh, defining the eastern boundary of the Twelve Bens, lie the Maumturk Mountains, a large ridge of quartzite, peaking at 702 m. Blanket bogland, characterised by purple moor-grass which grows with extreme luxuriance, dominates the Connemara slopes to about 300 m before giving way to vegetation in which heather is the key species.

Irish mountains and uplands are invariably bleak, generally bereft of woody vegetation above 300 m. Here, in the neighbourhood of the Killary Harbour, Co. Mayo, the siliceous soils, derived from Silurian slates and shales, offer little opportunity for a diverse vegetation.

Bengower is one of the most southerly peaks of the Twelve Bens and its summit reaches 666 m. The vegetation of the north-facing slope at 550 m was examined in the early 1960s by Ratcliffe, the first to give a detailed description of the flora of that particular stretch.¹⁸ No remarkable specimens were found apart from the liverwort Adelanthus lindenbergianus, a southern hemisphere species first discovered at Slievemore, Achill Island, Co. Mayo, in 1903 by H. W. Lett – when it was mistakenly named as an endemic, A. dugortiensis – and only known from these two stations and from Errigal and Muckish Mountains, Co. Donegal.

Praeger wrote that the best ground for the botanist is Muckanaght (654 m) in the centre of the Twelve Bens, where ‘an oasis of schist in a Sahara of quartz’ encourages a ‘very pretty colony of alpine plants’.³ Alpine meadow-rue, purple saxifrage, mountain sorrel, alpine saw-wort, dwarf willow and holly fern grow here. Ever since Wade first published a list, albeit slender, of the flora of Connemara – in which he recorded the first discovery in Ireland of the American species pipewort¹⁹ – Connemara has attracted a continuous procession of distinguished botanists and naturalists. The most extensive botanical investigations of the Connemara mountains were carried out by Hart, whose 1883 paper remains a standard text today.⁸ Colgan followed soon afterwards with a less ambitious work² and Praeger was also a frequent visitor from the early part of this century.³ More recent investigations on mountain plants have been published by Roden²⁰, while Webb & Scannell provide an account of all Connemara plants in Flora of Connemara and the Burren.²¹

Slievemore, Achill Island, Co. Mayo, in the distance.

Mweelrea Mountain, Co. Mayo

The Irish name of this highest mountain in Connacht – An maol riabhach: ‘the grey bald mountain top’ – fits it perfectly. Built of Silurian slates and shales chiefly with sandstones, schists and conglomerates, it presides boldly over a remote corner of southwestern Mayo, overlooking Killary Harbour. To the north are the islands of Clare and Achill; to the east the more stark grey mountain of Ben Gorm (700 m) and the Sheeffry Hills (highest point 762 m). Whilst in many respects a smooth and accessible mountain, Mweelrea has high vertical cliffs on the inland side. As observed by Hart when he visited the summit (814 m) in the summer of 1882, the prospects for alpine plants are raised but not completely fulfilled by ‘the long ranges of precipices, ridges and gullies ending in ravines with sheer sides and dangerous nooks’. Once he got to the top he found the following, amongst other species: St Patrick’s cabbage, starry saxifrage, roseroot, the hawkweeds Hieracium anglicum and H. iricum, bearberry, mountain sorrel, dwarf willow, stiff sedge, tufted hair-grass, alpine clubmoss, lesser clubmoss and quillwort.

During a visit in September 1961, while examining the cliffs at the head of the great north corrie at nearly 790 m on the east spur of Mweelrea, Ratcliffe discovered the liverwort Jamesoniella carringtonii, widespread in the Scottish Highlands but never previously recorded in Ireland. On Mweelrea it was found growing sparingly on broken cliffs and ledges amongst tufts of other liverworts – Herbertus aduncus subsp. hutchinsiae, Pleurozia purpurea, Bazzania pearsonii, B. tricrenata, Scapania ornithopodioides, S. gracilis and Plagiochila spinulosa.¹⁸

Mweelrea Mountain, Co. Mayo. The scree slopes support little vegetation.

Macgillycuddy’s Reeks and Brandon Mountain, Co. Kerry

The Macgillycuddy’s Reeks in Kerry reach 1,039 m at their highest point and are made up of a number of other summits above 900 m. Despite their promising aspect, these mountains are botanically a disappointment. The arctic-alpine and alpine species recorded by Praeger above 914 m included alpine scurvygrass, roseroot, starry saxifrage, mountain sorrel, dwarf willow, stiff sedge, alpine hair-grass, green spleenwort and alpine clubmoss. The hoary whitlowgrass, another arctic-alpine, can be found lower down but the best places to encounter the arctic-alpine and alpine species are the cliffs south of Lough Eagher at the head of Cumloughra Glen, and the series of coombs – steep cliffs with boulder scree – north of Lough Gouragh. The Kerry speciality, the strawberry-tree, is found at an altitude of 160 m, while the delicate Tunbridge filmy-fern and Killarney fern make it to 600 m and 460 m respectively.²²

Northwest of the Macgillycuddy’s Reeks, the Dingle peninsula sticks out into the Atlantic like a long, ridged finger built of sandstones and slates with its more geologically complex northwestern tip fringed with dramatic sea cliffs. The highest point there is Mount Brandon (952 m). Falling away from the eastern side of the summit the cliffs drop into a series of lakes, sometimes called paternoster lakes – they are strung out like rosary beads – each one lower than the previous one. Growing near the highest lake, at 715 m, are alternate water-milfoil and quillwort, at their most elevated stations known in Ireland. Praeger, writing in the Botanist in Ireland, reckoned that these cliffs were a repository of interesting species: ‘the richest alpine ground in the country’. Expeditions by Curtis between 1988 and 1990 in search of alpine bistort have brought renewed evidence of their richness.²³ The Mount Brandon range, located in one of the remotest areas of Ireland and set in stunning scenery, would certainly repay more intensive investigations by botanists.

The arctic-alpines recorded, apart from the bistort, include alpine lady’s-mantle (found only here, at one other site in south Kerry and near Lough Ouler, Co. Wicklow), alpine meadow-grass (also only here and in the Benbulbin mountain range, Co. Sligo), alpine meadow-rue, alpine saw-wort, dwarf willow, yellow saxifrage, purple saxifrage, starry saxifrage, mountain sorrel and the alpine species, holly fern. The holly fern, like two other ferns present – the parsley fern and green spleenwort – is one of the true mountain ferns, and is usually found growing in crevices of base-rich rocks. The victim of unscrupulous plant collectors in the past, it is restricted to western Ireland where it has been recorded from seven sites, the most easterly being in Co. Fermanagh.¹⁶

Caha Mountains, Counties Cork and Kerry

The Caha Mountains, made up of a great ridge of Old Red Sandstone, lie some 40 km southwest of Macgillycuddy’s Reeks. The northern side presides over the majestic Kenmare Bay while to the south they slope down to Ban try Bay. The Cork–Kerry border runs through the high ridge, Hungry Hill being the highest point at 685 m. The interest of Caha rests with a most exciting discovery, made in July 1964, of the small and delicate recurved sandwort found growing in narrow cracks of bare outcrops of Old Red Sandstone slabs east of Knockowen (658 m) and to the north-northeast of Cushnaficulla summit (594 m).²⁴ About 1,000 plants were found at each of the locations. The Caha Mountains are the only known station in Ireland for this sandwort and it has never been recorded in Britain. The plant is a short and small tufted perennial with prostrate to semi-erect woody stems, forming a compact cushion of leaves. It is distinguished from the somewhat similar spring sandwort, also found on mountains (locally in Clare, Antrim, Derry and on the Aran Islands, Co. Galway) by having mostly down-curved leaves and 5–7 veins on the white sepals. Its white flowers, which seem large in relation to the overall plant size, bloom from June to August.

How is it that recurved sandwort only occurs on the Caha Mountains and nowhere else in Ireland or Britain? The nearest recorded station is in the Serra de Gerez in Portugal from where it extends through the Pyrenees and Alps and further eastwards, in suitable siliceous mountain ranges, to the Romanian Carpathians.⁷ Geological evidence – no signs of glacial smoothing on the stone slabs: their present surface corresponds exactly to the bedding plane of the sandstone and knowledge of known movements of the ice sheets in the area – shows that the summits of both Knockowen and Cushnaficulla were spared the rigours of the ice sheets and overlooked the glaciers moving around below. Clearly the peaks were ice fee and could have acted as refugia for the sandwort during the last and earlier glaciations.^25,26 Webb was of the opinion that the recurved sandwort was present in Ireland long before the last glaciation.⁷

While the recurved sandwort does not fall into the category as one of the 16 arctic-alpine species in Ireland, it is the only true ‘alpine’ species in the country according to the criteria of Webb as laid out earlier in this chapter. The presence of this sandwort on the Caha Mountains strengthens the argument that many species of the Irish flora are not recent immigrants but members of a more ancient flora that was able to survive in glacier-free areas during the Ice Age.

Benbulbin mountain range, Co. Sligo

These mountains are part of a Carboniferous limestone plateau that has survived the gradual down-wearing of the surrounding landscape over millions of years. The whole area, reaching 450–600 m in height, extends over about 500 km² between Lough Gill in Co. Sligo and Lough Melvin in Co. Leitrim. There is no evidence from glacial deposits or markings by moving ice sheets to suggest that the mountains were covered by ice during the main phase of the Midlandian cold stage to the end of the Drumlin phase of the Midlandian cold stage (79,000–13,000 years ago), so they would have been available as refugia for flora and fauna when the ice sheets tore up and scoured the lower ground, destroying all forms of life.

Evidence that some of the existing Benbulbin mountain flora thrived at lower levels many thousands of years ago comes from plant materials identified from interstadial deposits of mud and moss peat uncovered beneath a drumlin at Derryvree, Co. Fermanagh, and from silt, exposed below glacial till by a river slicing through a drumlin at Hollymount, near Lisnaskea, Co. Fermanagh. They date from before 30,000 and 40,000 years ago respectively. Analysis of the plant materials indicate that the vegetation of the time was characteristic of a cold climate in a tundra landscape. The species identified included the following arctic-alpine and alpine plants: dwarf willow, mountain sorrel, fringed sandwort, purple saxifrage and mountain avens.²⁷ Today the cliffs and screes of Benbulbin and surrounding mountains are one of the most important habitats for these species in Ireland, and include the only known site for the fringed sandwort. It is highly likely that in the face of approaching ice sheets these and other species moved up the mountain to take refuge from the advancing ice glaciers. Whether they survived the long period of polar desert conditions, with intense cold, is less certain.

Benbulbin, Co. Sligo. An uplifted carboniferous limestone plateau with dramatic cliffs, the home of many rare arctic-alpine plants.

Benwiskin (514 m), Co. Sligo, as dramatic as the nearby cliffs of Benbulbin (F. Guinness).

The best known part of the Benbulbin mountain range is the spectacular western spur where the eponymous summit rises to 526 m with its high, sculptured profile. Two large, cliff-walled valleys, each with a lake – Glencar Lough in the south and Glenade Lough in the east – bisect the two mountain lobes and provide topographical diversity to an already very dramatic landscape. The Benbulbin area, extending from Co. Sligo to Co. Leitrim, is so extensive that it would take a botanist at least seven days, working at a feverish pitch, to do the place justice. There are, however, two ‘hot spots’ for the arctic-alpines and alpines.

The first area is the cliffs of Annacoona in the Gleniff Valley, guarded at the northwest entrance by Benwiskin (514 m) which rises to a remarkable pinnacle, like the Matterhorn, surveying the landscape. The Annacoona cliffs face northeast, overlooking the great cirque of Gleniff, gouged out by a glacier. On a still summer’s day the croaking of ravens, rolling around and playing aerobatics along the steep cliffs, the occasional shrieking of a peregrine and the bleating of sheep are the only sounds in this otherwise silent valley. On the cliffs at Annacoona the arctic-alpine flora starts from an altitude of about 244 m upwards. The rarest species is fringed sandwort which has its home here on the upper sections of the limestone cliffs, between 300 and 550 m. This small and deceptively dainty, white-flowered and slightly hairy perennial is a member of the Caryophyllaceae or chickweed family and was first discovered by the eminent Welsh antiquarian and natural historian Edward Lhwyd on one of his visits to Ireland in 1699. He recounted the discovery in a letter to Tancred Robinson, a great friend of the British botanist John Ray: ‘In the same neighbourhood on the mountains of Ben Bulben and Ben Buishgen, we met with a number of the rare mountain plants of England and Wales, and three or four not yet discover’d in Britain.’²⁸ Irish specimens of fringed sandwort were assigned to the special endemic subspecies Arenaria ciliata subsp. hibernica by Ostenfeld & Dahl in 1917 who also separated off two other subspecies, A. c. pseudofrigida found in arctic Europe and Arctic sandwort A. c. norvegica found in Shetland, arctic Europe and America.²⁹ There is one record of A. c. norvegica from the Burren in Co. Clare but it has never been rediscovered despite repeated attempts by many botanists. Endemic species, or subspecies, are restricted to a specific geographic region and have evolved the differences that separate them from their close relations due to their isolation, or in response to soil or climatic conditions.

Annacoona is the only known Irish station for alpine saxifrage, first discovered here by the botanist John Wynne in 1837. Its leaves are purple underneath and it has a very hairy inflorescence with white petals and reddish sepals. Within the Benbulbin area alpine meadow-rue is also confined to Annacoona. Amongst the species listed by Praeger found on the cliffs and escarpments, the following occur in profusion:³ alpine scurvygrass, hoary whitlowgrass, mountain avens, yellow saxifrage, mossy saxifrage, brittle bladder-fern, green spleenwort, limestone bedstraw and common milkwort. More locally abundant are lesser meadow-rue, moss campion, purple saxifrage, upland enchanter’s-nightshade, mountain sorrel, tea-leaved willow, blue moor-grass, holly fern, beech fern and Irish eyebright. Raven in Mountain Flowers writes that the Benbulbin eyebrights he saw on his visit resembled some, but not all, of the specimens of Euphrasia lapponica he had seen in isolated populations in northern Scandinavia¹. The following species are rare: Welsh poppy, wood vetch, several hawkweeds including Hieracium hypochoeroides, cowberry, alpine bistort, dwarf willow, juniper, stiff sedge, maidenhair fern, large thyme and alpine meadow-grass (found only here and on the Brandon Mountain, Co. Kerry). Isolated trees or small clumps of them, firmly rooted in the vertical cliffs, are a curious sight – rock whitebeam, wych elm and yew are all present, only ever to be touched by birds and flying insects.

The other interesting place for arctic-alpines and alpines is a section of the north-facing cliffs some 5 km northeast on the Tievebaun Mountain, Co. Leitrim. The cliffs are northwest of Glenade Lough. The exciting section extends for about 800 m at an altitude of 213–366 m. Many species already growing at Annacoona are found here, together with the chickweed willowherb, a unique speciality of these precincts. First discovered here by R.M. Barrington and R.P. Vowell in 1884, it is a low, small, creeping, almost hairless willowherb with runners above the ground. The flowers are purplish-pink and the seed pods turn red when ripe. Partial to streams and wet places, especially dripping rocks, this willowherb has two sites at Glenade. The first is a wet cliff, where 100 plants grow in an area of about 25 m². The second occurs along a small stream where a 30 m stretch accommodates about 70 plants. Also at Glenade, on an inaccessible vertical cliff, is the northern rock-cress, at one of only two locations in Ireland, the other being a site in the Galty Mountains, Co. Tipperary.¹⁶ This rock-cress is a small, slightly hairy plant with lobed lower leaves and small white, sometimes lilac flowers born on flowering stems some 8–25 cm tall. The seeds are carried in a long flattened pod. Golden saxifrage is here, found in wet spots on the cliff between 215 and 366 m. It is low and loosely tufted perennial with spreading and creeping stems that are square. The flowers are small, yellowish and without petals. Wych elm and rock white-beam grow on the cliff face wherever they can get a toehold.

One curious feature of Benbulbin’s flat top, as previously mentioned, is its covering by a thick blanket of peat bog, with all the attendant peatland plants. Where the underlying limestone pokes up through the vegetable skin a calcicole flora develops including several alpine species. During the colonisation process several species of mosses, especially Breutelia chrysocoma, settle on the limestone pavement, thrive and proliferate, and they soon produce layers of humus which can then be colonised by the seeds of heather and other ericaceous species. The new arrivals draw most of their nutrients from the acidic moss humus rather than from the limestone below by ensuring that their roots grow initially upwards or horizontally.³⁰ Gradually the bog builds up, becoming more and more acidic with time, and the plants then exist on whatever nutrients they can draw from their own mounting pile of peat humus plus those that fall out of the sky with the rain.

Slieve League, Co. Donegal

‘One of the finest things of its kind’ was how Praeger described the mountain of Slieve League which brutally confronts the Atlantic Ocean at the end of the southwestern promontory of Co. Donegal. Made up of very old rocks – ancient schists, gneisses and quartzites laid down some 500 million years ago and then thrust up in the Caledonian upheavals – Slieve League rises to 595 m at its summit. It is essentially a quartzite peak, with some Carboniferous sandstone and even less limestone occurring on the summit. Like the Benbulbin mountain range it was almost certainly ice-free in days of glacier supremacy, a haven for arctic-alpine plants and other refugees. The southern side of the mountain has been truncated by the continual pounding of the Atlantic to form some of the most impressive cliffs in Europe. At sunset, the cliff structures, made mainly of quartzite and gneiss, glint and reflect the light in a way that signals their long and tortured history. On the north side of the mountain more cliffs plummet from about 460 m, equally dramatically, down to the dark and seemingly sinister Lough Agh that sits at an altitude of 245 m. Starting from the village of Teelin to the southeast, one of the best walks in Ireland can be had by ascending the summit including a bracing passage along a knife-edge ridge, appropriately named ‘One Man’s Path’. The northern precipice is one of the finest sites in Ireland for arctic-alpine plants and has attracted the attention of many distinguished botanists and naturalists for more than a hundred years. The number of arctic-alpine species is greatest here, and progressively declines southwards down the west coast and even more rapidly as one moves southwards along the east coast of Ireland.

Not only is the total number of arctic-alpine and alpine species on the north-facing cliffs of Slieve League the largest in the country but there are more species here than in any other similar habitat of comparable size in Ireland. Hart, who lived in Donegal and was at leisure to climb up and down Slieve League, reported many in his Flora of the County Donegal,³¹ thus supplementing earlier work.³² The species, listed again later by Praeger in The Botanist in Ireland include bearberry, green spleenwort, stiff sedge, mountain avens, dwarf juniper, alpine clubmoss, mountain sorrel, alpine bistort, holly fern, dwarf willow, alpine saw-wort, yellow saxifrage, purple saxifrage, starry saxifrage, roseroot, lesser clubmoss and alpine meadow-rue.

Slieve League cliffs, Co. Donegal.

H. J.B. and H.H. Birks, together with Ratcliffe, visited Slieve League in September 1967 when they explored the shattered and gully-seamed cliff above Lough Agh.³³ The most interesting site here is a north-facing outcrop of calcareous schistose rocks extending for about 91 m at an altitude of 400–460 m. They added the brittle bladder-fern and mountain everlasting to the list for the area as well as recording 29 bryophytes of interest. Most of these are characteristic of calcareous rocky outcrops and are generally widely distributed in Ireland, apart from the liverwort Gymnomitrion concinnatum. Two mosses were of particular interest. One was the rare oceanic Leptodontium recurvifolium, providing a link between its previously known Irish localities in Kerry, Galway and Mayo and the western Scottish Highlands. The other, Orthothecium rufescens, also provided a connection between the Scottish Highlands and its previously known Irish sites on the Carboniferous limestones of Sligo and Leitrim, and the Burren, Co. Clare.

The basaltic plateau of Counties Derry and Antrim

The upland plateau that forms most of Co. Antrim and three-quarters of eastern Co. Derry is made up of volcanic outpourings that settled out over the landscape in level sheets of lava as recently as 65 million years ago. This is, therefore, the newest part of Ireland. The northern edges of the plateau from Lough Foyle in the north to Belfast Lough in the east are scarped with some impressive cliffs. Where the basalt cooled slowly it split up into a series of vertically jointed polygonal columns which appear in their most dramatic form at the Giant’s Causeway.

Basalt rocks are composed of 45–55% silica and are classified as basic rocks. They also contain lime, and disintegrate through weathering to produce a comparatively fertile clayey soil, rich in calcium carbonate, providing an attractive environment for many arctic-alpine and alpine plants. Binevenagh, Co. Derry, in the northwestern part of the plateau, looks out over the flat and sandy coastline of Magilligan. Binevenagh has high and dramatic north-facing cliffs, standing over a jumbled, tortured mass of land slips, fallen rock and other debris. These cliffs are famous as one of the best locations in Northern Ireland for a wide range of arctic-alpine and alpine plants growing at uncharacteristically low levels. In fact, the interesting species reported here include two plants not found anywhere else in the province: purple saxifrage, growing sparingly between 275 and 330 m, and moss campion. The moss campion, noted here for its profuse growth and for having flowers that range in colour from deep purple to white (rare), is especially abundant around the screes above Bellarena and at the eastern end of the cliffs. Other species present are alpine scurvygrass (not seen recently³⁴), hoary whitlowgrass, mountain avens on the cliffs at 240–335 m, limestone bedstraw, dwarf willow and juniper.

Some 58 km further southeast on the high Garron plateau, sitting behind Garron Point on the Antrim coastline, there is an extensive tableland of bare and desolate blanket bog at an elevation of 305–366 m. The bog is deep and wet with many pools and small lakes. Growing here is the rare marsh saxifrage which has bright yellow, often red-spotted, flowers. It was formerly recorded from eight sites in Ireland, spread though six counties. Since 1970 it has only been recorded at this location, at three sites close together on the Nephin Beg Range, Co. Mayo, and at a mineral flush in the wet blanket bog near Bellacorick, Co. Mayo. It is also in decline in Britain.^16,35 On the Garron plateau it grows at a mineral flush, fed by a spring arising from the basalt rocks, and surrounded by the moss Drepanocladus revolvens. Other associated species are daisy, bogbean, selfheal, sharp-flowered rush, bog-sedge, glaucous sedge and large yellow sedge.

Garron Bog is also the home of two rare alpine sedges that grow at about 300 m in the area southeast from the Falls, in the upper Glenariff River to Trosk, high above the village of Carnlough. The few-flowered sedge occurs fairly commonly over a large area – at about 20 stations – extending over at least two 10 km squares of the national grid. It is a loosely tufted, creeping and mat-forming sedge with a shortish stem, up to 25 cm high and bluntly three-sided. The flowers are on a single bractless spike. First discovered by the Rev. H. W. Lett in 1889, this is one of only two Irish locations, the other being a watery peatland site on the edge of the Red Moss of Kilbroney, a somewhat miniature Garron plateau, at an altitude of 340 m on the Mourne Mountains behind Rostrevor, Co. Down.³⁴ The other sedge is the tall bog-sedge – first found by Miss Elinor D’Arcy in 1901 when she was only 11 years old – well-established on Garron Bog at several sites near pools, where it grows with Sphagnum moss and other sedges. Its leaves are 2–3 mm wide and its stems reach up to 40 cm. Until 1981 the Garron site was thought to be the only place where it grew in Ireland but then another location was discovered in an upland blanket bog in Co. Tyrone where it was growing on the west side of Lough Carn. It was later discovered in 1985 at Mill Lough, near Lough Fea and also at Lough Ouske, Co. Derry.³⁴

Sperrin Mountains, Co. Tyrone, manifesting erosion of the shallow peats.

Sperrin Mountains, Counties Tyrone and Derry

The Sperrin Mountains are made up of old rocks, mainly schists and gneisses in the northern parts, with Old Red Sandstone and a little limestone in the southern sections. The area is covered by upland blanket bog with a series of summits each rising to the region of 610 m. This is where the cloudberry was first found in 1826 by Edmund Murphy and Admiral Jones. It was growing in a single patch on a north-facing slope of wet blanket peatland at an altitude of about 533 m, west of the Dart Mountain summit. Today it flourishes almost submerged in the surrounding vegetation.³⁶ A member of the rose family, it is a small, blackberry-like plant with a white flower – a low, downy, creeping perennial spreading vegetatively by rhizomes. It is described as a ‘shy flowerer and fruiter’ in Ireland as it seldom, if ever, sets fruit. This is thought to be due to the overwhelming presence of plants of a single sex – the stamens (the male organ consisting of a filament and a pollen sac called the anther) usually set in a ring outside the flower centre, and styles (columns of filaments arising from the female organs terminating in the stigma receptive to pollen), usually located within the ring of anthers in the flower centre, are borne on separate flowers that are located in many separated single sex patches.

The Mourne Mountains, Co. Down

The Mourne Mountains stand up as a group of granite hills in south Co. Down with some flanking Silurian rocks. Carlingford Lough lies to the south. Many summits exceed 600 m, and the highest point is Slieve Donard at 850 m. Amongst the granite outcrops are some impressive cliffs and dramatic pinnacles that have originated by longer periods of weathering of the rock. Blanket bog covers the uplands and where the Silurian slates have been worn down by the weather, producing a richer soil, more interesting plants occur. The arctic-alpine and alpine flora is disappointing – already we are on the eastern coast of Ireland – and consists of the usual run-of-the-mill species. Amongst the plants of the higher ground, recorded by Praeger, are alpine saw-wort, dwarf willow, cowberry and alpine clubmoss. Lower altitudes host starry saxifrage, roseroot and the parsley fern. On the high cliffs of Slieve Bignian and Eagle Mountain Praeger recorded the very rare native form of the rosebay willowherb.³ It was still at the latter site in 1985 at an altitude of 455 m.³⁴ Also at the high altitudes are the brittle bladder-fern and the stag’s-horn clubmoss with its long and decorative ‘antlers’.

The Galty Mountains, Counties Tipperary and Limerick

The Galtys were thrust up during the dramatic Hercynian earth movements some 300 million years ago that were also responsible for creating the mountain ranges of the southwest of Ireland. This large crustal upfold has been worn down over millions of years. First the uppermost limestones were stripped off the summits, to survive only in the surrounding plains; next, the Old Red Sandstone was eroded along the crest to reveal the old Silurian rocks at the core of the upfold. Thus, the upper parts of the Galtys are made up of Silurian slates, shales and conglomerates to form a series of fine conical peaks that climax at 919 m on Galty Mountain. The bulk of the mountains rise above 762 m. The outstanding arctic plant of the Galtys is the northern rock-cress found at 293 m on a rock buff west of Lough Curra. This and the Glenade cliffs, Co. Leitrim are its only sites in Ireland. It rarely flowers on the Galtys. The best area for the mountain species, according to Praeger, are the cliffs over Lough Muskry.³ Investigating the area before him, the intrepid Hart found the arctic-alpines roseroot, starry saxifrage and mountain sorrel.³⁷

Mountain fauna

The fauna of Irish mountains and uplands contains very few surprises and, like the flora, is somewhat impoverished. None of the mountain ranges are high or extensive enough to provide the habitats for the true mountain species of birds such as are found in the Scottish Highlands – the ptarmigan, snow bunting and the dotterel. Even when it comes to invertebrates, especially the better investigated groups of butterflies and moths, the range of species is not one to go wild about. However, some interesting discoveries of relict arctic-alpine aquatic beetles have been made which might suggest that they survived the glacial phases of the Ice Age in some of the ice-free mountain summits. Here we will look more closely at the characteristic mammals, birds and invertebrates of mountain and upland areas.

Mammals

The largest living quadruped in Ireland is the red deer which is essentially a creature of the mountains and uplands. While there are several herds and scattered groups throughout the country, the deer in the Killarney Valley area, Co. Kerry, are probably the only ones with a claim to represent the native deer that roamed Ireland during the postglacial period. Once abundant throughout the country as a truly wild species, several herds managed to survive in the more remote areas of Erris, Co. Mayo, Connemara, Co. Galway, and in the Galty Mountains, Counties Tipperary and Limerick, until their extinction in the mid-nineteenth century (see here). Testimony of their once widespread distribution in Ireland is evidenced by the incorporation into numerous place names of the Irish word fiadh meaning ‘deer’. For example, Cluain-fhiadh, ‘the meadow of the deer’, is a parish in Co. Waterford, and Ceim-an-fhiaidh, ‘the pass of the deer’, marks the route taken by these animals when moving from valley to valley of the Lee and Ouvane areas in Co. Cork.

Two red deer hinds (F. Guinness).

The red deer living wild in the Wicklow Mountains and woods are the descendants of escapees from Lord Powerscourt’s demesne in the 1920s, although some authors date their liberation from the 1860s.³⁸ By the mid 1930s there were approximately 50 animals living wild in the Glencree and Glenmalur areas.³⁹ Numbers thereafter increased to about 250–300 animals during the war. Surveys in the early 1970s found only about 75 animals living in the open uplands, centred around the Mullaghcleevaun–Kippure (about 25 animals) and Glendalough–Glenmalur (about 50 animals) areas.³⁸ A further possible 30 were living in the woodlands near Glendalough to give a total population of approximately 105 for the Wicklow hills. Numbers since then have prospered because counts in June and August 1971 found a minimum of 168 and 187 respectively in the Wicklow upland area.⁴⁰

It is remarkable that there was no published systematic work on the diet of red deer in Ireland until 1993 when Sherlock & Fairley gave an account of the food of a small herd (a stag, five to seven hinds and calves) living in a 24 ha enclosure of open terrain, at Mweelin in the Connemara National Park, Co. Galway.⁴¹ The altitude ranged between 60 m to a maximum of about 120 m. The vegetation of the this area comprised 36% grassland/heath, dominated by heather and purple moor-grass; 35% peatland, dominated by purple moor-grass, common cottongrass, black bog-rush, bog asphodel and bog-myrtle; 16% grassland/bracken, dominated by bracken with the main grass being Yorkshire-fog and 13% grassland, comprised mainly of creeping bent, Yorkshire-fog, mat-grass, sheep’s fescue and sedges of the genus Carex. The food of the deer was determined by faecal analysis of 50 samples collected over one year. Grasses were the main food, forming at least 75% of the diet – primarily sheep’s fescue, creeping bent, sweet vernal-grass and Yorkshire-fog. The last three species were eaten most in summer and least in winter. Purple moor-grass, the dominant grass of the area, was only of importance in early summer when most palatable. Heather, the second most important food, was mainly eaten in winter. The diet of the Connemara red deer was comparable to that of the red deer living in the Scottish Highlands.

The goat is a frequent inhabitant of many Irish mountains. Here they are feral, having descended from domestic stock, either escaped or turned out by farmers mostly in the early part of this century. When in the wild for several generations, and sometimes within ten years, domestic goats revert to the wild or feral form. Those that have lived in the wild longest are shaggiest, wearing less patterned coats than their domesticated cousins. Despite the modern dairy goat weighing approximately twice that of the feral variety, there is no evidence to support a common assertion that feral goats represent a throw back to a wild type or ancestor of the modern goat. The degree of genetic purity of feral goats is considered high if there are no hornless adults and if none of the goats have small dangling tassels of hair on either side of their throats. Both these features are relatively recent characteristics of modern domesticated goats.

Many goats that were released into the wild have bred successfully to form small herds which have maintained and, in some cases, increased their numbers during the past hundred years. Feral goats are thought to live for about 12 years and weigh, on average, about 51–63 kg. They are browsers on vegetation, rather than grazers, and can cause damage to trees by stripping off the bark, especially during cold weather – ash, elm, yew, rowan, holly and hazel are favourite species to nibble. Lever remarks that approximately 20 goats living on the cliffs of Rathlin Island, Co. Antrim, are possibly the descendants of some liberated in about 1760, while those on Achill Island, Co. Mayo, also date from about the mid-eighteenth century.⁴² In the Mullagh More area of the Burren, Co. Clare, a lowland herd of approximately 60–70 feral together with domestic goats wander and feed off the limestone pavement and in hazel scrubland. They move around in sub-groups with considerable interchange of individuals between the different herds. They also welcome more domesticated beasts in their midst, thus demonstrating the openness of the feral gene pool to new blood. Rutting starts about mid-September, intensifies in October, and is over by the end of December. The first kids are born five months after mating. A feature of the Burren goats is the unusually high survival rate of kids. The availability and high nutritional status of the food supplied by the karst environment – despite appearing rather impoverished to the layman – probably accounts for such healthy results.⁴³

Feral goat.

The goat in Ireland is celebrated as the central figure in the ‘Puck Fair’, a ceremony dating back to at least 1613. A male goat is first crowned as Tuck King of the Fair’ and then ‘His Majesty Puck King of Ireland’. According to Murray, quoted by Whitehead,⁴⁴ the name Puck is a derivative from the Slavonic word bog, which means God.

The Irish hare, once considered to be a separate species until a critical examination demoted it to the rank of a subspecies Lepus timidus hibernicus of the mountain hare, occurs only infrequently and at very low densities on Irish mountains. When disturbed from its ‘form’ or day resting place on the hillside, it takes off madly, sometimes pausing upright on its hind legs to examine the intruder, to another distant destination on the mountain. In northwest and west Scotland these mountain hares frequent the arctic and alpine zones of the high summits, sheltering there amongst the boulders. Further south in northern England, in the Peak District mountains, the species is generally confined to the heather and cottongrass in vegetation zones that are found between 300 and 550 m above sea level. On the Isle of Man, a sort of halfway house to Ireland, they are restricted to a generally lower altitude, between 153 and 533 m. In Ireland the hares seem happiest on even lower mixed farmland habitats. Here they have little or no competition from the brown hare, normally absent from these parts. On the lowland Irish farmlands the mountain hares reach densities of up to ten times higher than recorded on lowland moorland bogs – a response to better feeding conditions and shelter.⁴⁵

Birds

At the Annacoona cliffs in the Gleniff Valley, Co. Sligo, numerous ravens populate the air above the escarpments. One unusual species here, however, nearly 10 km from the sea, is the chough, rarely found breeding so far inland. The 1982 national chough survey showed that three-quarters of all inland breeding sites were found within 8 km from the sea; the site furthest out was 19 km away in Macgillycuddy’s Reeks, Co. Kerry.⁴⁶ The Gleniff choughs are therefore quite remarkable. Another unusual bird around the cliffs, noted in the summer of 1996, was the mistle thrush, a species unknown in Ireland before 1800 when the first one was shot in Co. Antrim. Soon afterwards it bred for the first time in Co. Down and since then the thrush has been on the increase and has colonised almost the whole of Ireland. Not normally associated with bare and naked landscapes, the Gleniff birds were probably breeding in the wych elm or rock whitebeam trees that seem to sprout out of the cliff faces. However, mistle thrushes have also been known to nest on rocks.⁴⁷

The ring ouzel, a summer visitor from northwest Africa and the Mediterranean, is the only bird confined to the higher and wilder mountain areas of Ireland. This is a somewhat mysterious thrush, not well known to Irish naturalists. Prior to 1900 it bred in all counties except Meath, Westmeath, Longford and Armagh,⁴⁸ but breeding numbers have declined this century to an estimated population of only about 270 pairs, found principally in the Wicklow Mountains, the Mourne Mountains, Co. Down, the mountains of north and west Donegal, and the Kerry mountains – where they may have been increasing in recent years. They are also reputed to be in the mountains of south Connemara although Whilde writes that they have not been reported nesting there for many decades.⁴⁹ The male is as black as the male blackbird but it has a white bib; the female, brown like her counterpart, has an off-white bib.

Although several historical records of breeding at sea level exist, the ring ouzel seldom nests below 300 m. Steep-sided valleys and ravines are favoured habitats with most nests placed on rock outcrops or ledges. Abandoned buildings and walls will sometimes be used, as well as dense bracken or heather. Little is known about the ecology of the ring ouzel in Ireland. Some basic studies would be most valuable.

Eight other birds could be said to be characteristic but not dependent upon mountain and upland areas. These are, in descending order from the summit: peregrine falcon, raven, hooded crow, hen harrier, meadow pipit, merlin, red grouse and the golden plover. Both the red grouse and golden plover also occur on lowland blanket bogs and they are discussed in Chapter 4.

The peregrine and raven inhabit all the major inland and coastal mountain systems where there are suitable cliffs for nesting. They are equally at home in coastal cliff habitats. Both are widespread throughout the country. The numbers of breeding peregrines in the Republic prior to 1950 was estimated rather uncertainly at some 180–200 pairs. A dramatic population decline, similar to that experienced in Britain, followed during the 1950s and 1960s. Possibly as few as 14 pairs were thought to have been successfully breeding in Ireland by 1970.⁵⁰ This was due to the presence in the countryside of seeds dressed with organochlorine chemicals to prevent insect attack on crops. These were eaten by the woodpigeon, stock dove and rock dove which in turn were preyed on by peregrines which accumulated in their bodies an ever increasing load of the persistent chemicals. If not directly killed by the poison, sub-lethal levels interfered with the metabolism of calcium, affecting its deposition in egg shells. The resultant thin shells led to a high incidence of egg breakages, and elevated residue levels in the embryos brought about a decline in breeding success. Without enough young birds recruited, the population went into serious decline. It was only when the chemicals were withdrawn that the population began to recover. In 1981 all Northern Ireland and approximately 50% by area of the known breeding range in the Republic were surveyed and at least 278 breeding pairs noted.⁵¹ Today there are probably over 500 breeding pairs throughout the whole island. Numbers are still increasing with most of the old traditional breeding sites once again occupied while new sites are being established. Quarry-nesting peregrines, first noted in the late 1970s, are on the increase. A survey of 48 quarries, active and disused, in nine counties of eastern Ireland in 1991 and 1992 revealed 21 breeding pairs. If this occupancy rate was extended to all the 300 quarries in the Republic then there may be up to approximately 130 breeding pairs of peregrines in this somewhat unusual habitat.⁵² In 1977 some 35 pairs bred in Northern Ireland quarries.

Comeragh Mountains, Co. Waterford, where ring ouzels breed.

In 1986 Noonan carried out a study of peregrines breeding in 2,025 km² of Co. Wicklow and found 34 territories, or one pair per 60 km².⁵³ The 12 successful eyries produced 2.4 fledged chicks per nest. This figure compared with 2.17 fledged chicks from a longer-term study in five southeastern counties in Ireland over the period from 1981–6. However, when these results were expressed as the mean number of chicks fledged per pair of peregrine holding a territory the figure was only 0.91 chicks. It was also found that breeding performance at coastal, compared with inland, sites was higher with 0.95 and 0.78 chicks respectively produced per pair of peregrines holding territory.⁵⁴

Ravens are more numerous than peregrines in Ireland with an estimated population of 3,500 breeding pairs in 1988–91.⁵⁵ However, this would appear to have been a gross over-estimate, and the true breeding population is more likely to be in the order of 1,000 pairs, divided between mountain, upland and coastal habitats.⁵⁶ Their shared interests in sometimes similar habitats with peregrines can lead to spectacular aerial encounters. But how do two large and extremely agile birds get along together when they require similar breeding sites? The mechanism for apportioning out available cliffs is not clear but may well be based on precedent of who got there first. If either occupant moved off, for whatever reason, or died, the site would be up for grabs. Their mutual respect for each other has been witnessed and filmed by the author in aerial encounters during which a peregrine will playfully stoop on a raven that will suddenly flip over on its back and point its massive claws upwards, without actually grappling with the peregrine.

Historically ravens were relentlessly persecuted by man because they were perceived as predators of young lambs and sickly sheep, and by 1900 only a few pairs survived in a small number of remote coastal areas. With the relaxation of this murdering grip at the beginning of this century, a remarkable population increase commenced which has led to the species unfurling into virtually all the hills and mountain areas of the country. In a study of ravens in Co. Wicklow during 1968–72 a population density of one breeding pair per 25.3 km² was found, close to the one pair per 23.9 km² recorded in north Wales moorland for enclosed sheep farms. In both Wicklow and Wales the raven occupied generally similar habitats.⁵³ Highest densities are in the western uplands where the greater sheep numbers provide the attendant supplies of carrion – the amounts of which were indicated by a study on the blanket peatlands around Glenamoy, in west Mayo, during the early 1970s. The stocking levels on these bogs at that time was roughly one ewe per ha, and losses between October and April were estimated at about 7–10% of total numbers. On average about 1.0–1.4 carcasses per km² per month became available to the predators. It was also found that carcasses weighing 30–35 kg disappeared in less than two weeks, indicating the intensity of scavenging by ravens, hooded crows and foxes.⁵⁷

The hooded crow is more a bird of the uplands but, like the peregrine and raven, it has an interest in other habitats, as evidenced by the large population in Ireland, estimated at about 290,000 pairs. The success of the species is a reflection of their ability to adapt to all available food sources. A constant feature of the mountains and uplands, hooded crows move around singly or in pairs, always on the scrounge for sheep carrion or nests of other breeding birds that are quickly plundered. In the mountains and uplands they generally build their nests in low, often isolated trees but will also resort to cliffs and low bushes. Essentially carrion feeders, they have done well in recent years, seldom short of a dead lamb or ewe whose carcasses have increased proportionately with higher stocking densities. During the winter hooded crows often come together in large roosts: close to 170 individuals were counted in one flock at Youghal, Co. Cork on St Patrick’s Day in 1978. As a subspecies of the all black crow, hooded crows will interbreed with the black carrion crow and produce fertile offspring. However, the opportunity for matrimony is not great in Ireland as the carrion crow is scarce, and found principally in the northeast of Ireland – although it has been creeping down southwards towards Dublin in recent years.

The hen harrier is most likely to be seen quartering moorland below 500 m, especially in areas covered by young forestry plantations which, in their early stages of development, offer excellent breeding habitat for the species. A dense growth of tall vegetation such as heather is also suitable nesting habitat. Formerly widespread throughout Ireland, these docile-looking birds were persecuted by gamekeepers to the point of extermination in the second half of the nineteenth century and were thought to have become extinct in 1954. Fortunately a few pairs were lurking in the Slieve Bloom Mountains, Co. Laois, and on the Waterford/Tipperary border. Numbers picked up dramatically as large areas of amenable breeding habitat became available to the species through a reinvigorated State afforestation programme. By 1973–5 there were 250–300 breeding pairs on the Irish uplands.⁵⁸ Since then, however, they have declined again, dropping to probably fewer than 100 pairs. Reasons advanced for this reversal relate to maturing forestry plantations together with the clearance and reclamation of marginal uplands, representing a loss of breeding and hunting habitat for the species.⁵⁹ However, this explanation is not entirely satisfactory as afforestation is not a thing of the past and new plantations, providing renewed attractive habitat, are still being created all around the country. Today most of the estimated 60–80 pairs are located in the uplands of Kerry, Limerick, Cork, Clare, Tipperary and Laois.⁶⁰ Some also breed in Tyrone, Fermanagh and Antrim. Recent sightings in Galway and Mayo may relate to breeding birds. Hen harriers have also decreased in England and Wales but appear to have remained stable in Scotland. Recent estimates for the population breeding in western Europe, excluding Ireland and Britain, gave 4,160–6,610 pairs.⁶¹

Hooded crow. Widespread throughout Ireland. (F. Guinness).

The buzzard, a common breeding bird on inland cliffs and in woodlands in Donegal, Derry, Antrim and Down during the nineteenth century, was persecuted by shooting and poisoning until it became extinct shortly before the turn of the century. At the same time buzzards remained widespread in the western upland areas of Britain. Following several attempts earlier this century to reestablish themselves in Antrim they finally managed reinstatement there in the early 1960s. Since then they have spread to all six Northern counties with an estimated population of 120 pairs in 1991. The population has also spread out of the North into adjoining counties and southwards into the Republic where the population rose from one known pair in 1977–9 to 26 pairs reported 1989–91. Most were in Donegal (13 pairs) followed by Monaghan (7 pairs), Wicklow (3 pairs), Louth (2 pairs) and Cavan (1 pair).⁶² Their recolonisation has been facilitated by a more enlightened attitude by game keepers and farmers and a reduction in the amount of poison laid to protect lambs from corvids and foxes. Moreover the use of strychnine was banned in the Republic in 1992 in conjunction with an attempt to reintroduce the white-tailed sea eagle to the Dingle Peninsula area.

The kestrel, despite possibly being the commonest bird of prey in Ireland, occurs at lower densities than encountered in most other European countries, the reasons for which are not entirely clear.

The passerines, apart from the ring ouzel, characteristic but not dependent upon the mountains and uplands include the ubiquitous meadow pipit, whose small size and nondescript streaky brown plumage belie its tenacity for survival in a hostile environment. With an Irish breeding population estimated at over a million pairs there are plenty to spread around in all Irish habitats ranging from farmland, rough grasslands, young forestry plantations, peatlands and mountains and uplands where, above the altitudes of 500 m, it is the commonest nesting bird. Managing to find enough invertebrates, particularly flies (including mosquitoes) populating grassy and heathery slopes, the pipit, in turn, is the principal food item for the merlin as well as main host-cum-victim to wandering cuckoos. In recent years a decline in the numbers of meadow pipits breeding in southeastern and eastern Ireland has been noted – probably a consequence of the agricultural improvement of marginal lands. Today its strongholds are in the western and northwestern counties.

Merlins are equally at home in lowland blanket bogs as they are in the mountains and uplands. The estimated size of the Irish breeding population is 200–300 pairs, concentrated mainly in the uplands of Wicklow, Galway, Mayo and Donegal. They also occur in the uplands in Northern Ireland. A special survey carried out in 1985 by Haworth in the great expanse of lowland blanket bog between Errisbeg and Clifden in west Galway revealed the presence of 12 pairs, eleven of which were breeding on wooded islands in small lakes, the other in a coniferous plantation. Eight nests were successful in their breeding outcome and 32 merlins fledged.⁶³ In the uplands of Wicklow merlins breed in coniferous plantations while in Northern Ireland they often settle in the abandoned nests of hooded crows. A study by Toal in Derry, Tyrone and Antrim found that of 22 recorded nests 19 had previously been taken over from hooded crows in trees and only two were on the ground. All nesting took place above 150 m and most sites were either in sitka spruce plantations, or on the edge of them.⁶³

Other birds frequently occurring but not in any particular way tied to these regions are the wheatear which likes open spaces strewn with landmarks such as boulders under which they can nest or in hollows in turf banks, and wren, also able to exploit opportunities in seemingly barren areas. Another bird, not well known and whose ways, like those of the ring ouzel, are somewhat mysterious, is the twite, a small brown finch. It is found in the remote western coastal areas from Donegal to Kerry, but also in some mountain and upland regions where it nests in heather or low bushes. Some 750–1,000 pairs are estimated to breed in Ireland and the population is thought to be declining.⁶⁰ Both the twite and the ring ouzel offer plenty of scope for study by naturalists.

Invertebrates

The coldness and harsh climate of the mountains and uplands have restricted the number of invertebrate species in these habitats and most attention has been paid by naturalists to the more spectacular butterflies and beetles. The only butterfly confined to the mountains and uplands is one of the hardiest of them all, the small mountain ringlet, which in Europe is seldom found below an altitude of 460 m. In Britain, when it occurs, it is usually between 200 and 900 m. Adults are a drab, sooty brown with a band of black spots fringing the margins of their outer wings, each surrounded by a lighter tawny zone. Its caterpillars are grass-green and feed on mat-grass. There are only four known specimens from Ireland, all preserved in the scientific collections of the Natural History Museum, Dublin, and the Ulster Museum, Belfast. One was from ‘a grassy hollow about half way up the Westport side of Croagh Patrick,’ Co. Mayo, June 1854; the second from the hilly slopes on the eastern shores of Lough Gill, Co. Sligo in 1895 and the third from Nephin Mountain, Co. Mayo in 1901. The fourth specimen is just labelled ‘Irish 30.6.18.’ Almost every year entomologists try in vain to rediscover this elusive prize but despite repeated searching it fails to be turned up, thus leading to the conclusion that it is probably now extinct. One difficulty in recording its presence is that it flies only in sunshine, spending the rest of its time lurking in damp mountain and upland grasses. If it still exists in Ireland it is most likely to be found in the Nephin Beg area, Co. Mayo, which is considered to offer the best habitat opportunities.⁶⁴

The large heath, another upland inhabitant, has been recorded up to 365 m at the Windy Gap, Co. Kerry. Unlike the mountain ringlet it is not confined to mountain and upland areas, with many occurring on the lower blanket and raised bogs. The adults are on the wing for only a short time in the summer – from the middle of June to the end of July. The caterpillar is about 2.5 cm long, grass-green in colour, striped by dark green on its dorsal surface and white along the sides. It is thought that common cottongrass and purple moor-grass are probably important food for the caterpillars, as well as white beak-sedge when it is available. The large heath is a very variable species as regards its colouring and wing markings. There are several subspecies, with two recognised in Ireland – Coenonympha tullia scotica and C. t. polydama. The former is confined mainly to the south and western Ireland.⁶⁵ The latter occurs in many parts of the country but its main stronghold appears to be in the Midlands and in the north of Ireland.⁶⁶

The emperor moth, easily identified by its prominent eyespots on the upper and lower wing surfaces, is on the wing from April to end June especially on upland boglands. Another moth, the beautiful yellow underwing, takes it name from the yellow central area, bordered by black, on the underwings. Both these moths may be encountered on Irish uplands and mountains together with numerous other smaller, paler moths exploding upwards for a brief dashing flight when disturbed by a hill walker or roaming beast before plunging back down into the protective vegetation.

In contrast to the highly mobile butterflies and moths, many other invertebrates are yoked to their local environments. One interesting group is the water beetles belonging to the family Dytiscidae which, although most are well able to fly, tend to remain confined to very specific aquatic habitats, especially within the mountainous environment. These water beetles have evolved adaptive devices to make their aquatic lifestyle easier – their heads are generally sunk into the thorax and the body is smooth and rounded, both facilitating their passage through water. They also possess broad hind legs, flat and fringed with hairs to act as efficient paddles. Although rising to the surface, tail first, to renew the oxygen supply is still necessary, the water beetles can also hibernate, particularly in order to overcome cold conditions. Both the adults and larvae are aggressive carnivores. Some larvae reach up to 6 cm long and will successfully tackle small fish and even take on, working with their fierce looking hard jaws, a tasty-looking finger of a hapless bug hunter. Several members of the Dytiscidae found in Ireland have been identified as glacial relicts that ‘chilled out’ in their mountain-top pools as the ice sheets were banging around in the valleys below.

A particularly rich site for these relict species is the top of Doughruagh Mountain (526 m), a northern outlier of the Twelve Bens of Connemara, west Galway. Several small, shallow pools pepper the summit. The vegetation is meagre and includes bog pondweed, water lobelia, water-milfoil, Myriophyllum sp., bulbous rush and the sub-aquatic moss Scorpidium scorpioides. These often mist-shrouded and rain-drenched pools are the unlikely spots, because of their barren mountain summit locations, for spawning frogs. The ensuing tadpoles enter into the diet of the rapacious larvae of two very rare Dytiscidae found here: the alpine and smallest of the great diving beetles Dytiscus lapponicus and an arctic-alpine species Agabus arcticus. The nymph of another glacial relict, the water boatman Glaenocorisa propinqua, has also been recorded here⁶⁷ as well as on the Peakeen Mountain, Co. Kerry and in the Blue Stack Mountains, Co. Donegal. It has also been recorded from Lough Nacartan (30–60 m above sea level), Killarney, Co. Kerry, and in Upper Lough Bray (425–457 m above sea level).⁶⁸ The only other Irish records of Dytiscus lapponicus are from Co. Donegal, the Partry Mountains, west Mayo and Co. Kerry. As for Agabus arcticus, it has been found in pools in the Wicklow Mountains and from Glenariff and Lough Evish in Co. Antrim. The adults in the population of the glacial relict stonefly Capnia atra living in the Devil’s Punch Bowl (over 700 m above sea level) near the summit of Mangerton Mountain, Co. Kerry, are brachypterous – short winged and non-flying – considered to be a selective advantage as because they cannot fly they are prevented from being blown away to an unsuitable area in such a windswept region.⁶⁹ Another insect survivor from the Ice Age is a small alpine caddisfly Tinodes dives,