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