The Midlandian cold stage as described above was not as severe as the Munsterian cold stage. It is named after the elongated ice dome that was located between Galway City and Castlerea, Co. Roscommon, which sent ice sheets southwards through the Midlands which petered out along a line from Kilrush in the Shannon estuary to Tipperary town and then northeastwards to the Wicklow hills. There were also local ice caps to the mountains together with valley glaciers in Donegal, Wicklow, Cork and Kerry. Temperatures in the ice-free zones were possibly similar to cold Continental conditions, approximating parts of Siberia today. The landscape, out of reach from the glaciers, was probably open grassland with scattered woods of dwarf birch and least willow with only small amounts of bare tundra.2 It was in this environment that many of the prehistoric animals existed.
The earliest known remains of animal bones in Ireland come from the east shore of Lough Neagh at Aghnadarragh, near the village of Glenavy, where lignite deposits date from about 55,000 years ago. A number of teeth and bones of the woolly mammoth together with bones of the musk ox were found in the thin glacial covering sitting on top of the lignite and probably dating from over 50,000 years ago.27 The bones of bison have also been reported at this site but may be the result of misidentification – bison are close relatives of the musk ox.2 Plant and beetle fossils from the area suggest temperatures very similar to those of today, giving the period the characteristics of a warm interstadial. Two tree species – yew and hazel – grew in scattered woodlands. During this period it is likely but not proven by the discovery of bone remains that there were other large mammals in the Irish countryside such as Irish giant deer, reindeer, brown bear and spotted hyena. Some of these were to become extinct with the resurgence of ice during the Drumlin phase of the Midlandian cold stage (35,000–13,000 years ago).
The Drumlin phase opened as cool interstadial with massive ice developing later and peaking at 25,000 years ago.2 As the temperatures nose-dived, many animals took refuge in nearby caves where their bones lay dormant until discovered by the cave explorers. Ussher’s, Praeger’s and Scharff’s findings included woolly mammoth, red deer, giant Irish deer, reindeer, brown bear, wild boar, mountain hare, Arctic fox, spotted hyena, Norway lemming and Arctic or Greenland lemming.
Interpretation of the historical sequence and associations of the species was beset by problems of shifting soil horizons due to water movements in the caves, much of which was caused by melting ice from the glaciers. Additional problems were created by badgers entering the caves much later, and disturbing the bones embedded in the soil when excavating their setts. There were also cases of collapsing ceilings bringing in intruders from the strata above the caves. Radiocarbon dating was not available to Praeger, Ussher and Scharff at the beginning of the century, hence the difficulty of disentangling the muddle of bones. It is only very recently, in last 25 years, that cave explorers have been able to place their finds accurately within a chronology.
In 1993 a selection of some 30 samples of known bones, recovered from caves by early investigators and entrusted to the quiet security of museums, had small extracts of collagen removed for radiocarbon dating at the Oxford University Accelerator Unit. The programme was devised by Woodman & Monaghan.27 The project had three aims: to discover (i) which mammals were in Ireland before the final glaciers of the Midlandian cold stage; (ii) which animals were present afterwards in the late glacial period and (iii) which were present in the postglacial period from some 10,000 years ago.
The radiocarbon results (given as median dates in years ago and rounded to the nearest 100), based on bones from Castlepook and Foley’s caves in Co. Cork and Shandon cave, Co. Waterford, showed that in the ice-free zones in Cork and Waterford giant Irish deer (32,100), reindeer (28,000), Norway lemming (27,900), woolly mammoth (27,200), brown bear (26,300), red deer (26,100) Arctic lemming (20,300) and Arctic fox (20,000) were present. During the late glacial period the following species were found in caves in Cork, Sligo, Clare and Limerick: reindeer (12,500 and 10,900), brown bear, (11,900 and 10,700), red deer (11,800), giant Irish deer (11,800), wolf (11,200) and Arctic lemming (10,000), showing that the first four species soldiered on into the late glacial period (13,000–10,000 years ago). The gradual warming up of the landscape was rudely interrupted by the Nahanagan stadial, during which the mean annual summer temperatures may have been less than 5°C. Many questions remain as to the impact of this sudden temperature reversal on flora and fauna. However, it should be remembered that Arctic foxes, Greenland lemmings, Arctic hares, ermines, wolves and musk ox as well as hundreds of insect and flowering plant species are able to survive Greenland winters when temperature drop as low as -20°C with summer temperatures higher than experienced during the Nahanagan stadial. The question applies to all the previous cold periods. If some animals and plants were able to survive the Drumlin phase of the Midlandian and subsequent Nahanagan stadial then the need to argue for their land bridge arrival in Ireland is considerably weakened. Many of the large herbivores disappeared, together with their carnivore predators, with the decline of their important grasslands.
Without further information from a large scale radiocarbon dating programme it will remain a moot point whether the known early mammals such as Arctic hares, red deer and wolf, and species such as stoats, otters, pine martens, etc., for which there is no evidence yet of their early occupancy, achieved a continuous presence in Ireland through to the postglacial period, when a warmer and a more environmentally friendly landscape re-emerged, or whether they re-entered Ireland as immigrants across the land bridge. All that can be said is that Woodman & Monaghan dated red deer bones from 4,200 years ago at Stonestown, Co. Westmeath and to 2,020 years ago at Sydenham, Co. Down and that brown bears were present in Ireland as recently as 8,900 years ago – as testified by remains at Derrykeel Bog, Co. Offaly. They were contemporary with the first human settlers at Mount Sandel on the lower reaches of the River Bann, just south of Coleraine, Co. Derry.
Animal bones recovered from County Clare caves. 1–5 Crane bones; 6 Hawfinch? 7 Arctic fox; 8 Domestic cat; 9 Irish wild cat. From Scharff et. al.26
Lynch & Hayden have argued that the range contraction of the Arctic hare and stoat, both present in the Castlepook interstadial (35,000 years ago28), before the Drumlin phase of the Midlandian period, into an ice-free southern Co. Cork, together with their genetic isolation from their assumed British and Continental mother stock, may have been sufficient time for both the stoat and hare to develop their subspecific characteristics.29 They tested morphological differences by multivariate analysis of cranial measurements between Irish, English and Scottish carnivores – badger, mink, otter and stoat. Significant differences between English, Scottish and Irish badgers, otters, mink and stoat populations were demonstrated – the greatest were between the Irish stoat and its English counterpart, thus strengthening the argument for the stoat being a glacial relict species. Little evidence was found for musteline colonisation of Ireland via a land bridge between northeast Ireland and Scotland. The evolution of established subspecific differences which separate Irish hares and otters from their English relations would also have been facilitated by their genetic isolation provided by their presence in Ireland some 35,000 years ago.
Woodman & Monaghan also attempted to unravel the history of the horse in Ireland.27 Was it introduced around 4,000 years ago or was it a survivor, in its wild form, from the late glacial to the postglacial period – as is the