The Castlepook Reindeer Question
Ireland had not yet reached the Last Glacial Maximum, the later phase when a greatly enlarged British–Irish Ice Sheet covered much of the island and reshaped its terrain. The best current reconstructions describe the ice sheet as building between about 31,000 and 26,000 years ago, before its maximum extent and volume in the following millennia. Around the period represented by 31,876 BCE, conditions were cold and unstable, but the available evidence indicates that at least some areas of Ireland remained ice-free. This was not a green, familiar island waiting to be settled. It was a high-latitude landscape repeatedly affected by severe climatic shifts, frost action, sparse vegetation and the approach of expanding ice.