There appears to have been a sea channel between the Outer Hebrides and the mainland throughout the last glaciation. If so, all the mammals on the islands today, both domestic and wild, must have been carried there by man. Records from the late seventeenth century and present day (tab. 1) show that the fauna is very restricted. Archaeological records also show few species (tab. 2). Larger wild mammals were presumably introduced for products such as fur and antler and as fall-backfood supplies, while the micromammals were carried unintentionally. Boats have been used for transport of stock from the lime of Neolithic colonisation, and continue to be used for routine movement of stock to summer grazing grounds, to deserted is-lets to establish feral flocks, and to carry animals beyond the islands as part of the exchange net-work and commercial trade.