 The common vole is absent from the rest of the British Isles.The Orkney vole occurs on eight islands of the group, Mainland, Sanday, Westray, Rousay, South Ronaldsay, Burray, Eday and Stronsay.In the past the populations on each of these islands have been named as subspecies, and the Orkney vole as a whole is considered by some taxonomists to be a subspecies of the common vole because of its size difference from the common vole.