Researcher Tim Healing and assistants catching voles in 1989.

The Skomer vole is a sub species of bank vole that is endemic to Skomer, it is one of four small mammals on the island, including the wood mouse, common shrew and the pygmy shrew. It was thought that the bank vole was introduced to the island by accident possibly by a boat, and they have been on the island for so long that they have become genetically different to the mainland bank vole, creating a new subspecies. The Skomer vole is larger and has slightly different behaviour to the mainland bank vole; they are not used to having any ground predators and so are quite tame.
They are only used to aerial predators and so stay still when they feel threatened.