The Orkney vole is a population of the common vole

Common Vole

The Common Vole, Microtus arvalis, is a European mammal.- Distribution and habitat :The common vole is hardly restricted in means of distribution and habitat and inhabits large areas of Eurasia. As Microtus arvalis followed human civilisation, primary and secondary habitats can be distinguished...

 (Microtus arvalis) found in the Orkney Islands

Orkney Islands

Orkney also known as the Orkney Islands , is an archipelago in northern Scotland, situated north of the coast of Caithness...

, off the northern coast of Scotland

Scotland

Scotland is a country that is part of the United Kingdom. Occupying the northern third of the island of Great Britain, it shares a border with England to the south and is bounded by the North Sea to the east, the Atlantic Ocean to the north and west, and the North Channel and Irish Sea to the...

, United Kingdom

United Kingdom

The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

. Orkney voles are larger than voles from other populations of the common vole. The common vole does not occur elsewhere in the British Isles

British Isles

The British Isles are a group of islands off the northwest coast of continental Europe that include the islands of Great Britain and Ireland and over six thousand smaller isles. There are two sovereign states located on the islands: the United Kingdom of Great Britain and Northern Ireland and...

.

The Orkney vole occurs on five islands:

• Mainland
• Sanday
  Sanday, Orkney
  Sanday is one of the inhabited islands in the Orkney Islands, off the north coast of Scotland. With an area of , it is the third largest of the Orkney Islands. The main centres of population are Lady Village and Kettletoft. Sanday can be reached by Orkney Ferries or plane from Kirkwall on the...
  
  
• Westray
  Westray
  Westray is one of the Orkney Islands in Scotland, with a population of around 550 people. Its main village is Pierowall, with a heritage centre, the ruined Lady Kirk and ferries to Papa Westray.-Geography and geology:...
  
  
• Rousay
  Rousay
  Rousay is a small, hilly island about north of Orkney's Mainland, off the north coast of Scotland, and has been nicknamed "the Egypt of the north", due to its tremendous archaeological diversity and importance....
  
  
• South Ronaldsay
  South Ronaldsay
  South Ronaldsay is one of the Orkney Islands off the north coast of Scotland. It is linked to the Orkney Mainland by the Churchill Barriers, running via Burray, Glimps Holm and Lamb Holm.-Geography and geology:...
  
  

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. However, others do not recognise any subspecies of the common vole.

Orkney voles do not occur in mainland Britain

Great Britain

Great Britain or Britain is an island situated to the northwest of Continental Europe. It is the ninth largest island in the world, and the largest European island, as well as the largest of the British Isles...

, nor elsewhere in the British Isles

British Isles

The British Isles are a group of islands off the northwest coast of continental Europe that include the islands of Great Britain and Ireland and over six thousand smaller isles. There are two sovereign states located on the islands: the United Kingdom of Great Britain and Northern Ireland and...

, and they are thought to have been introduced to the Orkney archipelago

Archipelago

An archipelago , sometimes called an island group, is a chain or cluster of islands. The word archipelago is derived from the Greek ἄρχι- – arkhi- and πέλαγος – pélagos through the Italian arcipelago...

 by humans in Neolithic

Neolithic

The Neolithic Age, Era, or Period, or New Stone Age, was a period in the development of human technology, beginning about 9500 BC in some parts of the Middle East, and later in other parts of the world. It is traditionally considered as the last part of the Stone Age...

 times. The oldest known radiocarbon-dated

Carbon-14

Carbon-14, 14C, or radiocarbon, is a radioactive isotope of carbon with a nucleus containing 6 protons and 8 neutrons. Its presence in organic materials is the basis of the radiocarbon dating method pioneered by Willard Libby and colleagues , to date archaeological, geological, and hydrogeological...

 fossil of Common Vole in Orkney is 4,600 years old: this marks the latest possible date of introduction. The likely source areas for Orkney voles are what is now France

France

The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

 or Spain

Spain

Spain , officially the Kingdom of Spain languages]] under the European Charter for Regional or Minority Languages. In each of these, Spain's official name is as follows:;;;;;;), is a country and member state of the European Union located in southwestern Europe on the Iberian Peninsula...

.