The Orkney vole is a sub-species of the common vole and unique to the Orkney Islands. It is larger and heavier than the common vole. It is bigger than a mouse, with a rounded head and a relatively short tail.

Behaviour

Orkney voles do not hibernate. The vole is the islands’ only rodent to be active during the day and is an important food source for hen harriers and short-eared owls. The diet of the Orkney vole consists largely of plant materials, seeds and cereal crops. Females can have several litters a year, each with 3-6 young. The young are fed by the mother for about 20 days, when they then switch from milk to normal feeding.

Size

• Length: 9 – 12cm (tail length approximately one third of body length)
• Average weight: 30g; up to 90g
• Lifespan: 18 months

Status

Although once common, it is thought that the Orkney vole population has declined substantially over the past 50 years. This is linked to changes in agriculture, with the drainage of rough grassland and conversion to improved grasslands for livestock. More recently, their lives are threatened by stoats, which were first sighted in Orkney in 2010.

Distribution

Orkney voles are present on eight of the Orkney Islands. Formerly widespread, even in agricultural crops, Orkney voles are today confined to semi-natural habitats with maximum densities occurring in old peat cuttings and rough grassland.

When to see

January to December. It is active throughout the year, but is not so apparent in winter when it spends more time underground.

Facts

• The Orkney vole has an enigmatic history. Its closest relative is the common vole which is found throughout Europe, but intriguingly not on the UK mainland or Ireland. Following numerous studies and theories, it required cutting edge DNA techniques to throw a definitive light on its origin. The most recent analysis of nuclear DNA suggests the closest match is with an archaeological specimen in Belgium.
• The vole’s mode of arrival to Orkney is hotly debated. Genetic research has revealed that there is a large genetic diversity in both modern and ancient Orkney voles. This suggests that they arrived with humans, (deliberately or as unintended stowaways) around the Neolithic period when the first farmers settled on Orkney. Copious vole remains have been found in excavations of tombs and houses from that time.
• The oldest known radiocarbon-dated fossil of the species in Orkney is 4,600 years old.
• Locally, Orkney voles are also known as volo, cutticks, or cutoo.