Today, we have a fascinating guest post from Ann Cockerton, who until recently was the Orkney Native Wildlife Project communications manager.

Our annual wildlife monitoring surveys concluded last month with the completion of the Orkney vole surveys. The Orkney vole is a genetically distinct sub-species of vole found only in Orkney. It is notably larger than its mainland counterpart, weighing in around a chunky 90g, and is thought to be descended from voles found in Belgium.

How they arrived in Orkney isn’t known, but there are plenty of theories and they possibly arrived with Neolithic travellers migrating between Europe and Orkney 3,000 BC either accidentally carried in the livestock bedding or deliberately. There is speculation that voles were brought as food, like the Romans using edible dormice on sea journeys. This is supported by analysis of Orkney vole remains from Skara Brae, which indicates they were used as a food source in Neolithic Orkney.

Professor Mark Edmonds in his book Orcadia: Land, Sea and Stone in Neolithic Orkney suggests that voles were arriving around the same time as people gathered among the monuments of the Brodgar 5,000 years ago. Among the animal remains found at Skara Brae over the years are hundreds of bones from the Orkney vole.

During those millennia that the Orkney vole naturalised here, it became an important food source for native wildlife, especially short-eared owls and hen harriers during the breeding season. Unfortunately, the non-native stoat also has a taste for the Orkney vole and as an easy food source for stoats, the resulting reduction in vole numbers would also have a knock-on effect on our bird population.  

The Mammal Society added the Orkney vole to their first red list of endangered animals at risk from extinction in 2020. Orkney vole’s arrival 5,000 years ago has earned it the classification as a native to Orkney.

Twice a year – in April, and again in September at the end of their breeding season – we survey Orkney voles to estimate their population size as part of the project’s research. Voles can have multiple litters and anywhere from two to 12 pups in a litter. The young are fully weaned within just three weeks. To better understand the vole population in Orkney, our surveyors record signs of voles along one kilometre transects over several sites. These vole signs are grass clippings and droppings found in tunnels across the range of Orkney habitats, including grass and moorland. These, and whether the droppings are old or fresh, give an idea as to whether voles have been in an area recently and are all recorded.

We couldn’t check on the state of Orkney wildlife without our dedicated volunteers monitoring our native wildlife. This year alone our vole detectives donated 152 hours to survey the elusive mammal for which we are hugely grateful! 

We are always looking for more volunteers. No previous survey experience is required – just plenty of enthusiasm for native wildlife. Contact us at: info@onwp.org.uk or fill out the volunteering form on our website www.orkneynativewildlife.org.uk.