How water voles left their riverside homes for Glasgow grasslands

The water vole was once common in waterways across Britain. It is sometimes mistaken for a brown rat, though it has a chubbier face, smaller ears and a shorter, furrier tail. When Grahame wrote his story in 1908, he would have been familiar with the 'plopping' sound the voles make as they dive into the water.

But over the past century their numbers have plummeted and they hold the unhappy distinction of being the UK's fastest declining mammal. From an estimated population of eight million in the early twentieth century, there are now only around 132,000 water voles left. They have disappeared from 94% of sites where they once lived.

Homes under threat

The vole has come under pressure from habitat loss due to changes in agriculture and land use. An estimated one-third of all semi-natural vegetation once available to water voles on farmland has been lost in the UK since 1940, and watercourses in urban areas have been diverted into channels for development.

The remaining habitat suitable for water voles is often fragmented leaving populations isolated, and isolated populations are more vulnerable to extinction. In some areas of the country additional rapid declines coincided with the arrival of American mink. Mink were brought to Britain in the twentieth century to be bred on fur farms. Escaped mink colonised waterways and have now established themselves in nearly all parts of Britain apart from the far north of Scotland.

Water voles are now a protected species and there are efforts across the country to increase their numbers, including habitat creation and mink control.

A change of venue

In Britain, water voles are associated with wetland habitats such as rivers, lakes and marshes. They build their homes by burrowing into riverbanks, eat a wide range of riverside plants and use the water to forage and escape predators.

In 2008, however, a population of voles was discovered living in the East End of Glasgow, a kilometre away from any water. Cath Scott, Biodiversity Officer at Glasgow City Council, explains:

'The initial call from the public was to the Environmental Health office as residents were concerned about rats. When biodiversity officers visited, it was soon realised they were actually water voles. And then we did quite a lot of head scratching working out what they were doing there as they were a kilometre away from any water!'

The biodiversity team and countryside rangers already ran surveys for water voles, but they had been focusing on the city's waterways. Once they expanded their surveys, they found the voles living in a wide variety of urban grassland sites, including parks, road verges and derelict land. One primary school even has them in their grounds.

Research led by the University of Glasgow has shown that the voles seem to be doing better on the grassland sites than by water. 'There are some very high population densities,' says Cath, 'One of the sites actually has the highest density of water voles in the country and the population is now recognised as nationally significant.'

Living a fossorial lifestyle

Unlike their riverbank cousins, the grassland water voles spend more of their time underground and have adapted a lifestyle that is termed fossorial, which means burrowing. They are exactly the same species but have changed their behaviour to live in grasslands.

Though unusual for Britain, this fossorial behaviour is not uncommon in voles in areas of mainland Europe.

Spreading the word in Glasgow

The council has worked with a range of organisations to raise public awareness and has set up the Glasgow Water Vole Project to bring together expertise. Information is available online about Glasgow’s unique water population, with leaflets having to be specifically written to cover water voles living in grassland.

'Once people know what the animals are, and are over the surprise of water voles living in grassland, they are impressed that a threatened animal is thriving in the city,' says Cath.

'Environmental education is offered to schools throughout Glasgow, and in the northeast of the city this has a strong focus on grassland and wetland water voles. The Countryside Ranger Service, Seven Lochs Wetland Park and RSPB Scotland all provide outdoor education sessions with schools to learn more about wildlife and give a helping hand. And volunteers are out weekly carrying out habitat creation and management projects.'

A key requirement for grassland water voles is long grass to provide cover and food, and in Scotland it is this habitat that is legally protected.

'So we are working with community groups and schools to enhance areas of long grass by planting additional wildflowers,' says Cath. 'This looks more attractive to people and has the added benefit of helping pollinating insects.'

The council also work with a range of professionals in the city, for example explaining to developers what the habitat needs of the voles are at the start of new building projects, so they leave space for the voles from the outset.

A plan for the future

The council is one of the partners in the Glasgow Water Vole Project, which aims to co-ordinate the work of conserving and raising awareness of the voles.

The project is currently putting together a conservation action plan to protect the voles. Cath says, 'Although a lot is known about wetland water voles in the UK, there is a lot we didn't know about their grassland fossorial equivalents, so we have had to develop new methodologies just for them.

'We are working together to cover as many aspects as we can. The more we can coordinate, the more we can achieve.'