Water voles: the mini eco-system engineers of the Trossachs
Beavers typically get all the glory when it comes to building ecosystems, but water voles also play an important part in shaping Scottish wetlands. Though not as well-known, these small but mighty creatures are eco-system engineers, positively impacting biodiversity and helping plants grow.
Eco-system engineers are animals whose very existence can change the environment they live in. A famous example of this is the wolf reintroduction program in Yellowstone National Park.
For water voles, their existence can impact soil and plant biodiversity around their burrows. When water voles dig into the ground around river banks, they move nutrients around, bringing some to the surface. Studies have shown that this activity can increase the soil nutrients needed for plants to grow. Above ground, their eating habits can help shape the ecosystem which they live in.
Like beavers, water voles are semi-aquatic mammals. They have large front teeth which continue to grow throughout their lifetime. These small herbivores eat over 229 different plants and use their prominent incisors to cut thick grass – their favourite snack.
Think of them as small lawnmowers. Their grazing can help control vegetation growth, making room for wildflowers and other native grasses to grow around the water banks and riparian zones.
A water vole skull. Notice the large incisors perfect for cutting rough grasses.
Bringing water voles back to Scotland
In 2008, Environmental Forester Katy Anderson realised that despite having perfect water vole habitats, there were no signs of these busy creatures in Queen Elizabeth Forest Park in the Trossachs. FLS worked closely with riparian mammal expert Derek Gow to trap and relocate water voles, a first in Scotland.
For the next three years, the team worked hard to relocate over 1000 animals in the 15 areas chosen to house the new tenants. Prepping release sites also meant monitoring and managing mink populations in the area.
A mink matt is a monitoring device used to survey mink in an area.
Mink is a fierce predator of water voles. Their slight stature allows them to chase the water voles into their burrows, taking away any escape. Mink are not native to Britain and were released after a decrease in the fur industry, not knowing the potential damage to native ecosystems.
We monitor mink using rafts, which compress their footprints, allowing our team to understand what's in the area.
Creating a water vole community
Today, we work closely with The Loch Lomond and Trossachs National Park Authority and other partners to maintain the water vole population, one that has expanded to a range of 100km²!
We rely on our community and volunteers to survey and help with mink control as the water voles venture further and further away from FLS sites.
Though humble, these little engineers can impact small ecosystems around our wetlands. They are a gentle reminder that even the smallest animals can significantly impact our environment.
Katy Anderson says the water vole reintroduction program is one of the most successful projects of its type in the UK, winning it an award at the 2017 RSPB's Nature of Scotland Awards.