As part of our commitment to give back to our community and the environment, DowlingDodd are delighted to be supporting Kernow Conservation.
As part of this support, the team were out and about again, this time at The Trelusback Foundation for Wildlife Conservation site. The site was originally owned by Keith Wilson, and was originally farmed, but after watching the wildlife return when farming was paused, Keith decided to manage the 29 acre site for wildlife and then donated the site to the Trelusback Foundation for Wildlife Conservation. As well as protecting the wildlife, the site is used for educational purposes and as a receptor site for animals and plants which have to be relocated or reintroduced.
The Trelusback Foundation have a number of Conservation projects underway at their site, but today, we were working on managing the habitat for their Water Voles.
When we arrived, Joe Marshall from Kernow Conservation explained in more detail what this habitat maintenance would be. Water Voles are herbivores, eating up to 85% of their body weight a day and can weigh up to 350g. To achieve this, they will graze on up to 227 species of plant. Our aim for the day, was to clear some of the Willow around the lake which was creating dense thickets and crowding out the plant vegetation essential for the voles.
“For those gardeners out there: Willows have extremely high rooting hormone levels which allows them to put down roots where branches touch the ground enabling them to spread easily. Willow can be used as a rooting hormone by making ‘willow water’. Chop fresh willow branches into small pieces and soak them in water for a few days and then use that liquid to soak plant cuttings before planting them in soil.”
Once Joe had explained the ‘why’, he handed us our tools for the day, bow saws and loppers, and pointed us in the direction of the trees that needed clearing. After about an hour and a half (blowing our own trumpets just a bit here, and Joe’s, what a Trojan!), we had created a pretty impressive pile of cleared Willow and a lovely new view of the lake!
After a break for lunch, Joe took us for a tour around the lake and explained a bit more about the Water Vole project.
Joe explained that we will see figures such as a 98% reduction in Water Voles across the whole of the UK by the end of the last century, and they estimated that only 100,000 Water Voles across the whole of the UK were surviving by the 1990s, which was virtual extinction, and Water Voles were completely wiped out in Cornwall by the 1990s. This was due, essentially, to human activity such as straightening rivers and industrialisation, causing habitat fragmentation and loss, but also predation by American Mink which were brought over in the 1920s for use in the fur trade. There were many farms across the UK and were used as a ‘side burner’ for a lot of farms because they were relatively low cost. The Mink are highly evolved predators and sometimes escaped or were deliberately released.
Whilst Water Voles had been reintroduced in Bude in 2014, it wasn’t until 2022 that they were reintroduced to the south of Cornwall, at Trelusback by Kernow Conservation, and a second release was carried out in 2023.
Water Voles usually have up to five litters a year, with five/ six in a litter, starting about now. Those litters will then be able to breed themselves within about 6-8 weeks. This sounds like a lot, but there is around a 70-75% loss of the population every winter, just through harsh weather, predation, as they are a keystone species and lack of food.
Whilst normally enough would survive to keep populations stable, the release of American Mink was devastating for water voles. Unlike our native Stoats and Weasels who can’t / won’t go into the Water Vole burrows, Mink will, and they are voracious eaters who will kill even if they don’t need to eat. This means that monitoring for Mink is extremely important. Joe showed us a Mink Raft which they use, along with camera traps. Inside the raft there is a little tray with clay in it. The thinking behind these is that the Mink are curious, will come and have a look, walk through and leave their footprints so you can see if they have been in the area. Thankfully, there has been no evidence of Mink on this site. Conveniently, for monitoring purposes, female Water Voles also use the rafts for marking their territories with their droppings. There have also been additional small rafts placed in all ponds and streams at the Trelusback Foundation site to assess the number of breeding females. Some of these rafts have been used by voles when eating and evidence of their diet is seen. Another indicator of voles being present were, as Joe showed us, the very distinctive diagonal cut on the vegetation, where the voles have climbed up, bent them right down and cut them off with their sharp teeth, and you can see evidence of this all around the lake.
When asked “what are the benefits of Water Voles”, Joe explained, they are very plump and can make a very tasty morsel for anything up the food chain. Their grazing encourages plant diversity, their burrow systems increase microbial activity in the soil and their droppings create nutrients which improve the soil structure, all of this meaning they are considered to be a keystone species.
Since the reintroductions, the Water Voles appear to be thriving and have now spread quite some distance. The River Kennall runs through this site and some voles were also released into this. As well as significant activity found on the lake and many ponds, they have found evidence of burrows right up to the source of the River Kennall which would show evidence of breeding, and whilst they haven’t found burrows, they have found droppings as far down as Devichoys Wood.
After our tour of the lake, we spent another happy couple of hours creating another impressive willow pile, which, Keith told us would be left to rot down on its own, creating habitat for other species.
Leaving the site, there was a very mild disappointment that we didn’t see any Water Vole, not even a plop, but we did have that lovely self-satisfied feeling that we had done our bit to help such a keystone species. We can’t wait for our next volunteer day and would like to say a very big thank you to Kernow Conservation, Keith and the Trelusback Foundation for having us.
