My Week of Work Experience with the Snowdonia Society
by Mark Bridges
In July 2017, I participated in a water vole survey with Bill Taylor – Assistant Warden for Llyn Tegid & Penllyn – as part of my week of work experience with the Snowdonia Society.
To begin, Bill showed us how to identify the presence of field and water voles, otters and shrews. The signs of these mammals were very subtle and before then I would never had noticed them even if I walked right over them! But after being shown examples in the wild it became much easier to locate and identify them.
We split into two groups, one on each side of the river, and moved slowly along the bank. At the beginning we looked for signs of field voles since they are very similar to water voles. We parted tussocks of grass to find feeding stations and latrines. The voles cut the grass at a distinctive forty-five degree angle, and leave small droppings in specific areas. We heard what must have been a juvenile field vole squeak, but left it alone so as not to traumatise it. Every time we pushed the grass back into place to avoid damaging the voles’ habitat.
Reading the signs
The differences between water vole and field vole signs are quite subtle. While water voles are much larger than field voles, they are quite similar and their habitats overlap so distinguishing signs of their behaviour is quite difficult. The larger water voles have larger droppings and tend to cut larger pieces of grass than the field voles. Water vole latrines and feeding stations are often right on the bank of the river and sometimes in the water. They have runs where they frequently use or travel through the same area.
Bill had chest waders and was in the river for the majority of the survey. He got a unique viewpoint and was constantly revealing marks of water voles that we would never had found ourselves.
Before the survey, David Thorpe – Biodiversity Specialist for Natural Resources Wales – set up a mink raft and a camera trap. The mink raft is a floating board tethered to the bank with a tunnel through which animals could walk. Inside the tunnel was some soft clay, to record the footprints of the animals that walk across it. Mink like to explore new things and are attracted to the tunnel. It is important to check for mink, especially in areas with water voles, since they are an invasive species and have hunted water voles to extinction in some places. Mink were originally brought to Britain from America for the fur trade, and many of them escaped into the wild. Because mink can hunt water voles both in their burrows and in the water, the voles have no way to escape. Fortunately, there were no mink footprints on the raft, only a few water vole droppings, which was a good sign.
A sweet treat for a lucky water vole!
The camera trap was in a crack in the bank and Dave staked a piece of banana to the ground in front of it. The footage from the camera was fascinating. It didn’t take long for a water vole to find the banana, and the greedy little thing ate the whole thing itself (!) , eating late into the night. Even after the banana was gone, what we assumed was the same vole came back to lick the stake and nibble the ground around it. The poor thing wanted more banana, it was probably the best thing it had ever tasted since they normally only eat grasses on the bank of the river. The camera also caught swimming water voles, a short-tailed field vole, grey wagtails, shrews and even a small fish. Their behaviour was very interesting, the wagtails always seemed to be walking in the same direction, suggesting their nest was somewhere further along the bank. One of the water voles climbed straight up the side of the bank, an almost vertical slope, and the shrews moved extremely fast for their size.
The photos below from the camera trap show the water vole approaching the staked banana, seeimingly asking for more having eaten the lot, and swimming away, freshly replenished! Third photo from left: grey wagtail.
A valuable insight
Overall, the survey was very successful, with far more recordings of water vole signs than the previous year, when an identical survey was taken along the same stretch of river. The leaders were extremely knowledgeable and the whole experience was very educational. We also saw other wildlife on the survey, including red damselflies, a grey wagtail, a kestrel (which may have been a merlin) and golden-ringed dragonflies (the largest dragonflies in the UK).
I thoroughly enjoyed the experience and gained valuable insight into how a survey is performed. I had only done a few surveys before, mostly on bees and birds, but never along a river or in such detail. When I return home from work experience I will contact my local wildlife groups and see when similar surveys are planned and join in.