Tamar Lakes sit on the border of Cornwall and Devon and both Upper and Lower Tamar Lakes are designated as County Wildlife Sites. Earlier this year we had to temporarily shut Lower Tamar Lake due to the health of our ash trees which are suffering with ash dieback. Ash dieback is a fungal disease that is now widespread across the UK but which originated in Asia.

The introduction of this disease to Europe about 30 years ago through the importation of trees and subsequent natural spread is having a huge impact on our native ash as they have a limited defence against the disease. This disease can make our ash trees brittle and infected trees show signs of this largely on the leaves and the trunk. You can read more about ash dieback here.

We had to temporarily close Lower Tamar Lake to remove the dangerous ash trees to protect our visitors (walkers, bird watchers, and anglers), volunteers and staff. We have only removed the ash trees which are overhanging the narrow footpaths as they are a risk to people. The ash trees further into the woodlands where there are no footpaths are being left alone to allow nature to take its course.

We worked with South West Water and their contractors (Dartmoor Tree Surgeons) to ensure that as many of the ash trees were retained as possible whilst still making it safe for people now and in the future.

You may see that some of our ash trees are cut close to the ground and some have been cut at quite a height. A variety of trunk stumps between 2ft and 18ft have been retained along our pathways. Some of these stumps may re-sprout with new shoots and leaves and some may die. Dying or deadwood which is still standing (like these stumps) is a very valuable part of a woodland habitat. Standing deadwood is the rarest kind of deadwood in woodlands and has a huge part to play in nutrient cycling and is also home to a range of animals, plants and fungi. Over time we may see invertebrates like beetles, birds like great spotted woodpeckers, mammals like bats and voles using this new habitat. Some of the ash trees which required safety works had old bat boxes on so we made sure that all of the boxes were empty (no bats or any other animals inside) before the works started and ensured that no animals were disturbed.

Whilst all of this tree work was going on, our volunteers at Burrator Reservoir, made us 30 brand new boxes to put up on site. These boxes have been sustainably sourced and handmade from fallen trees at Burrator Reservoir. These boxes have been used to replace all of the old boxes (even the ones on the ground!) and to create more room for bats.

We've since put up our 30 new bat boxes which are of four different designs. These designs offer different structured roost spaces for bats that have different preferences, for example, those who prefer smaller crevices over larger cavities. You can see these high up in the trees (approximately 3 meters from the ground) from Upper Tamar Lake car park all the way down to Lower Tamar Lake. We have put the boxes on woodland and field edges and in our meadow hoping to attract different species of bats.

From our surveys in recent years, we know that we have at least 7 species of bat using Tamar Lakes sites which include the common pipistrelle, soprano pipistrelle, brown long eared, Daubenton's, noctule, serotine and whiskered bat. These species will be using the lakes to move from place to place, forage, hunt and roost. Most of these species take well to a bat box so we hope to see them using our new boxes in the future.

As we always aim to monitor our bat boxes we have ensured that no boxes are left or put up on vulnerable ash trees which could become unsafe in the near future. This is for the longevity of the boxes (we don’t want our new boxes to fall with a tree!) and for the safety of our staff and volunteers.

We will now leave the bat boxes for several months to let them bed into the site and we will aim to monitor these bat boxes later on in the summer. If you would like to be involved in the monitoring of these boxes in the future just email me on [email protected].

Thank you to our Tamar Lakes team; Laura, Chamonix, Ethan, Gary and Rick for helping to put these bat boxes up, to the Burrator Reservoir volunteers for making these fantastic boxes and to Alan, South West Water and Dartmoor Tree Surgeons for managing ash trees sensitively.