BATS ABOUT CORNWALL
PUBLISHED: 15:14 19 May 2014 | UPDATED: 12:36 30 August 2017
Bats are often portrayed as slightly sinister supernatural beings, but our British bats are actually gentle, insect-eating mammals
As the days get gradually shorter, thoughts often turn to the mysterious creatures of the night, both real and imagined. Bats are often portrayed as slightly sinister supernatural beings, with the Halloween images of blood-sucking vampires still fresh in our minds, but our British bats are actually gentle, insect-eating mammals, which really need our help to survive.
'Why do we need to protect bats, you may ask. Populations of many bat species - we have 17 species in this country - have declined in the last century, and are still under threat from development or land management that affects roosts, or features of the wider landscape that bats rely on'
Why we do need to protect bats, you may ask. Populations of many bat species (we have 17 species in this country) have declined in the last century, and are still under threat from development or land management that affects roosts, or features of the wider landscape that bats rely on, for example hedges, which provide routes for bats to travel between their roosts and feeding areas. For these reasons, bats are protected by law in the UK, and some of the more vulnerable species are also listed as priority species for conservation in the UK Biodiversity Action Plan (BAP) and more locally in the Cornwall BAP.
Cornwall Wildlife Trust contributes to bat conservation through appropriate management of their nature reserves. One of the long-term management aims at Prideaux Woods Nature Reserve includes the gradual removal of conifers and their replacement with native broad-leaved trees, to benefit bats and other wildlife. Bat ecologists from Cornwall Environmental Consultants (CEC, which is the trading arm of Cornwall Wildlife Trust) have been working closely with the Trust to ensure that the tree felling causes minimal disruption to the greater horseshoe bats that roost within the site, by retaining selected trees that are close to existing roosts.
With a healthy portfolio of successful projects, CEC’s work has often achieved a positive outcome for both bats and our clients. Sometimes mitigation, for example bat boxes and roost areas, is used by bats almost immediately, but in other cases, it can take a few years before the true potential of bat mitigation is realised.
In one recent example, bats moved into their new accommodation above almost as quickly as the Isles of Scilly Wildlife Trust moved into their new offices below. CEC undertook bat surveys of the existing building on the site, prior to its demolition and replacement with new offices for the Isles of Scilly Wildlife Trust.
Bat droppings were found in the building, but follow up bat surveys did not record any bats using the building. During the supervised demolition, three common pipistrelle bats were found, and our licensed bat ecologist was able to move them to a bat box which had been erected on an adjacent building.
The new building included simple but specific mitigation for common pipistrelle bats. Within several months of the building being completed the Isles of Scilly bat group found common pipistrelles already roosting within the building and further monitoring is planned. Sometimes, it may take a little longer for the full potential of artificial bat roosts to be realised.
At the Cornwall Hotel, Spa & Estate, near St Austell, we obtained bat licences for the work proposed to create the hotel, incorporating and adapting mitigation proposals for bats. Pre-development surveys of the site identified numerous bat roosts within the site, and these had to be retained or replaced as part of the construction works.
The new bat roosts provided within the site are being used by five different species of bat; lesser and greater horseshoes, common pipistrelle, brown long-eared bat and the barbastelle bat. Different species of bat utilise the different types of roosts provided (e.g. underground roosts, bat boxes on trees and allowing access into roof voids) at different times of year. For example, the horseshoe bats utilise the underground roosts for hibernation in the winter, barbastelle bats use bat boxes in the summer and the horseshoe bats have used the barn roost in the summer, which is also sometimes used by barn owls!
'The tunnel roost has seen increasing use year on year - at the last count, 40 bats were seen, including young.'
The most exciting recent discovery is that one of the tunnel roosts is now being used as a lesser horseshoe maternity roost. It is likely that the bats now use this roost to look after their young because of works undertaken to increase the humidity within the roost, and the addition of better perching’ features. The tunnel roost has seen increasing use year on year - at the last count, 40 bats were seen, including young.
Although bats have suffered decline in the recent past, these examples show that bats are adaptable and will use roost sites if provided, as long as they are carefully designed and well-sited. It is possible to provide practical help for bats, to ensure that they can survive, and hopefully thrive, both in Cornwall and beyond – with our help the future could be a little brighter for these fantastic little creatures.
CEC has been advising clients of all types (from private home owners to local authorities and multi-national companies) about bats, and other ecological and landscape issues for over 20 years. CEC have a dedicated team of licensed and experienced bat ecologists, who provide surveys and advice on all kinds of bat issues, from advising on how to retain a bat roost within a property where an extension is proposed to undertaking a detailed set of surveys to identify how bats are using an area of land earmarked for a large scale development.