A bat scoping survey was carried out at a mill site in Huddersfield which determined
the site to have a high potential for supporting roosting bat species.
As the site had been considered to have a high potential of supporting bat roosting sites, we recommended that dawn/dusk emergence surveys should be carried out to establish the absence/presence of roosting bats. After conducting the three emergence/re-entry surveys Common Pipistrelle bats were determined to be roosting within the mill complex and there was also evidence and sightings of Brown Long-eared bats and Mytosis species. As a result, our consultant informed our client that a Bat Mitigation Licence should be applied for from Natural England, and a mitigation plan devised so that development would cause as little impact on local bat populations as possible.
JCA advised our client that it would also be necessary to undertake a hibernation survey to determine whether those bats were using the site for hibernating during the winter months. Three surveys were carried out, one per month from December to February. The licensed bat ecologist searched the entirety of the complex for hibernating bats and bats in torpor within the building to determine whether the mill was a key bat hibernation site. No bats were found to be hibernating or present during the hibernation surveys in December, January or February. However, it was concluded that brown long-eared bats were using the site as a day roost and the common pipistrelle as a maternity roost. High levels of bat foraging and commuting activity were also observed over the canal adjacent to the west of the site.
As part of the plans, the common pipistrelle roosts were to be retained post-development and new roosting features were to be created within the roof void of the building to mitigate the loss of the brown long eared roost. Wildlife friendly lighting was also to be utilised throughout the site and landscape planting of native trees and shrubs was to be carried out to the borders of the site. The inclusion of these features and the subsequent monitoring of bat usage is expected to improve the ecological value of the site for bats!