We were commissioned by Baxter Homes to complete update bat emergence surveys of a detached house in Ascot, Berkshire in order to inform a European Protected Species Mitigation (EPSM) Licence application for the demolition of the building. The initial bat surveys were undertaken in 2013 by another consultancy in order to inform the planning application for replacement of the house with two new detached dwellings and garages. These surveys had revealed that the building supported an occasionally used roost of approximately one soprano pipistrelle bat and one brown long-eared bat. Planning approval was granted shortly after the submission of their bat survey report which made recommendations for bat mitigation measures to be incorporated into the site. An EPSM licence was required to enable the works to proceed in accordance with the legislation that protects bats and their roosts. We completed update surveys to ensure that the licence application was as robust as possible and that bat usage of the site had not significantly changed since the previous surveys and assisted Baxter Homes with the EPSM Licence application.
To provide sufficient information to enable the successful granting of the EPSM licence, we undertook two emergence surveys in May and June 2014 to supplement the single survey undertaken in May 2013. Each of the bat surveys involved an update internal and external assessment of the building immediately followed by a dusk survey which involved a team of experienced surveyors watching the building to see if any bats emerged from it during the course of the evening/night. To complete the surveys, the surveyors used ultra-sonic bat detectors which convert the echolocation that bats produce into a sound that we can hear. The echolocation was also recorded and later analysed using specialist analysis software. The surveyors use this information together with field signs such as the size, shape and behaviour of the bats to identify the species present. However, with closely related species that can be difficult to distinguish in the field, we can also collect bat droppings from a roost site and send them off for DNA analysis.
We then used the information gained from the surveys and any subsequent analysis to establish the conservation importance of the roost/s as well as the entrance/exit points used by the bats and any other information necessary to design an appropriate mitigation strategy. This directly informed the EPSM licence application which was submitted in July 2014 shortly after the completion of the surveys.
The EPSM licence application was successfully granted in early September 2014 on the first attempt with no requests for further information from Natural England. This enabled the works to proceed at the earliest available opportunity without further delay. We then worked closely with Baxter Homes to ensure that the works were undertaken in accordance with the licence. This involved giving advice on the installation of bat mitigation features as well as conducting a supervised roof strip to ensure that the removal of roof materials was undertaken in a manner that was highly unlikely to harm bats.
We also conducted a post-development mitigation check and was pleased to see that Baxter Homes had installed all agreed mitigation features correctly and had erected several additional bat boxes as enhancement features for bats. At this stage the development was nearing completion and we were delighted to see how the site had transformed since our visits earlier on in the year.
We are looking forward to conducting monitoring of the mitigation features in 2018 and hope to see bats occupying the boxes and tubes!