Survey Techniques

In some circumstances the use of technology such as remote-activated cameras can significantly improve the quality of ecological data collected and the confidence in the outcome of mitigation, while also saving money for our clients through a more cost-effective and less labour intensive approach to work. Some recent examples are outlined below, along with the footage captured in each instance.

BSG Ecology's Gareth Lang is developing a motion sensitive infrared surveillance camera which is responsive enough to detect and monitor bat roosts. Currently, this is very hard to achieve using commercially available infra-red trail cameras, as the speed at which bats enter and leave roosts means that although these cameras may be triggered they seldom capture any footage. The video clip below, from March 2020, shows a lesser horseshoe bat entering and leaving a disused boiler in a church cellar near Monmouth, Wales.

Climbing trees to inspect potential roost features for bats is an effective survey technique. It allows cavities to be examined and assessed, and for evidence of use by bats to be searched for. Given the legal protection afforded to bats and their roosts, this approach allows for a robust assessment of potential roost features, and helps to determine the scope of other follow up work (i.e. more survey or mitigation) that could be required.  BSG Ecology employs a team of ecologists who are both qualified and licenced to climb trees and to undertake surveys for bat roosts. 
BSG Ecology’s Guy Miller, one of our licenced bat ecologists, supported by Adam Long (Access Techniques Ltd), an industrial rope access specialist, has recently conducted aerial surveys of the Grand Bridge at Blenheim Park, Oxfordshire. The aim has been to identify and inspect features of the bridge that have the potential to support roosting bats and nesting birds. The resulting information will be used to inform the approach taken to forthcoming repair work, ensuring that it is legally compliant and that opportunities for birds and bats are retained within the structure following renovation.
The footage below shows lesser horseshoe bats Rhinolophus hipposideros emerging from a stone shed that supports a maternity roost. It was captured in early August 2019 by BSG Ecology’s Guy Miller and Hannah Daniels, using one of BSG Ecology’s FLIR T650sc thermal imaging cameras. The location is near Abergavenny, Monmouthshire.
At BSG, we regularly use thermal imaging technology to supplement more standard methods of data collection, and answer questions that need to be addressed in Ecological Impact Assessment and Habitats Regulations Assessment work. In some circumstances, it can provide a more robust evidence base for our clients’ projects. The value of thermal imaging in wildlife recording has been recognised by NHBS, the largest supplier of wildlife, ecology and conservation books and equipment in Europe, who have used footage provided by BSG in their latest article entitled ‘NHBS Guide to Night Vision and Thermal Optics.’ Most of this footage has been collected in the course of commercial work.