29th May 2018

Jo Ferguson, Built Environment Officer for the Bat Conservation Trust (BCT), discusses the exciting joint initiatives ahead to support bat conservation upon the signing of an Memorandum of Understanding (MoU) with the Ministry of Justice (MoJ).

In early 2018 the BCT and the MoJ signed an MoU signifying an exciting new chapter in our joint working!

We will be working together on a number of specific initiatives to meet our common goals, such as protecting our existing bat populations through improving awareness among the built environment sector. To this end, BCT has presented at the MoJ Biodiversity Awareness Day for Estate Staff in March and will again in October, focussing on the importance of built structures to bats and how to consider them during any maintenance or development work.

Other joint working ventures, to share knowledge and promote best practice include creating a lighting principles strategy to plan lighting schemes on MoJ sites to control for the impact of artificial light upon bats. This is based on recent work done by BCT to update theirs and the Institute of Lighting Professionals joint ‘Bats and Lighting’ guidance, which should be published later this year.

Artificial lighting has increased dramatically in the last 10 years, and the type and level of impact on each of our 18 UK bat species depends on whether they are a slow flying and fast flying. This distinction dictates their aversion to light, due to the threat of predation - an evolutionary hang up given that these days their main predators are not birds of prey or owls but unfortunately cats!

Slow flying species are therefore far more sensitive to light as they would struggle to avoid predatory birds, these species include greater and lesser horseshoes, Myotis species and long-eared species. These are more severely affected by artificial light spill onto their roosting, foraging and commuting habitats. They actively avoid the light itself, but also their food source of insects is drawn from dark into light areas, especially where there is UV / blue-rich light sources, causing a ‘vacuum effect’.

However fast flying species previously thought unaffected , that have been recorded feeding around lights (such as the common pipistrelle) have recently been shown to avoid well-lit gaps in the vegetation, which has worrying implications when thinking about our cities and lit gaps between trees.

Therefore when planning lighting for a new MoJ development or retrofitting existing MoJ buildings, considering potential impacts on bats is key to protect our bat populations.

In addition, the MoJ and BCT will also be working together to update the MoJ’s National Bat Action Plan that covers strategies across the estate to protect and enhance habitats for bats. This includes providing advice on roost and habitat creation and linking to landscape management strategies.

The last piece in the puzzle is understanding whether our interventions are working by looking at ways to improve monitoring at bat roosts created as part of mitigation or enhancement schemes on MoJ land.

If you have any enquiries about the work BCT are involved with please contact: Jo Ferguson: jferguson@bats.org.uk

his article was first published in the March 2018 issue of the MoJ Ecology e-News