HAWCE committee member Mike Webb provides an introduction into recently issued guidance that is of relevant to architectts, engineers, contractors and developers. Mike is an ecologist working at Worcester-based SLR Consulting Ltd.
There are 17 different species of bat that breed in the UK. All of these bat species, their breeding sites and resting places are fully protected by both UK and European law. In the UK, bat populations have declined considerably over the last century due to a number of factors. Though some of these species are quite common and widespread, some have become rare and seven of our native bat species have now been listed as UK priority species.
Some bat species (often the rarer ones) have been shown to be impacted by significantly lower lighting levels than others and certain colour temperature environments also play a factor in the level of impact. However, all bats require dark roosting areas, corridors through the landscape and habitats to feed.
Newly-built developments - or even the modification to lighting regimes in an area - can potentially have an adverse impact on how bats use this area and its surroundings.
Late in 2018, a partnership of The Institution of Lighting Professionals (ILP) and the Bat Conservation Trust (BTC), along with ecological consultants, launched a guidance note as part of the Bats and the Built Environment Series - Bats and artificial lighting in the UK (08/18).
This guidance, which is far more detailed than previous released, provides useful information on how different light types can impact upon bats in different ways and makes recommendations as to how lighting can be designed to avoid or reduce harmful effects upon bats and the habitats they use, whilst remaining fit for purpose.
The guidance is available free to download on the ILP website: https://www.theilp.org.uk/documents/guidance-note-8-bats-and-artificial-lighting/
Those who have recently taken a walk down the riverside in Worcester may have noticed that some different and unusual new forms of lighting have been installed. This is in fact bat-friendly lighting! Worcestershire is probably near the north-eastern edge of the lesser horseshoe bat's range, but the bats are particularly vulnerable to disturbance and sensitive to high-power lighting. When the regeneration of the riverside along Severn Way included new bollard lighting, the bat colony under the cathedral would have been obstructed from returning to their roost, or dispersing into the countryside, so a more sensitive solution was sought. For more information on this lighting, visit: https://www.solar-eye.com/case-study-worcester-riverside/.