The Building Conservation Directory 2022

138 T H E B U I L D I N G C O N S E R VAT I O N D I R E C T O R Y 2 0 2 2 C AT H E D R A L C O MM U N I C AT I O N S MANAGING THE IMPACT OF BATS IN CHURCHES CATHY WALLACE B AT AWARENESS is essential for everybody working with historic buildings, even if they don’t think they have bats. In most cases the fabric, makeup and even the purpose of old buildings will have altered in the years they’ve been standing, and one no doubt unintended consequence of their complexity, whether original or acquired, is that they can be extremely appealing to bats. We don’t know for sure how many churches currently house these creatures. A study carried out in the 1990s estimated more than 60 per cent of pre-16th century parish churches around England have a winged population of some sort or other. We also don’t know for sure why bats are using some churches and not others. But, we can safely say that some of the reasons they are drawn to churches include their complexity: the nooks and crannies that make ideal roosts, the range of microclimates that suit varying functions from maternity roosts to hibernacula, and the churchyards and often wider habitats beyond that are rich in biodiversity, most notably insects upon which the bats can feast. These charming, winged mammals are very similar to us as human beings in many ways, despite the more frequent comparisons to rodents. Study a bat skeleton and the resemblance to a human skeleton is very obvious, barring the extremely long ‘fingers’ which make up the structure of a bat’s wing. Like us, bats have a long lifespan (relative to their size) and a slow reproductive strategy, producing just one pup a year and investing time in nourishing and raising their young. Inherently social creatures who roost and hibernate in large groups, bats are important in a healthy functioning ecosystem and their presence is good news for biodiversity. But it’s not always great news for the congregation and those looking after historic churches. Bats aren’t house-trained, or church trained in this case, and their droppings and urine can create a cleaning burden and damage the historic fabric of the building, including the monuments. Bat droppings, which are made up of dried insect remains, rarely create any damage themselves, but if they are left they can encourage algal growth which can damage surfaces, in particular marble and alabaster. Bat urine, however, contains uric acid, sometimes in high concentrations, which can corrode metal, etch polished surfaces and stain light-coloured plastic and porous stone like marble and alabaster. Contrary to popular belief, there’s little risk to human health from the presence of bats. We do advise wearing PPE including gloves and masks when clearing large amounts of droppings, as there can be a risk of mould and bacteria accumulating. If it’s ever necessary to handle a bat, which would generally involve removing a dead one, wear gloves. But often it’s their nocturnal nature and the myths and legends that surround bats that causes concern, rather than any risk to health. The Bats in Churches project, a five- year partnership between the Church of England, Natural England, Bat Conservation Trust, Historic England and the Churches Conservation Trust was set up to help churches and their communities live with their bats. As part of this a new licence, the Bats in Churches Class Licence, was created and the project is working with more than 100 ancient churches across England to create bespoke solutions to the issues created by bats. In trialling a range of solutions, developed in partnership with qualified and licenced bat ecologists, church A brown long-eared bat which can be found roosting in old buildings throughout the UK (Photo: Chris Damant, Bernwood Ecology)