St.Hilda's is a small historic church set in a quiet valley near Thornton-le-Dale in the North York Moors. The valley is fringed by woodland, much of it part of Dalby Forest. A stream runs through the valley and there are a series of lakes - in all, the perfect place for bats.
It is not surprising that the church supports four species of bat - Common Pipistrelle, Whiskered, Natterer's and Brown long-eared. We have records of bats at the church dating back around 40 years, but in reality bats are likely to have used the church for hundreds of years. It is only in recent decades that modern technology has enabled more people to record them.
Until around 10 years ago the small congregation appear to have lived alongside the bats without complaint. Since then, there has been an increasing concerns about the bats reported in the media.
The bats that are the cause of the complaints are the Natterer's and Brown long-eared bats. These species both roost in and fly within the church - the other bats mainly live between the layers of the roof and don't enter the main body of the building.
Brown long-eared bat Photo: copyright John Altringham
Whilst the Natterer's and Brown long-eared bats live within the roof and eaves of the church, these species fly within the building before emerging outside at dusk and to a lesser extent before returning to their roosts at dawn. The reasons why the bats do this is not fully understood, but it is likely that it at least partly serves a social function for the colony during the period before it is dark enough for them to emerge into the open. Such behaviour can be seen in other churches, barns and similar enclosed spaces where these species roost.
During these flights inside St Hilda's the bats deposit droppings and urine spots over the walls and furnishings inside the church. It is predominantly this which the church authorities object to. Claims have been made that those using the church have fallen ill as a result and that the presence of bats constitute a health hazard, but there is no evidence that contact with bat droppings or urine carries any particular risk of disease in Britain.
North Yorkshire Bat Group accepts that even though there may be no particular health risks associated with the presence of bats, many people may find the presence of bat droppings and urine throughout the building unacceptable and that measures need to be taken to minimize the problem.
Natterer's bat, Photo: North Yorkshire Bat Group
The bat roosts at St. Hilda's are of great conservation importance. The roosts are maternity colonies, where females gather during the spring and summer months to give birth and raise their young. Bats are long-lived animals (often 15 years or more) and breed very slowly (only one baby a year). They are traditional in their behaviour, returning to the same place year after year. Churches are ideal for these species as they remain undisturbed for much of the time and provide numerous crevices in which bats roost, as well as the enclosed space for pre-emergence flight. If excluded from their roost, they are unlikely to find such perfect conditions elsewhere in the area, so breeding success could decline and the species be gradually lost.
The Natterer's bat roost at Ellerburn is of particular importance as this species is quite rare in the county. Less than 40 roosts are known and that at Ellerburn is by far the largest, accounting for at least 30% of the total number of breeding females currently known in North Yorkshire.
Since concerns about the bats were first raised North Yorkshire Bat Group has made a number of suggestions regarding the management of the bats in order to minimize the problems for the church. These range from temporarily covering surfaces between services to protect them and to make cleaning easier, regular cleaning of the church and the construction of a ceiling within the church to create a roof void so that the bats can fly without depositing droppings throughout the building. The Group even provided a team of volunteers a few years ago to clean the church and at one period English Nature provided funding for regular cleaning to be undertaken. Unfortunately, these ideas have not been acceptable to the church which has challenged the protection which bats enjoy under both domestic and European legislation.
Whilst this legislation prevents anyone harming, killing or handling bats or obstructing or destroying their roost sites, it is primarily a tool to ensure that people properly consider bats when carrying out projects that might harm them. The bats at Ellerburn are not there because they are protected, they are there because it is their home and they have nowhere else to go.
Last autumn, Natural England granted a licence to allow the gap over the church door that has traditionally been used as the main access point for bats to be blocked. This was on condition that monitoring took place then and this spring to ensure that doing so does not adversely affect the bats. Monitoring was completed in May 2012 and shows that bats continue to roost at the church in good numbers. They have found alternative ways in and out of the building and, not surprisingly continue to fly inside. North Yorkshire Bat Group did not object to the granting of a licence as it was not expected to impact on the bats, but we did not see how it would move the situation forward.
As part of their efforts to exclude the bats from the body of the church under licence, the church has carried out other mitigation measures. These include creating access points and installing heating in the roof of the lychgate and making alterations to a nearby barn in the hope of encouraging bats into these places. This mitigation has not been carried out in conjunction with the Bat Group and we consider both measures to be inappropriate given the ecological requirements of the species concerned. To date there is no evidence that bats are roosting in these areas.
Natural England currently have a research project in Norfolk that is examining innovative ways in which the behaviour of Natterer's bats in churches can be manipulated to limit any problems that their presence may cause. We welcome this research and look forward to the results in order that any successful techniques can be applied to problem cases. However, we do not currently believe that this approach can offer an effective solution at Ellerburn because the small size of the building would make limiting the bats to specific areas impractical.
North Yorkshire Bat Group is very keen to resolve the issue of bats at St. Hilda's as quickly as possible, provided that the solution fully takes into account the conservation of these vulnerable animals. We believe that the only practical solution that is likely to achieve this is the creation of a roof void so that the bats can continue to roost and fly within the building, but in an area that is physically separate from that used by churchgoers. We recognise that this solution may cause some changes to the character of the interior and entail some expense, but are willing to work with the church to help source appropriate design skills and funding and to devise a suitable licence application to enable such a project to be successfully completed.
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