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 increasing concerns about the bats have been 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 two 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.

Around 200 Natterer's bats use the building to 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.

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 campaigned for legislative changes. 

Whilst 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.

In 2011 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 to ensure that doing did 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.

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 barn to the south in the hope of encouraging bats into these places. This mitigation was not suggested by 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. 

In 2013 Natural England sponsored a research project to examine the ways in which bats used the church with a view to finding a suitable solution to the problem.  This involved watching and listening for bats, radio-tracking of bats and ringing over several months.  The research confirmed the importance of the church, especially for roosting Natterer's bats.  Whilst a few additional small temporary roosts of bats were located during the project the church was the only significant roost within a large foraging area extending over 36 square kilometres of the surrounding countryside.

Following completion of the research a licence application was submitted to Natural England to permit the exclusion of bats from the inside of the church.  An argument was presented that the bats roost in the roof of the building from where they have direct access to the outside of the church and so they have no need to access the interior of the church.

North Yorkshire Bat Group does not dispute that the bats roost in the roof of the building from where they have direct access to the exterior.  However, we do not agree that the bats do not need to access the interior.  At dusk some of the bats make considerable effort to access the inside of the church from their roost sites in the roof, fly around inside the building for a lengthy period of time and then make considerable efforts to exit the building at the eaves.  Just because we don't know why they do this or what subset of the population exhibits this behaviour does not mean that it does not serve some important function to the bats.

After consideration by Natural England a licence was granted in October 2013 to exclude bats from the interior of the church.  North Yorkshire Bat Group critically examined the application and carefully considered how to respond.  In view of the tremendous harm that publicity around this case is causing to bat conservation we decided not to object to the licence.  Instead, we did respond to Natural England requesting a number of amendments to details of the licence method statement, which were favourably received.  We also expressed our serious concerns that excluding bats from the interior of the church may effectively result in Natterer's bats abandoning the church entirely, which would have a serious impact on their Favourable Conservation Status.  If this were to happen the licence requires that the exclusion be reversed, but there is no guarantee that to do so would result in the bats returning.

North Yorkshire Bat Group will continue to closely follow the situation at St. Hilda's, particularly the results of monitoring in Spring 2014.  If we believe that the exclusion has resulted in an adverse impact on the Favourable Conservation Status of bats using the church we will consider what further action is appropriate.

Meanwhile, Natural England currently has a separate 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.

Your views on this issue are welcomed.  Please email nybats@btinternet.com.