Bat breeding area given Local Wildlife Site status thanks to Yorkshire Water’s Batman (1)

A 28-hectare site on the moorlands of Harden, Barnsley has been granted Local Wildlife Site (LWS) status following its discovery as an important habitat for protected bat species.

 This follows a year-long study by ecologists in Yorkshire Water's Environment Assessment Team (EAT), working closely with local experts at the South Yorkshire Bat Group (SYBG). LWS status will help to protect the bat populations and their habitats on the site in future.

The project began when Sean Davey, lead ecologist at Yorkshire Water, found bat droppings at the entrance to an abandoned mine on a moorland above a Yorkshire Water  reservoirs. The research that followed discovered other mine shafts nearby, and soon confirmed that this was an ‘autumn swarming’ site for several species of bat - where they go every year to mate in the autumn. Because of its important role in breeding, swarming is crucial for maintaining healthy bat populations in the wild.

An intensive year of surveys in 2023 was led by Davey, a bat specialist and SYBG member, supported by other volunteers from the local bat group. The team used 24/7 acoustic monitoring and filming with night vision equipment to monitor activity and confirm the different species of bat visiting throughout the year. They also used specially licensed techniques to safely catch swarming bats, in order to identify the individual species and assess their breeding condition.

The results of the year-long study have shown the importance of the mines at Harden for four species of swarming bat. The research also found that some of the same species return in winter to hibernate in the sheltered pits. Another four kinds of bat were recorded foraging over the moorlands in summertime, taking the total recorded to eight species for the site. These findings have convinced the Barnsley LWS panel that it is an area worth protecting for the future.

Cllr Robin Franklin, Cabinet Spokesperson for Regeneration and Culture, said:  “It’s great to hear that we have protected species in our borough.  Local Wildlife Status (LWS) will help to keep their habitats safe.  Bats as a group provide an excellent indicator of the wider health of their eco-system; monitoring projects like this are therefore an important tool for conservationists.  Warming climates in coming years may see new bat species spreading north from their existing rangers further south.  Further monitoring could help to detect species not yet found in Yorkshire.”

Sean Davey, lead ecologist, Yorkshire Water, said: “Bat swarming sites are more commonly found in wooded lowland areas so it’s particularly interesting to find swarming happening up on this exposed moor with no trees around! It is currently the only known bat swarming site in Barnsley and one of few places in South Yorkshire where this activity can be studied.

“Swarming sites are thought to have quite a large ‘catchment’, with tiny bats flying impressive distances from the surrounding areas in order to swarm and find a mate. Female bats only give birth to one offspring each year, so swarming in the autumn is critical for raising the next year’s generation of bats.

“Because of its importance for breeding, we need to know where bat swarming happens so that key sites can be mapped and protected. Better information informs better conservation at a landscape scale, helping to link up important areas and improve habitat for bats. All of this can help bat populations to grow and hopefully become more resilient to the future impacts of climate change.”

In the face of the climate and wider ecological emergency, it’s more important than ever to improve our understanding of UK wildlife species and the major threats they face. Upland habitats may be especially threatened by impacts from global warming, with increased risk of moorland fires, drying out of blanket bog wetlands, and changing or extreme weather patterns, all posing risks to bats, birds and the other iconic species of this fragile environment.

The monitoring work at Harden is expected to continue; the early results are encouraging but there is much to learn about how and why bats visit this particular site, and how they use moorland habitats more widely. This upland site can host future research and, by surveying bat activity year on year, conservationists can track population trends and monitor how bats are doing in the surrounding area.

The Harden study recorded no less than eight bat species using this remote moorland site. The headline findings and outcomes were:

Four bat species are swarming on the site in autumn: Natterer’s bat Myotis nattereri; Daubenton’s bat Myotis daubentonii; whiskered / Brandt’s bat Myotis mystacinus / brandtii; and, the brown long-eared bat Plecotus auritus. Bats use the sheltered and undisturbed mine shafts for winter hibernation too.

Bats quickly adapted to use the improved bat entrances to access the mine shafts, and were confirmed swarming at all four mine areas in 2023.

Pipistrelle and Noctule bats also feed over the heather moorlands in the summer months. The flowering shrubs attract an abundance of moths, midges, craneflies and other insects that bats love to eat.

Long-term monitoring has revealed how each bat species uses the moorland differently, and how much the activity levels can vary from month to month.

The research has demonstrated the importance that mines and other relics of human industry can have as breeding and sheltering areas for bats, particularly in a region with few natural caves. To help these mammals recover from historic population declines it’s crucial that key sites receive legal protection and are not lost.

The LWS designation puts this new bat site on the nature map. It will help guide local conservation policy, informing development of the Local Nature Recovery Strategy due for publication in April 2025.

Bats as a group provide an excellent indicator of the wider health of their ecosystem.  In the face of climate change, it’s more important than ever to improve our understanding of ecology and the threats to UK wildlife so that we can take the right action to protect habitats and slow or reverse population declines. Upland habitats may be especially under threat from global warming, with increased risk of moorland fires, drying out of blanket bog wetlands, and changing or extreme weather patterns all posing risks to bats, birds and the other iconic species of this fragile environment.