Bat surveys are an essential part of the work we do to help biodiversity and provide bats with great habitats in Dorset's woodlands. You can help support this work by donating to the Woodland Recovery Appeal today.

Woodlands are key to supporting the majority of our UK bat species in some way. For a number of species, it is their primary habitat, supporting all stages of life – providing foraging, roosting and breeding opportunities. For other bat species, woodlands, trees and hedgerows are the highways of the landscape. As such, fragmentation of woodlands has huge impacts for bats. By reconnecting these isolated pockets, through natural regeneration or planting trees, we can help to provide safer corridors for bats to navigate the landscape. 

Our task tonight is to understand more about which species are using the wood and how. We load ourselves up with kit, as well as the necessary snacks and flasks of coffee. Then we begin the 10-minute tramp to base camp through sodden vegetation. 

Woodland provides the ideal habitat for our bat species. The canopy and understory is alive with insect life of all kinds to sate the appetite of a hungry bat. Bats can eat thousands of insects in one night, fuelling their high energy demands. They not only catch them from the air but will pick them from vegetation and even crawl on the floor for them! The cover of the canopy helps conceal the bats and buffer them from environmental conditions outside the wood.  

We set up base camp, then split up to set up our equipment. We are using a harp trap that will catch bats as they fly around the woodland. Once harmlessly caught, we can examine the bats, determine the species, their sex, age, and breeding status. They are then freed to go about the rest of their evening.

The excitement comes every time a bat is found in the trap; what will it be? Will we discover something new to the site?  

As we approach the trap we see something dark nestled in the trap bag. Our excitement heightens – a barbastelle bat! They are elusive, a great find for the survey and a first for the site. This one is a female born this year, with shiny wings, so hasn’t bred yet. They are rare, using predominantly woodland and feeding mainly on moths. They use a cunning trick to outwit their prey: they reduce the intensity of their echolocation call as they approach the moth. The moth still thinks it’s too far away to eat them, and by the time they realise, it’s too late!  

Woodland management is important for barbastelles as they roost in small crevices, often just behind flaking bark, so standing deadwood is key for them. We can create this to help things along, or it will come naturally to a woodland over time. We may find that, with the prevalence of ash dieback across woodlands, barbastelles could benefit from this in the short term. But in the longer term, ash dieback could be disastrous for woodland bat species. This will especially be the case in woodlands with canopies dominated by ash where the ecosystems stand to change dramatically. 

While we wait for the next trap check, the nighttime woodland soundscape soothes the tired mind. The distant call of a tawny owl pierces the silence, the guttural grunt of the fallow deer as they begin their rut sends tingles down your spine, the buzz of a hornet has everyone scrambling to turn off lights. If we’re lucky, we spot the luminescence of a glow worm. 

Our woodlands and the wildlife they support face an uncertain future, as with a changing climate, what they have come to know could be altered forever. The extremes of climate change will undoubtedly mean droughts, floods and new pathogens and diseases for woodlands to withstand. The resilience of our woodlands will be tested, and we will need them to be diverse in species and range for their best chance at survival. 

We drag our tired selves back towards the vehicle, contemplating our finds – barbastelle, Natterers, Bechstein’s and brown long-eared bats - a good night. Let’s hope we can ensure a safe and secure future for them here in Dorset – every donation to the Woodland Recovery Appeal brings us closer to achieving that goal.