Saving Dorset’s bats

Greater Horseshoe bat (Rhinolophus ferrumequinum) hibernating in cave

Nothing quite ruins a Summer’s barbecue than a swarm of pesky mosquitoes. But help may be at hand in an unexpected form – bats.

Forget burgers and beer, the crucial ingredient for a successful al fresco party is the bat. Seriously!  Without the voracious dusk appetite of these much-maligned creatures of the night, we’d all be eaten alive by mosquitoes before a crisp so much as touched our lips. 

If even the smallest chiroptera (to give them their scientific name) in Britain can eat up to 3,000 insects per night, think of what Purbeck’s rare Greater Horseshoe Bat, with its lifespan of thirty years and wingspan of 36cm, must get through. 

Bat numbers down

Once widespread, the UK population of the Greater Horseshoe is now put at about 6,500, with only 200 breeding females in Dorset. 

National Trust ecologist Michelle Brown says: “Bats were practising speed-dating long before we were, and when the babies come along, the females run an efficient crèche too. Not that you would choose to enter one without a face mask to shield you from the reek. We creep in with a single red light torch to try and count the babies but we don’t hang around!”  

Bats hibernate in quarries and mines

They hibernate over winter in the old stone quarries and underground mine shafts along the South Purbeck coast. 

Sea quarries like Dancing Ledge are a feature of the south Purbeck coast
Dancing Ledge, Dorset
Sea quarries like Dancing Ledge are a feature of the south Purbeck coast

One of the remaining mysteries is why, between hibernation and breeding, they set up interim roosts like the one at Boar Mill near Corfe Castle. It’s possibly to conserve calories before flying to the maternity roost. Purbeck’s Greater Horseshoes currently travel to Blandford, 30 kilometres away. 

“Ideally, we’d like them closer to home so we’ve been eyeing up old stone buildings and cellars of manor houses on their behalf. We’re even considering building a bespoke roost on an old flight route and sprinkling it with some of their droppings,” says Michelle.  

Learning to love bats

Bat conservation in Purbeck is very much a joint effort with multiple land owners, other conservation groups and scientists all working to the same goal. 

The rest of us need to find the love too. Whether our new found admiration is fuelled by the desire for a mosquito free barbecue or a healthy wilderness, well, does it really matter? We all win in the end. 
Additional facts:

•    Intensive farming methods led to the disappearance of the insects that bats feed exclusively on
•    Greater Horseshoes don’t start breeding until they are four 
•    Bats navigate across wide areas of countryside at night following hedgerows and woodland edges 
•    There are more than 1300 bat species in the world, only three of which are vampire bats  
•    The fear of bats is known as Chiroptophobia 
•    Bats are not blind – they can see as well as we can at night
•    Bats are not flying mice and are more closely related to humans, their wing structure being the same as the human hand but with longer fingers and a membrane of skin.   
•    Chiroptera comes from the Latin for ‘hand’ and the Greek for ‘wing’