By Cori Birkin
April 2025

There’s a stillness that settles over the water at twilight. Our senses heighten in the hush of the approaching night. A tawny owl follows unseen creatures with its watchful gaze from a branch across the way. Above us, swooping and flitting in their insect-catching dance, fly the bats. 

 

I wonder what you already know and think of bats? 

 

Growing up in a semi-rural Scottish village, down a dead-end street with no lampposts, it was a familiar sight to watch them zapping down the road and around my house. My siblings and I were entranced. 

 

In the media, bats could be superheroes - saving the city, or villainous - alternate forms of killer vampires, creatures of darkness. I was fed stories of vampire bats as big as basketballs that really would drink human blood should they get into your room at night. They held quite a distinctive presence in my mind. 

 

However, it was whilst living in a sustainable housing co-operative in Shropshire that I first became fully aware of the wonder that these mysterious nocturnal creatures hold. 

 

This particular piece of land can only be described as a haven. Nestled within England’s traditional farming landscape, it has sprouted under ideals of reciprocity, sharing and sustainability since its acquisition in the 70’s. The residents see themselves as stewards of the land, growing enough over their 26 acres to remain mostly self-sufficient via organic, diversity-enhancing land practices only. 

 

A striking factor of this place is the biodiversity it houses alongside the people – rich soils teeming with life, and loud, lively birdsong filtering down from trees, rooftops, and hedgerows. Over last year’s summer season, I watched house martins build mud-cup nests along the roof's edge, buzzards circling overhead, and two resident barn owls glide out across the bottom field most evenings (catching food for their three owlets within the nest box), before hundreds of bats (pipistrelles and noctules) would emerge and swoop around the house. It became ever-more evident during my time here just how stark the contrast can be between land-management practices in supporting this. A short walk beyond the bounds of this home lay heavy monoculture fields - one species only. The birdsong dimmed, the buzzing of insects a whisper, my eyes filled with one productive hum. But stepping back to our land - a cacophony! An orchestra of tangled weeds, wildflower meadows, insects, birds, and - bats! 

 

One dusky summer’s evening, our survey of a roost on the side of the house counted 374 soprano pipistrelle bats living in this one roost alone. A wonder to me, as I learnt that due to their high metabolic rates each bat eats up to 30% of its body weight in insects each night - or, for these pips, around 3,000 insects each per night. A quick bit of maths revealed that in total our winged neighbours must be feasting on over a million insects each night! 

 

The richness was indeed notable to the point that, on multiple occasions, I had bats fly into my room (picture a big old countryside house with maybe just a few holes in the roofing) in the middle of the night, which I then had to chase around and out with a blanket. With memories stirred up of my childhood stories of vampire bats, it is safe to say that this was maybe not my most awe-inspiring experience. 

 

It was here also, that I learnt of the presence of Noctule bats - the UK’s largest species. With a call at a low enough frequency that young ears can still hear (most bats calls are above our hearing range), a fellow 21 year-old and I would lie in the evening grass and point out their passing overhead to the rest of the group. 

 

These bats serve as an indication of something bigger, the space to support other species in their insect-feasting niches, the sign of a web of life well-nourished. 

 

This diversity is not only a testament to the beautiful potential for biodiversity still homed within the British countryside but also the care and energy put in by the dwellers of this land over the years to support their fellow residents as much as they can. The gardens and growing fields have had a lot of trial and error over the years, with legacies of previous residents scattered around the land. Efforts to be as self-sufficient and sustainable as possible have led to an evolving approach that makes use of the land’s niches and supports the other species there. It’s proof of a practice that works to allow humans and nature to live side-by-side, with enough nourishment and space for each. 

 

Now, in St Andrews, as bats emerge once again from their winter hibernation, the Biodiversity Literacy VIP resumes our bat walks across the town. Wandering along the Kinness burn, we catch the calls of soprano and common pipistrelles on our detectors and look upwards to see them flitting to-and-fro above. They’re not the only creatures out at dusk, and it’s a great chance to seek out some of the lesser-spotted crepuscular (dawn and dusk) and nocturnal (night-time) mammals like otter and badger, and nocturnal bird species too. 

 

Enough about me, what about the bats? 

 

In total, there are 18 species of bats within the UK, accounting for almost a third of our total mammals. All are protected under the Wildlife and Countryside Act 1981 with increasing threats of habitat loss, light pollution, insect declines and roost disturbance. 

They roost in a variety of habitats depending on species and time of year, always using structures already available. This can include hollow trees, caves, bridges, buildings, hanging tiles, underground, and in roof spaces. During Summer, female bats gather in maternity roosts to give birth, whilst in Winter, bats sleep in hibernation roosts. 

Hunting strategies vary by species but include: 

• Aerial hawking: Catching insects mid-air (e.g. Pipistrelles) 

• Gleaning: Picking prey off surfaces (e.g. Long-eared Bats) 

• Trawling: Skimming water for insects (e.g. Daubenton’s) 

Here in St Andrews, we have recorded: