The Effect of Urban Growth on Bats across the UK

Summer Elsie discusses the difficulties bats are facing and the behavioural adaptations permitting their survival in the modern world.

A black bat. Image Credit: HitchHike on Pexels.

Bats are one of the most common creatures you’ll see on a nightly walk, often swooping down below streetlights in search of food, shortly before retreating back to shelter for rest. Despite their common appearances across the country, they remain one of the most misunderstood and feared mammals at a global scale due to their negative representations within our media.

With 18 species of bats in the UK, sightings are common if you know what you’re looking for. However, urban growth is a significant process across the UK within the current years, becoming a driving force in land-use change and deforestation to support the ever-increasing population. Despite its many benefits for humans, allowing us to go to a shop within five minutes of our home or giving us shorter drives to our destinations, this constant alteration of land-use is significantly damaging to many mammals at a global scale, specifically our beloved flying mammals: bats.           

A common pipistrelle. Left image: Gilen San Martin on Wikimedia Commons; Right image: Françoise Chanut on Wikimedia Commons. 

There are many bats across the UK, especially Barbastelles and Pipistrelles, members of the Chiroptera taxon, that are severely struggling due to our constant changes in land use and the proliferation of our technology. They’re losing their habitats, their safety and their diets. At a global scale, over 40% of bats are now listed as threatened by extinction due to their significant decline in population size over the 20th century. This is due to many anthropogenic factors, specifically, the alterations in their diets and hunting activities due to mass deforestation.

Many bats are now significantly discouraged from their hunting and foraging due to noise and light pollution, causing a decline in insect biomass. Many bats are apprehensive about flying across roads to forestry in search of insects due to the constant loud noises. Thus, many bats across the world are experiencing malnutrition and their reproduction rates are declining as they can’t afford to feed themselves or their young. 

Luckily, not all bats are suffering due to the effects of urbanisation, while their eating habits have been disrupted, some bats including common and soprano pipistrelles have adapted to the change in land-use across the UK. So many will now hang around streetlights and shop fronts at dusk as they’ve acknowledged that insects such as moths are attracted to these brighter areas, allowing them to successfully forage for prey using anthropogenic variables. Barbastelles, despite being extremely rare across the UK, have also been known to adapt to human intervention, by nesting in our buildings, such as attics or abandoned locations for shelter and their own safe space. From my own experiences using a heterodyne (bat box) I have detected a common pipistrelles frequency outside an old subway building along Falmouth high-street! Thus, many bats are now beginning to adjust and adapt to our intervention, despite the lack of forestry.

A Barbastelle. Image credit: C. Robillier on Wikimedia Commons.

However, as urban growth continues across the country, bats are still suffering due to predation and the dangers of human technology. They are now major targets to our beloved feline friends, often being caught and brought into our homes heavily injured. These attacks are now being tracked by ‘Trust BC: threats to bats’ as cats do play a major role in the declining bat populations at a national scale. Another significant factor in the danger of bats would be the proliferation of our transport systems. Bats are often a victim to roadkill and severe injuries due to collision with cars caused by disorientation from both the lights and noise. 

These impacts on bats due to our urban intervention raises many questions like, why should we care? But bats provide a significant amount of help and resources for us, for example, bats aid agriculture across the world; acting as a natural pest control for the population by feeding on insects, keeping them away from crops and herbs. The loss of bats would cause a severe decline in the agricultural economic sector, predicted to be up to $53billion a year! For this reason, we simply cannot afford to lose these vital mammals due to urban growth and development. 

About the author: Summer Elsie is a Zoology student under the University of Exeter who wishes to specialise in sensory ecology within her future careers, specifically the welfare of bats. You can follow her on Instagram at @sum_elsie.