About Our Biggest Bats
Scotland is home to a variety of bat species, most of them small and often seen only as quick silhouettes at dusk. But among them are several larger species whose size, flight style, and behaviour make them stand out. Although these bats are still lightweight and delicate, they are noticeably bigger than pipistrelles and show different patterns of movement and feeding.
This blog introduces the three biggest bat species recorded in Scotland: the noctule, the Leisler’s bat, and the Daubenton’s bat.
Noctule: one of the UK’s largest bats
The noctule is among the biggest bats found in Britain. It has long, narrow wings designed for fast, high flight and is known for emerging early in the evening, sometimes even before sunset. Noctules hunt beetles and other large insects in open spaces, flying well above tree level.
In Scotland, noctules are uncommon but present, with records mainly from the central and eastern parts of the country. Their size and early flight time make them easier to spot than many other species, although they are still rarely encountered by most people.
Noctules typically roost in tree cavities, including old woodpecker holes or natural hollows. Because they depend on mature trees, they benefit from landscapes that retain older woodland features.
Leisler’s bat: a high-flying, wide-ranging species
Leisler’s bats are slightly smaller than noctules but remain one of the largest species seen in Scotland. They have a powerful flight and often travel across large areas in a single evening. Like noctules, they tend to fly high, so they are not always recorded by observers at ground level.
Leisler’s bats roost in tree cavities and sometimes in buildings. In Scotland, they are considered uncommon, but sightings do occur, often in connection with warm weather and long-distance movements. Some individuals are thought to travel between regions in response to seasonal changes.
Their strong flight and broad foraging range mean they can use open landscapes, parkland, and edges of woodland, making them quite different in behaviour from smaller bats that need sheltered feeding areas.
Daubenton’s bat: the specialist of water
Daubenton’s bats are not as large as noctules or Leisler’s bats, but among Scotland’s regularly encountered species they are one of the bigger and more recognisable types. Their wings and body size are slightly larger than pipistrelles, and their feeding behaviour makes them easy to identify.
Often called the “water bat”, Daubenton’s bats forage low over the surface of rivers, burns, canals, and lochs, catching insects with their feet or tail membrane. They fly smoothly and level with the water, making them one of the easiest bats to observe closely.
Daubenton’s roosts are commonly found in bridges, stone structures, trees, and buildings near water. Their reliance on healthy waterbodies makes them a good indicator of local environmental conditions.
Why size matters in bat ecology
Larger bats tend to:
fly higher and faster
use bigger or more open landscapes
depend more on mature trees or large structures
feed on larger insects
These differences affect how they respond to lighting, habitat change, and weather. Understanding species-specific behaviour helps ecologists protect bats while supporting responsible development and land management.
Seeing Scotland’s biggest bats
While most people encounter pipistrelles, occasional sightings of noctules, Leisler’s bats, or Daubenton’s bats offer a special glimpse into Scotland’s wider bat diversity. Each species plays a unique role in the landscape, and all contribute to a healthy and balanced ecosystem.
References
Bat Conservation Trust 2023. Bats in Britain: Species Profiles. Bat Conservation Trust, London.
NatureScot 2020. Bats: Licensing and Guidance. NatureScot, Inverness.
Russ, J. 2012. British Bat Calls: A Guide to Species Identification. Pelagic Publishing, Exeter.