(Nyctalus noctula)
The Noctule is one of Britain's largest bats, with rich golden-brown fur and long, narrow wings built for fast flight. Often appearing before other bats have emerged, it hunts high above gardens, parks and woodland edges, chasing beetles, moths and other flying insects through the evening sky. Its size, speed and direct flight make it one of the most exciting bats to spot on a summer evening.
Meet the Noctule Bat
If you look up just before sunset on a warm summer evening, you might see what looks like a swift cutting across the sky. It flies quickly and purposefully, sometimes climbing high above the trees before making a sudden, steep dive.
Look a little closer and you may be watching a Noctule.
Unlike smaller bats that often flit close to buildings, hedges or garden borders, Noctules are powerful open-air hunters. They can emerge while there is still light in the sky, making them a particularly rewarding species for anyone who enjoys watching wildlife without having to stay up late.
They are also a reminder that a garden's wildlife story extends well beyond its flowerbeds. The insects rising from lawns, meadows, ponds and woodland edges can attract bats that travel considerable distances to feed.
How to identify a Noctule Bat
The Noctule is a large, robust bat with sleek golden or reddish-brown fur, darker wings and a broad, rounded face. Its ears are relatively short and broad, with a distinctive mushroom-shaped tragus, the small projection of skin inside the ear.
At a glance:
- Head and body length: around 6–8.2cm
- Wingspan: 32–40cm
- Weight: 18–40g
- Fur: Golden, chestnut or reddish brown, sometimes darker after moulting
- Wings: Long, narrow and pointed
- Most useful field clue: Fast, straight flight high above trees, often with sudden dives while hunting
The Noctule is often described as Britain's largest bat species. Its size can be difficult to judge against the open sky, but its powerful flight and broad silhouette can make it stand out once you know what to look for.
How is it different from other bats?
The Noctule is sometimes mistaken for a swift because both can fly quickly through open air, particularly at a distance. Swifts have a distinctive swept-back, scythe-like wing shape, while a Noctule's flight often includes repeated steep dives as it chases insects.
Leisler's bat is another species that can be confused with the Noctule. It is smaller, but judging size against a dark sky is not easy, and the two can share similar habitats and flight patterns. Serotine bats may also produce calls with overlapping characteristics.
A bat detector can help. Noctule calls are relatively low-pitched for bats, with much of their energy around 25 kHz. Some people, particularly children and younger listeners, may hear parts of their calls without a detector. On a suitable detector setting, the calls can have a distinctive “chip-chop” quality, although experienced interpretation is needed to distinguish similar species confidently.
Where do Noctules live?
Noctules are found across much of England and Wales, extending into south-west Scotland, but they are absent from Ireland. They are associated with wooded landscapes, open countryside, pasture, parkland and wetlands, where flying insects are plentiful.
Their reliance on trees is especially important. Noctules mainly roost in cavities in mature trees, including old woodpecker holes and natural hollows caused by decay. These spaces provide shelter for resting, breeding and hibernation.
Unlike some bats that frequently roost in houses, Noctules are rarely found in buildings in Britain. They can use bat boxes, but a network of suitable tree cavities is particularly valuable because colonies may change roosts regularly, especially during the breeding season.
A Noctule feeding over your garden may not be roosting nearby. Individuals can travel several kilometres between their roost and feeding areas, sometimes covering more than 10km. This means that gardens, parks and allotments can form part of a much wider feeding landscape.
When do Noctules emerge?
Noctules are often among the first British bats to appear in the evening, sometimes emerging before sunset. This early activity makes them easier to observe than species that emerge in near darkness.
In spring and summer, try watching the sky above tree canopies, open lawns, meadows or a large pond as daylight fades. Noctules often fly high and fast, covering ground with a direct flight before suddenly diving or turning to catch prey.
They may return to productive feeding areas repeatedly, so it is worth staying in one spot for a while rather than moving around in search of them. On a good evening, you may see several passes across the same stretch of sky.
What do Noctules eat?
Noctules are insect hunters, catching most of their prey on the wing. Their diet changes with the seasons and the insects available.
In spring, they feed on smaller insects such as midges and mayflies, as well as winged ants. Later in the year, larger prey becomes important, including moths and beetles such as chafers and dung beetles.
Their fast flight allows them to hunt in open air, often above the tree canopy or over grassland and water. They may also feed around streetlights, where flying insects gather, although artificial lighting can disrupt other bats and should not be considered a substitute for naturally dark feeding routes.
For garden wildlife lovers, the lesson is simple: a garden that supports insects contributes to a much larger food web. Leaving some areas of grass to grow, planting nectar-rich flowers and reducing pesticide use can help sustain the insects that bats depend on.
How do Noctules breed?
Noctules have an unusual breeding routine. In late summer, males establish mating roosts, usually in tree holes, and defend them against other males. They use shrill calls and scent to attract females, which may visit a male's roost for mating.
During spring, mixed-sex groups form before females gather into maternity colonies. These colonies use tree cavities and may switch between several roosts as the season progresses.
Females usually give birth to a single pup in late June or July, although twins are occasionally recorded. Mothers leave their young together in a crèche while they go out to feed, returning to nurse them. The young develop quickly and are generally able to fly and forage independently by around six weeks old.
Because maternity colonies may move between trees, protecting just one occupied cavity is not always enough. A landscape with several suitable mature trees can provide alternative roosts as the colony's needs change.
Where do Noctules go in winter?
As insects become scarce, Noctules spend much of the winter hibernating. They commonly use tree cavities and may also shelter in rock fissures, buildings or bat boxes.
Unlike a bat that hibernates deep underground, a Noctule may spend winter in a hollow tree exposed to colder conditions. It can tolerate low temperatures, and on mild winter nights some individuals may become active and feed if insects are available.
Hibernation helps bats conserve energy when food is limited. Disturbing a roost can cause them to wake and use precious reserves, so tree cavities and other potential roost sites should always be treated with care.
Noctule population and conservation in the UK
The Noctule is currently classified as Least Concern in Great Britain, and it remains widespread across much of England and Wales. However, this status does not mean that every local population is secure or that its habitat needs are being met.
Noctules depend heavily on mature trees with suitable cavities, including standing deadwood and trees with old woodpecker holes. The removal of these features during woodland management, along roadsides or in parks can reduce the number of available roosts.
Changes to farmland also matter. The loss of permanent pasture, hedgerows and insect-rich woodland edges can reduce feeding opportunities, while pesticide use can affect the abundance of their prey. Noctules are also vulnerable to collisions with wind turbines, although the effect on populations remains uncertain.
Protecting mature trees, retaining suitable deadwood where safe, and maintaining connected habitats rich in insects all help support this remarkable bat.
How can you help Noctules?
You don't need a large garden or woodland to make a useful contribution. Think about how your outdoor space fits into the wider landscape.
- Grow and protect insect life. Plant a variety of flowers, avoid pesticides and leave some areas of grass to grow longer.
- Keep mature trees where it is safe. Cavities and natural hollows can provide vital roosting spaces. Seek expert advice before work on a tree that may contain bats.
- Retain hedges and wildlife corridors. These support insects and connect feeding habitats across the landscape.
- Keep some areas dark. Avoid unnecessary lighting around trees, hedgerows and potential roosts, particularly where bats commute or feed.
- Watch the sky at dusk. Choose a safe, open viewing spot and allow your eyes time to adjust as the light fades.
Would a bat box help?
Noctules have been recorded using bat boxes, especially where suitable tree cavities are scarce. A box can offer an additional roosting opportunity, but it cannot replace the value of mature trees with natural holes.
Choose a well-made, untreated box designed for bats and position it high on a suitable tree or building, with a clear flight path and minimal disturbance. Good choices include Schwegler 2FN Special Bat Box and the Kent Bat Box. If possible, provide more than one box with different aspects so that bats have a choice of conditions. There is no guarantee that they will use it, and it may take time for bats to discover a new roost.
Noctule Bat FAQ's
Are Noctules the biggest bats in the UK?
The Noctule is one of Britain's largest bat species and is generally regarded as the largest regularly occurring species. The exceptionally rare Greater Mouse-eared Bat has also been recorded in Britain.
Can I see a Noctule in my garden?
Yes. Noctules can hunt over gardens, parks and open spaces, particularly where there are plenty of flying insects nearby. You are most likely to spot one high in the sky around sunset, rather than close to a feeder or garden wall.
Why do Noctules come out before other bats?
Noctules are adapted to hunting flying insects in open air and often begin feeding while there is still some daylight. Their early emergence makes them one of the easiest British bats to watch without staying out late.
Do Noctules live in houses?
They are rarely found in buildings in Britain. They mainly roost in tree holes, including old woodpecker cavities and natural hollows, and have also been recorded in bat boxes.
Are Noctules protected?
Yes. All UK bat species and their roosts are legally protected. It is an offence to harm bats or unlawfully damage or disturb their roosts. If you suspect bats are using a tree or building where work is planned, seek advice from a qualified bat specialist before proceeding.
