International Bat Night: Bats at Middleton Hall
The night of the 29th/30th August 2026 is International Bat Night. In the area of Middleton Hall, including the Site of Special Scientific Interest, about six different species of bat have been identified. They are known to roost in the attics of Middleton Hall, many of the buildings around the site and also in old trees around the grounds.
The first species known to be present in the area of Middleton Hall is the Common Pipistrelle (Pipistrellus pipistrellus). This is the most common species of bat found in Britain and roosts in both areas of woodland and the lofts and crevices of buildings. They are a very small bat with a head and body length of about 3.5-4.5cm, a wingspan of 20-23.5cm and weighing only about 5g. This species emerges about 20 minutes after sunset and has a fast and erratic twisting and jerky flight style. It is an edge specialist, hunting along the edges of woodland or tree avenues, hedgerows, grassland, farmland and gardens. It preys particularly on insects like mosquitos and midges as well as moths, lacewings, caddisflies and flies, which it catches and eats in flight. Their call has been described as being like a series of wet slaps or clicks that changes to something like a buzz when they get close to an insect and it ranges between 45-70kHz and peaks at 45kHz.
However, the surveys that identified the Common Pipistrelle at Middleton Hall were all undertaken before 1999, which was when testing proved it to actually be two very similar species. The second species is now called the Soprano Pipistrelle and it is known to prefer wetland habitats and thus there is a logical chance that it is also present at Middleton Hall. The main identifiable difference between the Common and Soprano Pipistrelle is that the Soprano has a call range of 55-80kHz that peaks at 55kHz.
Another species that has been recorded at Middleton Hall is the Brown Long-eared Bat (Plecotus auritus). This medium-sized species prefers to roost in quiet roof spaces or crevices in old buildings, especially outbuildings. It is unmistakable when seen because its roughly 3cm-long ears are only about one centimetre shorter than its body. Their flight style is described as slow and hovering. They emerge from roosts in the dark, about an hour after sunset, but they will also hunt during the day, particularly for moths. It flies amongst woodland and orchards to take insects such as earwigs, flies, beetles and spiders directly off the leaves or bark but can also catch insects off the ground. Its hearing is sensitive enough to be able to hear a moth in flight or even a ladybird walking on a leaf. Thus, unlike other species of bat, it does not need to use echolocation to find its prey and can rely on its hearing alone. This species is often called the “whispering bat” and has a very quiet call with a frequency range of 25-50kHz that peaks at 35kHz.
The third species that has been recorded at Middleton Hall is the Serotine (Cnephaeus serotinus). This species is a large bat with a wingspan of 32-38cm and dark, shaggy brown fur. It roosts in very old buildings. They emerge around dusk and are often one of the first bat species to appear in an evening. They fly relatively slowly in a highly manoeuvrable, fluttering flight style that is interspersed with brief glides or steep descents. In one night, they can travel up to 4 miles (there and back) to feeding areas and may feed in up to five different areas. It is an aerial hunter and its prey is normally insects such as moths, flies or dung beetles. Their call is a series of irregular sharp clicks that is often likened to the sound of smacking lips or hand-clapping and has a range of 15-65kHz that peaks at 25-30kHz.
The Noctule (Nyctalus noctula) has also been recorded at Middleton Hall. This is also a large bat, one of the largest in Britain, with a wingspan of up to 40cm. It roosts in old trees in either rot holes or old woodpecker nests. They forage predominately at dusk and dawn and fly high and fast, reaching up to 37mph, in open sky, well above the tree canopy level, before suddenly vertically diving to catch beetles, moths or winged ants. Their call has a distinctive “chip chop” sound and has a range of 20-45kHz that peaks at 25kHz.
The fifth species that has been recorded at Middleton Hall is Daubenton’s Bat (Myotis daubentonii). This species is a wetland specialist often known as the “water bat”. It normally roosts close to water sources, often in tunnels and caves or under bridges and occasionally in old stone moated buildings. It has a highly specialised hunting style in that it flies just inches over the water’s surface and uses its large hairy feet or tail membrane to take insects off the surface of the water. It emerges normally at twilight and its prey is normally midges, small flies, mayflies and moths. Their call is a rapid clicking or purring sound that has been described as similar to rapid machine gun fire and has a range of 35-85kHz that peaks at 45-50kHz.
The final species is challenging due to the difficulty of identifying it. It is the Whiskered/Brandt’s Bat (Myotis mystacinus/Myotis Brandtii). These two are sister species and were only distinguished from each other in 1970. To complicate it further, in 2001 another sister species, the Alcathoe Bat (Myotis alcathoe), was identified. The Alcathoe was only first confirmed as present in Britain in 2010. These three species are extremely difficult to tell apart. All of them are small bats with dark brown-golden fur on their backs, a greyish underside and a hairy face. They all emerge about half an hour after sunset and fly fast and low. They all prefer areas of deciduous or mixed woodland, hedgerow or any vegetation close to water, although the Whiskered Bat can be found in more diverse habitats including meadowland and urban areas. Furthermore, they all have a call that sounds like a dry rapid clicking that peaks at about 45kHz, which can also be confused with the Pipistrelles call. The echolocation range is slightly different for the three species with the Whiskered having a range of 32-89kHz, Brandt’s 33-89kHz and the Alcathoe of 43-120kHz.
Further Reading: “UK Bats”, Bat Conservation Trust, https://www.bats.org.uk/about-bats/what-are-bats/uk-bats
Author - Debbie Jordan, Middleton Hall Volunteer.
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