Common pipistrelle

GB: Least concern

England: Least concern

Scotland: Least concern

Wales: Least concern

Global: Least concern

Head & body length: 35mm - 45mm

Forearm length: 30mm - 35mm

Wingspan: 200mm-235mm

Weight: 3g - 8g

Colour: Medium to dark brown. Face and around the eyes usually dark.

Common pipistrelle appear fast and jerky in flight as they dodge about pursuing small insects which the bats catch and eat on the wing.

The two commonest pipistrelle species found in the UK, the common and soprano pipistrelle, were only identified as separate species in the 1990s. The two species look very similar and often the easiest way to tell them apart is from the frequency of their echolocation calls.

Common pipistrelles feed in a wide range of habitats comprising woodland, hedgerows, grassland, farmland, suburban and also urban areas. They generally emerge from their roost around 20 minutes after sunset and fly 2-10m above ground level searching for their insect prey, which they catch and eat on the wing by ‘aerial hawking’.

Summer roosts of common pipistrelles are usually found in crevices around the outside of newer buildings. They can be found behind hanging tiles, soffit and barge or eaves boarding, between roofing felt and roof tiles or in cavity walls.

Common pipistrelle is also known to roost in tree holes and crevices, and also in bat boxes. Summer roosts support smaller colonies than soprano pipistrelles, with numbers averaging around 75 bats. Common pipistrelle maternity colonies are more likely to move between roost sites than those of soprano pipistrelles.

In winter, common pipistrelles are found singly or in small numbers in crevices of buildings and trees, and also in bat boxes. They are often found in relatively exposed locations and rarely underground.

Common pipistrelle feeds mainly on a wide range of small flies as well as the aquatic midges and mosquitos.

During the summer, common pipistrelle females form maternity colonies where they give birth to a single young in June or early July. For three or four weeks the young are fed solely on their mother’s milk. After about four weeks the young are able to fly and at six weeks they are able to forage for themselves.

Male bats usually roost singly or in small groups through the summer months. During the main mating period from July to early September, common pipistrelle males defend individual territories as mating roosts. They attract females by making repeated ‘songflights’ around their roost and singing social calls.

Sounds produced by common pipistrelles are above the range of human hearing with the exception of social calls that may be heard by children and some adults with good hearing. With a bat detector (heterodyne) the echolocation calls can be picked up between about 45 and 70kHz.

The calls sound like a series of clicks towards the top of this range, turning into ‘wetter’ slaps with the deepest sounding slap being heard at about 45kHz, the peak intensity of the call.

The common pipistrelle is widely distributed across the UK and its distribution appears to extend further north than that of soprano pipistrelle.

Populations of pipistrelles have declined dramatically in the last few decades. This is at least partly as a result of modern agricultural practices, although common pipistrelle populations have started showing signs of recovery in recent years. Their reliance on buildings for roosting makes them vulnerable to building renovations, exclusion and toxic remedial timber treatment chemicals.