Soprano pipistrelle

GB: Least concern

England: Least concern

Scotland: Least concern

Wales: Least concern

Global: Least concern

Head & body length: 35mm - 45mm

Forearm length: 29mm - 34mm

Wingspan: 190mm - 230mm

Weight: 3g - 8g

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

The two commonest pipistrelle species found in the UK, the common pipistrelle 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.

Soprano pipistrelles usually feed in wetland habitats, for example over lakes and rivers, and also around woodland edge, tree lines or hedgerows, and in suburban gardens and parks.

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’. Soprano pipistrelles appear to be more selective in their habitat use than the more generalist common pipistrelle.

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

This species also roosts in tree holes and crevices, and also in bat boxes. Summer roosts of soprano pipistrelle support colonies of an average size of 200 bats, but they can be even larger with numbers reaching several hundred to over a thousand bats.

In winter soprano 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.

Soprano pipistrelle feeds mainly on small flies, particularly midges and mosquitoes that are associated with water.

During the summer, soprano 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.

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

Sounds produced by soprano 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 of soprano pipistrelle can be picked up between about 55 and 80kHz. 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 55kHz, the peak intensity of the call.

The soprano pipistrelle is widely distributed across the UK, with the exception of the very northern parts of Scotland. Along with the common pipistrelle it is one of Britain’s commonest bat species.

Populations of pipistrelles have historically declined. This is at least partly as a result of modern agricultural practices. Their reliance on buildings for roosting makes them vulnerable to building renovations, exclusion and toxic remedial timber treatment chemicals.