Bats suffer from not just an image problem but an awareness problem too – people rarely think about bats and when they do it is usually with negative connotations such as horror stories or that they are blind or ugly or might get caught in their hair. In real life of course bats are cute flying mice that play a vital role in the ecosystem and have a fascinating biology, one of the commonest (and smallest) species in Britain is the Pipistrelle – which is the focus of today’s post.

  • The Common Pipistrelle Pipistrellus pipistrellus can be found all over the UK and has a global range covering Europe, North Africa and south-western Asia. They can be found in a variety of habitats that have suitable roost sites and available prey.
  • It was only discovered in the 1990’s that the Pipistrelle was in fact two species; the new one being the Soprano Pipistrelle; they are very similar in appearance but P. pipistrellus echo-locates on a frequency of 45 kHz whereas P. pygmaeus uses 55 kHz.
  • The Pipistrelle can consume up to 3000 insects in one night’s foraging, the prey is largely made up of moths, flies, lacewings and beetles.
  • In appearance they have a ruddy-brown coat with a darker face and dark wings, they have a wingspan of up to 23 cm, are only 4.5 cm long and weigh just 8 grams.
  • In summer females group into maternity colonies where they will give birth to a single young in June or July, having mated in late summer last year.
  • The young feed on their mother’s milk at first until they can hunt for themselves after 6 weeks.
  • In the mating season males will defend a territory, centered around their roost site from which they will make song-flights, attracting females with special calls.
  • Pipistrelles are active from March to November, undergoing hibernation through the winter (though they do sometimes appear on the wing in winter if it is mild). They usually start hunting around 20 minutes after sunset.
  • In recent decades Pipistrelles have undergone large declines in their population (70% between 1978 & ’93) this is thought to be due to agricultural changes which have reduced prey abundance as well as loss of roosting/breeding sites as modern buildings are now hermetically sealed.