The Common pipistrelle is a very small species of bat whose very large range extends across most of Europe, North Africa, southwestern Asia, and may extend into Korea. It is one of the most common bat species in the British Isles. This microbat is common in woodland and farmland but is also found in towns, where the females roost in lofts and buildings when rearing young.
Common pipistrelles have a Palearctic distribution. They occur in the British Isles, southern Scandinavia, much of Continental Europe, and parts of Northwest Africa. They are also found in India, China, and Myanmar in Asia. Common pipistrelles occur in woodlands, shrubland, grasslands, near wetlands, and in agricultural and urban areas.
Common pipistrelles are nocturnal gregarious creatures that live in large colonies. They roost during the day in trees or in buildings and right before sunset head to hunt their prey. They prefer to forage along woodland edges and along isolated tree lines catching their favorite insect prey such as mosquitoes, midges, and gnats. In order to locate their prey pipistrelles use echolocation; the frequencies used for echolocation lie between 45 and 76 kHz and have an average duration of 5.6 ms. With the start of the cold, around mid-October Common pipistrelles become less active and prepare for winter hibernation which lasts until spring. They usually choose warm and sheltered places for hibernation in buildings, hollow trees, deep in rock crevices, or bat boxes.
Common pipistrelles mate in the fall, just before hibernation but females become pregnant in May and June due to their ability to delay fertilization. Males attract females by creating courtship territories approximately 200 m (660 ft) in diameter; these territories are maintained from mid-July through the end of October, with the peak of activity in September. Courtship territories are usually located in the vicinity of popular winter roosts. Males will patrol these territories while "singing" to attract the attention of females as they travel to winter roosts. Male courtship territories are densely-packed and offer females choice akin to a lek mating system. After hibernation pregnant females form large aggregations in roosts, called maternity colonies. These colonies can consist of dozens or even hundreds of individuals. Gestation lasts around 50 days and parturition usually occurs in June. Females typically give birth to a single pup, though in some populations, twins are regularly produced. The pups are born altricial; they are naked, blind, and helpless. The females nurse their young within 3 weeks at which time pups are able to fly to and become independent. Females reach reproductive maturity at one year of age while males start to breed when they are 2 years old.
The main threat to Common pipistrelles is the loss of foraging habitat due to agriculture intensification. They also suffer from timber treatment, building renovation and construction, pollution, the use of pesticides, and collisions with auto transport.
According to IUCN, the Common pipistrelle is widespread throughout its range but no overall population estimate is available. Currently, this species is classified as Least Concern (LC) on the IUCN Red List and its numbers today are stable.