Nathusius’s Pipistrelle

Identification

Nathusius's pipistrelle is a small bat easily confused with the common pipistrelle, though closer inspection reveals several distinguishing features. It measures 46–55 mm in head and body length, with a wingspan of 220–250 mm and weighing just 6–15.5 grams. The forearm is 32–40 mm long, and the fifth finger exceeds 43 mm. Compared to its common relative, this species is noticeably larger with broader wings, and its fur is longer and more irregularly colored. The upperparts display a medium-dark reddish-brown tone, often with paler tips, while the underparts are pale brown. The face, ears, wings, and tail are distinctly dark, providing useful field marks for identification.

Range & Habitat

This highly migratory species is widely distributed across Europe, ranging from Western Europe eastward to the Ural Mountains, Turkey, and the Caucasus. Individuals from northern and eastern populations migrate southwest to winter grounds, making their presence highly seasonal in many areas. Nathusius's pipistrelle is generally more common in Central and Eastern Europe, while in western regions it historically appeared mainly as a rare winter visitor. However, recent decades have brought significant range changes: new breeding colonies have been discovered across Western Europe, and the species is now known to breed at several sites in Britain and Ireland, where it was previously considered merely a vagrant.

The species favors parkland and light woodland habitats, with a strong preference for areas near water. It relies on hollow trees for breeding colonies, though it has adapted well to bat boxes and occasionally roosts in buildings. Threats include the loss of hollow trees and toxic timber treatments in structures, but legal protection and successful breeding in artificial roosts have helped stabilize populations in many countries.

Behaviour & Diet

Nathusius's pipistrelle is an early emerger, taking to the wing to hunt before many other bat species. It flies in characteristically straight lines with rapid, deep wingbeats, typically hunting at heights of 3 to 15 metres above the ground. Its diet consists primarily of small to medium-sized flying insects, with chironomid midges forming a particularly important food source. Mating occurs from July to early September, when males establish territories and gather harems of females. Females gather at nursery roosts in spring, where each gives birth to two young per season.

Best Time & Places to See It

Nathusius's pipistrelle is most reliably encountered in Central and Eastern Europe, where populations are most established. In Western Europe, winter months offer the best opportunity to encounter this migratory species. Recent range expansion means that Britain and Ireland now support breeding populations, making spring and summer viable seasons for observation in these regions. Look for activity over water and in open parkland or light woodland habitats, particularly during the early evening hours when this species emerges to hunt.

Photography Tips

Photographing Nathusius's pipistrelle requires specialized equipment for capturing fast-moving subjects in low light. High-speed flash and fast shutter speeds are essential to freeze the rapid wingbeats and straight-line flight pattern characteristic of this species. Its habit of hunting at modest heights (3–15 metres) and along predictable routes over water makes it more accessible than many bat species for patient photographers. Focus on distinguishing features such as the reddish-brown fur with pale tips and the darker face and ears to confirm identification in photographs.