This is a long-range migratory species (Hutterer et al. 2005) that typically moves over a NE-SW route, with recent records of seasonal movements of 2,200 km between south Lavia and N Spain (Alcade et al. 2020) and a record movement of at least 2,486 km from Russia to the French Alps (Vasenkov et al. 2022). A transitional area in central and north-western Europe where migrating populations mix with resident populations is strongly suspected based on the available evidence (Russ 2022). The species roosts in a range of tree cavities and spaces in buildings and readily colonises bat boxes. Hibernation takes place in trees, buildings or spaces on cliffs. Pipistrellus nathusii feeds mainly on aquatic Diptera with a high percentage of Chironomidae in their diet, but its prey spectrum differs depending on the available habitat, with migrating bats consuming more insects associated with aquatic habitats and summer colonies consuming prey typically found in forested areas. The species selectively exploits prey with high-fat content to balance its fat reserves during long-distance and foraging flights, which is a beneficial digestive adaptation to flying and migration (reviewed in Russ 2022).

Pipistrellus nathusii is a western Palearctic migratory bat species occurring in western, central, and southern Europe, up to Scotland and Sweden, at latitudes of 63°N, and southwards to Spain, southern Italy, Greece, and the main Mediterranean islands such as Sardinia, and Sicily. Old records (not mapped) from Corsica are not confirmed (S. Aulagnier pers. comm.). Individual bats have often been found on North Sea offshore oil platforms and ships. The breeding range is mainly restricted to northeast and central Europe (but scattered records of nurseries are available for many sites from the UK to Switzerland, France, Italy, and east to Crimea) whereas mating and hibernation sites are found in western and southern Europe (reviewed in Russ 2022). The species is typically associated with lowland areas but has been recorded up to 2,200 m in the Alps (Bogdanowicz 1999).

Responses to climate change have been recorded, and increasing numbers of bats hibernating in north-eastern Europe, where they exploit urban heat islands and consequently reproductive and hibernation areas now overlap in central Europe. The range of altitudes where this species can be found varies between 0 and 2,460 m asl (Groupe Chiroptères Rhône-Alpes 2014). The AOO and EOO have not been estimated, but based on the available locality records, they are expected to greatly exceed the threshold for a threatened category.

The global range extends out of Europe to Asia Minor and Transcaucasia.

Pipistrellus nathusii is protected under national law in most range states. It is also protected under international law through the Bonn Convention (Eurobats) and Bern Convention in parts of its range where these apply to and is included in Annex IV of the EU 92/43 Habitats Directive. The primary threat to the survival of this species is mortality associated with wind turbine development. To mitigate this risk, it is essential to conduct appropriate impact assessments and take necessary measures, such as avoiding the placement of wind turbines in sensitive areas or the application of appropriate mitigation. The periodically updated Eurobats guidelines (https://www.eurobats.org/publications/eurobats_publication_series) provide useful guidance on best practices for wind turbine development. Additionally, protecting overground roosts and avoiding the use of pesticides can further aid in the conservation of the species.