Barbastelle Bat

The Barbastelle is a medium-small European bat notable for its distinctive pug-like face and broad, joined ears. It roosts in forests and old buildings across temperate Europe and is considered a flagship species for old-growth woodland conservation. It is remarkable for its unique, quiet echolocation calls that help it evade detection by moth prey with hearing adapted to bat sonar.

Europe, from the UK and Iberia to the Caucasus, including Lithuania where the given coordinates are located

Found throughout most of Europe from the British Isles and Iberian Peninsula in the west to the Caucasus and parts of the Near East in the east, including Lithuania, Poland, France, Germany, and the Mediterranean countries.

Altitude and depth

Typically found from sea level up to about 1,500-2,000 meters in mountainous regions of central and southern Europe.

Seasonal movements

Hibernates in winter (roughly October to March/April) in caves, tunnels, cellars, and tree hollows; migrates locally between summer forest roosts and winter hibernacula, though migrations are generally short-distance.

Primarily associated with mature deciduous and mixed forests with abundant dead wood, but also uses hedgerows, orchards, and riparian woodland; roosts under loose bark, in tree cavities, and occasionally in buildings.

Adaptations to its environment

Possesses low-intensity, narrowband echolocation calls that allow it to approach eared moths undetected, a key adaptation for hunting tympanate prey. Its dense fur and ability to enter torpor help it survive cold periods, and flexible roosting habits allow use of both natural and anthropogenic structures.

Classified as Near Threatened by the IUCN due to ongoing habitat loss and population declines across parts of its range, though it remains locally common in some well-forested regions. It is also listed on Annex II of the EU Habitats Directive, requiring special area protections.

Estimated population

Population size is not precisely known but is considered to be declining in many parts of its range, particularly in intensively managed agricultural and forestry landscapes; some strongholds remain in Eastern Europe.

Loss and fragmentation of mature forest habitat, removal of dead wood and old trees used for roosting, agricultural intensification and pesticide use reducing moth prey, and disturbance of hibernation and roost sites.

Diseases and parasites

Susceptible to ectoparasites such as bat flies and mites, and like many European bats, may carry certain lyssaviruses (rabies-related), though documented cases in this species are rare.

Protected under the EU Habitats Directive (Annex II and IV) and the Eurobats Agreement; conservation actions include designation of Special Areas of Conservation, retention of veteran trees and deadwood in managed forests, and roost/hibernacula protection programs in several countries.

Recommended actions

Prioritize retention and creation of deadwood and veteran trees in managed forests, protect and monitor known hibernacula and maternity roosts, reduce pesticide use to maintain moth prey populations, and expand forest connectivity between roosting and foraging areas.

Distinctive blackish-brown to dark grey fur, a flattened pug-like face, and broad ears that are joined at the base across the forehead, giving it a unique silhouette among European bats. The wings and tail membrane are dark, and the fur often has a slightly frosted appearance due to pale-tipped hairs.

Size

Head-body length approximately 45-58 mm, with a wingspan of about 245-290 mm.

Weight

Typically weighs between 6-13 grams, with slight seasonal variation due to fat reserves before hibernation.

Distinctive features

The combination of a flat, pug-like snout and ears fused at the base distinguishes it clearly from other Vespertilionid bats in Europe, none of which share this exact ear structure.

Differences between males and females

Sexual dimorphism is minimal, with females being slightly larger than males on average, a common pattern among many bat species.

Forms small to moderate maternity colonies of typically 10-100 individuals in summer, often switching between multiple roost trees within a local area; males tend to roost more solitarily or in small groups outside the breeding season.

When it is active

Strictly nocturnal, emerging relatively late after dusk to forage, with activity peaks in the first few hours after sunset and before dawn.

Diet

Insectivorous, with a diet dominated by moths (Lepidoptera), especially small and medium-sized eared moths, supplemented occasionally by other soft-bodied insects.

How it feeds and hunts

Uses quiet, low-amplitude echolocation calls that reduce detection by moths' ultrasonic hearing, allowing stealthy aerial hawking and gleaning of prey from foliage in cluttered forest environments.

Communication

Communicates primarily through echolocation calls for navigation and hunting, along with social calls used for roost-mate recognition and mother-pup contact within colonies.

Interactions with other species

Preyed upon occasionally by owls and other nocturnal predators; competes with other insectivorous bat species for moth prey, though its unique low-intensity calls give it a niche advantage in hunting eared moths.

Role in its ecosystem

Plays an important ecological role as a natural regulator of nocturnal insect populations, particularly moths, contributing to pest control services in forest and agricultural ecosystems.

Mating occurs in autumn with delayed fertilization, and after hibernation females give birth to typically one (occasionally two) pup in June or July following an active gestation period of about 6-8 weeks post-fertilization.

Raising the young

Females raise pups in maternity colonies, nursing them for about 4-6 weeks until they are capable of independent flight and foraging; males do not participate in offspring care.

Maturity and lifespan

Reaches sexual maturity at around 1-2 years of age; lifespan in the wild can reach up to 20-23 years, making it relatively long-lived for its small body size.

Classification

Class Mammalia > Order Chiroptera > Family Vespertilionidae > Genus Barbastella > Species Barbastella barbastellus

Subspecies

Barbastella barbastellus barbastellus (most of Europe) and Barbastella barbastellus guanchae (Canary Islands, sometimes treated as a separate species)

Scientific synonyms

Vespertilio barbastellus (original name given by Schreber in 1774)

Recent studies

Recent research has focused on its unique low-amplitude echolocation as an evolutionary counter-adaptation to moth hearing, as well as landscape genetics studies examining population connectivity across fragmented European forests.

Genome and DNA

The species has a diploid chromosome number of 2n=32, typical for many vespertilionid bats, though detailed genomic studies remain limited.

Compared with similar species

Compared to other Vespertilionid bats like the brown long-eared bat, the Barbastelle has shorter, differently shaped ears joined at the base and a much flatter facial profile, along with quieter echolocation calls suited to stealth hunting.

The Barbastelle's whisper-quiet echolocation calls are so faint that scientists nickname it a 'stealth bat' for its ability to sneak up on moths with sensitive hearing. Its pug-like face and fused ears make it one of the most visually distinctive bats in Europe.

Where and how to see it

Best observed at dusk near mature woodland edges or river corridors in rural Europe during summer months, using bat detectors tuned to its characteristic quiet, low-frequency calls; hibernation sites in caves or tunnels can also be surveyed with appropriate permits in winter.

Risks to humans

No notable risk to humans; like all bats, direct handling should be avoided due to a very small potential risk of rabies-related virus transmission.

Human uses

Not used commercially, but valued for pest control services in agricultural and forest ecosystems, and serves as an indicator species for forest habitat quality in conservation monitoring programs.

Myths and legends

Like many bats, it has historically been associated with folklore surrounding witches and darkness in European rural traditions, though no myths are specific to this species alone.