Brown Long-eared Bat

Identification

The brown long-eared bat is one of Europe's most distinctive bat species, instantly recognizable by its remarkably long ears measuring 3.3–3.9 cm in length. These ears bear a characteristic fold that sets them apart from nearly all other bat species in their range. It is extremely similar in appearance to the much rarer grey long-eared bat, which was only validated as a distinct species in the 1960s, so careful observation may be needed to distinguish between the two. An adult brown long-eared bat is quite small, with a body length of 4.5–4.8 cm, a tail of 4.1–4.6 cm, and a forearm length of 4–4.2 cm, making it a truly diminutive creature.

Compared to other bat species, brown long-eared bats are relatively slow flyers. They possess relatively large eyes as well as their prominent ears, reflecting their unusual hunting strategy that relies heavily on vision and hearing rather than echolocation alone.

Range & Habitat

The brown long-eared bat is found throughout Europe, with the notable exception of Greece, southern Italy, and southern Spain. Its range extends eastward to the Urals and Caucasus mountains. This widespread Eurasian species occupies diverse roosting habitats, regularly utilizing undisturbed roof spaces in buildings, where they may roost singly in crevices and timber or cluster around chimneys and ridge ends. They also make use of treeholes, bat boxes, and caves, with cave roosts being particularly important as winter hibernation sites.

These bats hunt above woodland, often during daylight hours, taking advantage of their visual hunting abilities. They typically emerge from their roost sites only after dark, generally around an hour after sunset.

Behaviour & Diet

The brown long-eared bat employs a highly unusual hunting strategy for a bat species. Rather than relying primarily on echolocation to locate prey, this species hunts by sight and sound, using its large eyes and ears to detect insects. A 2003 study by Eklöf and Jones demonstrated that brown long-eared bats can visually detect prey and actually showed a preference for hunting situations where both sonar and visual cues were available. Remarkably, visual cues proved more important than sonar cues, and the bats were unable to detect prey using only echolocation.

The diet consists primarily of moths, though earwigs, flies, and beetles are also taken, typically gleaned directly from leaves and bark. Their hearing is exceptionally sensitive—acute enough to hear a moth in flight—allowing them to hunt effectively by passive listening alone. This specialized hunting strategy likely evolved because their moth prey evolved the ability to hear echolocation calls and take evasive action.

Best Time & Places to See It

Brown long-eared bats are most active during the hours just after sunset, when they emerge from their roosts to hunt. Observers should look for them above woodland habitats, where they hunt both day and night. Buildings with undisturbed roof spaces, particularly older structures, may harbor roosting individuals. In winter, cave systems become important sites where these bats hibernate.

Photography Tips

Photographing brown long-eared bats in flight presents significant challenges due to their emergence in darkness and their relatively slow, maneuverable flight. Patient observers stationed near known roost sites during the twilight emergence period may have the best opportunities. The distinctive ears make positive identification straightforward in photographs, though distinguishing them from the rare grey long-eared bat requires careful attention to detail. Their hunting behavior close to vegetation in woodland settings offers potential opportunities for capturing them in their natural foraging habitat.