Plecotus auritus (Linnaeus, 1758)

Nomenclature and Classification

The brown long-eared bat, also called the common long-eared bat, with the scientific name Plecotus auritus, is a small insectivorous bat native to Eurasia.

Distinctive Ear Features

It is marked by distinctive long ears that feature a unique fold.

Visual Similarity to Related Species

This species is extremely similar in appearance to the much rarer grey long-eared bat, which was not confirmed as a separate distinct species until the 1960s.

Adult Body Measurements

Full grown adult brown long-eared bats have a body length ranging from 4.5 to 4.8 cm, a tail length of 4.1 to 4.6 cm, a forearm length of 4 to 4.2 cm, and ears that measure 3.3 to 3.9 cm long.

Ear Size as Identification Marker

This ear size easily distinguishes long-eared bats from most other bat species.

Flight Characteristics

Compared to other bat species, brown long-eared bats are relatively slow fliers.

European Distribution

The brown long-eared bat is found across nearly all of Europe, excluding Greece, southern Italy, and southern Spain.

Eastern Range Limit

Its range extends east as far as the Urals and Caucasus.

UK Distribution Records

Distribution records for the United Kingdom are available on the National Biodiversity Network website.

Building Roost Habits

Brown long-eared bats regularly use buildings as roosts, staying in undisturbed roof spaces either alone in crevices and timber, or in small clusters around chimneys and ridge ends.

Alternative Roost Sites

This species also roosts in tree hollows, bat boxes, and caves; caves are particularly important as winter hibernation sites.

Tree Roost Placement

Tree roosts may be located very close to the ground.

Roost Emergence Timing

Bats usually emerge from their roost sites only after full darkness, around one hour after sunset.

Hunting Locations and Timing

This species hunts above woodland, and will often hunt during the day.

Diet Composition

Its diet consists mostly of moths, but also includes earwigs, flies, and beetles.

Prey Capture Method

It gleans these insects directly from leaves and bark.

Prey Detection Senses

Instead of relying on echolocation, this bat likely detects prey using both sight and sound, aided by its large eyes and ears.

Visual Prey Detection Study

A 2003 study conducted by Eklöf and Jones confirmed that brown long-eared bats are capable of detecting prey visually.

Experimental Cue Preference

Under controlled experimental conditions, the bats showed a preference for scenarios where both sonar and visual cues were available.

Experimental Cue Importance Findings

Even so, visual cues were more important than sonar cues, and the bats could not detect prey using only sonar cues.

Cluttered Environment Prey Location

Because brown long-eared bats have relatively large eyes and ears, it is thought that a combination of visual input and passive listening allows this species to locate prey effectively in cluttered environments.