The greater mouse-eared bat (Myotis myotis) is the largest European Myotis species and easily recognizable as one of the largest bat species occurring in Germany. Although there is a strong risk of confusion with the lesser mouse-eared bat (Myotis blythii), the latter is only found in southern Europe. The greater mouse-eared bat collects larger ground-dwelling insects, especially ground beetles, in flight or even crawling along the ground. In doing so, it often listens for the sounds made by the beetles themselves as they crawl to find them.
Prefers deciduous, rarely mixed and coniferous forests without dense vegetation underground, so that it can hunt close to the ground.
Nursery roost associations mainly in attics, rarely underground, e.g., in basements. Individual males also in tree cavities, bat or bird boxes in forest. Hibernates from October to March/April underground in caves, tunnels, cellars, etc. Migrations to winter roosts up to 300 km.
Mating activity begins as early as August and is usually completed by October. Birth of young from late May to June. First excursions from the quarters from about 5 weeks.
- Head-torso length: 65-82 mm - Forearm length: 55-64 mm - Wing span: 360-420 mm
25–40 g
Upper side medium gray to yellowish. Underside white-gray.
Snout hairy, in older animals hairless, which is short, broad and strong.
- Long and broad - Ear margin 7-8 transverse folds, anterior margin curved backwards. - Tragus lanceolate, reaching almost to middle of ear.
Large and broad.
Overall rather slow, but also faster rudder flight or shaking flight with very fast wing movements. Show skillful turning maneuvers. When taking off, the animals push off from the ground like a jump.
Nearly linear frequency modulation with start frequencies at 50-75 kHz and end frequencies at 21-26 kHz. Main frequency at 30-35 kHz. Dry calls, but more powerful than in other Myotis species.
Severe population declines mainly in the 1970s due to use of pesticides and wood preservatives during renovation of church roof trusses. Population has been recovering since then. Red List of Germany (2020): not endangered. IUCN (2016): Least Concern.