Greater mouse-eared bat

Myotis myotis Borkhausen, 1797


Other names
CatalanRatpenat rater gros
SpanishMurciélago ratonero grande
EnglishGreater mouse-eared bat
FrenchGrand murin
BasqueSaguzar arratoi-belarri handi
GalicianMorcego de orellas de rato grande


One of the largest bat species in Europe, with head-body length of 40-60 mm, wingspan ranging between 350 to 450 mm and forearm between 55 to 66.9 mm. They have different colouration in the dorsum varying between reddish and brown, as well as in the ventre; which can be white or pale cream or beige. Juveniles tend to have more greyish colours. Wings are usually dark grey or dark brown. The ears and snout are remarkably large, which makes its identification easier. The ears can measure up to 28 mm. Their weight oscillated between 20 and 27 g.

Il·lustració de Toni Llobet extreta de l'obra Els ratpenats de Catalunya (BRAU Edicions, 2012).


Found from the west of Europe (Portugal) to the East (Turkey). Its distribution range includes the Balearic archipelago and Sicily. In the north, its distribution limits with the Netherlands, north of Germany, south of Denmark, north of Poland and East of Ukraine. It may be extinct in Britain and it is currently not found in the north of Africa, Corsica, Sardinia or Malta. 


As a strict forest-dwelling bat species, it is usually found in caves and underground roosts. It has been reported foraging in several different environments such as forests and open spaces, although mostly in habitats with low vegetation, from the sea level until the 2000 m of altitude.


Mainly arthropods, including Coleoptera, Orthoptera and Aracnida, generally big arthropods that are grazing on the floor. In order to better detect its prey, it tends to fly slow and near the floor. 


Maternity colonies can harbour up to  few thousands of  individuals, commonly in caves or mines, whose location vary regionally. These colonies are composed by females and their pups, as the number of males in these colonies are always really low. Females usually start reproducing after one or two years of life. Females congregate from the end of March to August, and pups are generally born from May to June, and become independent after 6 or 8 weeks.


Similar to all typical Myotis calls. The pulses from this species is very modulated and its frequency range includes frequencies from 170 kHz to 26 kHz and have duration of 6 or 10 ms. 


Generally not considered migratory, although they can fly each night between 5 and 26 km to reach their foraging areas, and about 50 to 100 km between summer and winter roosts.


According to The IUCN Red List, this specie is classified as Least Concern. Protected by national law in many countries and directed by the Eurobats Agreement, Bern Convention and EU Habitats and Species Directive. The population of these bats have been exponentially declining in the last decades but in the actual distribution its occurrence is now common.