The largest European Myotis and one of the most impressive bats in the hand owing to its wingspan, which can exceed 40 cm. This size often surprises those familiar only with small garden bats. It hunts mainly large beetles, locating them on the ground by the sound of their footsteps — a strategy of passive listening almost as important as active echolocation, and one shared almost identically with its sibling species, from which it is virtually impossible to distinguish in both appearance and sound. It forms some of the largest breeding colonies in Europe, with caves hosting several thousand females nursery-roosting together each summer.
A large bat, among the biggest in Europe, with greyish-brown fur, large ears and a robust muzzle. It is virtually indistinguishable in the hand from its sibling species, the Lesser Mouse-eared Bat, differing only in very subtle skull details, muzzle colouration and forearm length; reliable identification between the two almost always requires capture and careful measurement.
tracks and signs: Peak frequency between 28 and 32 kHz. FM pulse with an almost constant component at the end when hunting in open space, appearing on the bat detector as an initially sloped trace that flattens slightly. Long duration, from 8 to 15 milliseconds. It cannot be reliably separated from its sibling species by sonogram: both produce an almost identical acoustic pattern, making this one of the European species pairs where relying solely on sound for identification is strongly discouraged. Beneath large cave colonies, extensive piles of dark, compact guano accumulate, often with clearly visible large beetle elytra among the droppings. It emerges relatively late after sunset.
Open pastureland, open woodland and agricultural areas for hunting, roosting in large warm caves, from lowlands up to mid-mountain zones. Distributed across much of central and southern Europe, and North Africa.
An insectivore specialising in large beetles caught directly on the ground, located largely by the sound of their footsteps rather than active echolocation.
Forms very large breeding colonies in big warm caves, showing strong fidelity to the same roost year after year. Highly sensitive to human disturbance during breeding and hibernation, when it forms dense clusters of thousands of individuals.
Populations have recovered significantly in several areas of Europe thanks to legal protection of major breeding caves, having suffered a marked historical decline through much of the 20th century due to disturbance and destruction of those roosts.
Disturbance and alteration of major breeding and hibernation caves, loss of open pastureland where it hunts due to agricultural intensification, and pesticide use reducing large beetle availability.
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