Mammals · Chiroptera · Vespertilionidae

Natterer's Bat

Myotis nattereri

Least Concern

The species is abundant and widely distributed; it faces no significant short-term risk. See full glossary

A small to medium-sized myotis bat, with long, silky greyish-brown fur and a whitish belly, the two strongly contrasting. Long ears that extend beyond the muzzle when stretched out, and a pointed tragus. The edge of the uropatagium carries a dense fringe of short, stiff hairs.

Weight

5 g – 12 g

Size

3.7 cm – 5.2 cm

Lifespan

17 years

Diet

Insectivore

Feeds mainly on insects and other invertebrates.

Activity

Nocturnal

Active mainly at night.

Social structure

Colony

Lives in large concentrations, often for breeding reasons.

Sighting difficulty

Easy

Insectivore Nocturnal Colonial Mammal

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Fun facts

It hunts motionless prey: it picks resting daytime insects off foliage and off the ground, flying very close to the vegetation, instead of catching them in the air.
Breeding groups change roost as often as twice a week.
It is hard to count because it hides in very deep crevices: in one roost where no more than three individuals had ever been seen, a gas leak in 1989 killed 306.

Life cycle & biology

Skeleton type: Vertebrate - internal bony skeleton (mammal)
Habitat & environment: Humid deciduous and coniferous woodland, and urban settings, up to about 2,000 m. In summer it roosts in tree holes, buildings and bat boxes; in winter it hibernates in caves, tunnels, mines and cellars, almost always tucked into crevices
Litter / clutch size: A single young a year. The females form breeding colonies of 20 to 80 individuals from April or May on

Sources consulted: IUCN Red List; SECEM - Atlas de los mamíferos terrestres de España; Juste et al. 2018, Acta Chiropterologica 20(2); Dietz y Kiefer 2016, Bats of Britain and Europe; Enciclopedia Virtual de los Vertebrados Españoles (MNCN-CSIC)