Daubenton's bat (Myotis daubentonii) — Vorstman's guide to the mammals of Europe

Tracks

Maternity colonies are in tree holes, rotten branches and abandoned woodpecker holes, and also in bat boxes, under and in bridges and in buildings. Small colonies change roost every three to five days, so that one colony may use up to 40 tree holes in a year; as a result there are usually few droppings below a roost. In winter the bats hang in caves, mines, bunkers and other underground spaces at 3 to 8 °C, and also in tree holes; in the north-east of the range they gather in large numbers, such as 20,000 in Nietoperek in Poland and up to 5000 in Berlin. From September to November they gather in large numbers at swarming sites in caves, mines and buildings.

Identification

A small to medium-sized bat: forearm 33 to 42 mm, weight 6 to 10 g. The fur of back and underside is grey or brownish, with dark hair bases and paler, sometimes reddish tips; the underside is slightly paler than the back. The wings are dark brown or grey; juveniles are darker than adults. The ears are fairly small and triangular, with four to five folds; the tragus is straight, short and pointed, reaching about half the ear. The feet are large and covered with long hairs or bristles. The wing starts at the base of the toes; the tail membrane is naked. Echolocation consists of short, strongly modulated calls starting above 60 kHz and ending below 30 kHz, with maximum energy around 40 kHz.

Similar species

The pond bat (M. dasycneme) hunts in the same way but is clearly larger (forearm 43 to 49 mm), has the wing attached at the heel and a broad, short tragus, and flies higher and faster over the water. The long-fingered bat (M. capaccinii) of the Mediterranean region has larger feet, a densely haired tibia and a wing attached at the end of the tibia. The whiskered and Brandt's bats (M. mystacinus, M. brandtii) have a darker face and dark ears and clearly smaller feet, and hunt less exclusively over water. On a bat detector the calls overlap with those of other Myotis species; hunting behaviour just above water together with the sound often gives an indication, but not a conclusive identification.

Habitat

Mainly waterside habitats and water, natural and artificial: rivers, streams, ponds, lakes and canals, as well as woodland, parks and traditional orchards, from sea level to about 1400 m. The bats roost in woodland and commute from there to the water; they forage preferably over calm water with open banks, but also over grassland, clearings and along woodland edges. In the Mediterranean region the distribution is patchy.

Where the animal is most at home, classified with EUNIS — the European standard for habitats.

Distribution

Most of Europe and western Asia, from southern Fennoscandia, the British Isles and the Iberian Peninsula east to western Russia (to the Omsk region), the Caucasus and northern Turkey. In the Mediterranean region the range is patchy.

Native
dark = core range, pale = thinly spread

Recording density, not a range: the map shows where the species is reported and draws no boundary around its range. The records of GBIF (2006-01-01 – 2026-12-31) are counted per 0.7° grid cell and divided by everything reported as a mammal in that same cell, so the number of observers does not shape the picture. Colour depth follows that share and fades out gradually, so the map does not follow national borders. Which of the four colours a cell takes is decided country by country from the literature, not from the records. Country outlines: Natural Earth (public domain).

Way of life

Daubenton's bat hunts 5 to 40 cm above a calm water surface and takes insects from the water with its feet or tail membrane, or in flight. In many areas the diet consists mainly of flies, such as non-biting midges, as well as hymenopterans, bugs and moths; in experiments the species also caught fish. The bats emerge after sunset and follow linear landscape features such as woodland edges, ditches and tracks to the water, often in groups of two to six; outside the breeding season up to 10 km in a straight line. Maternity colonies form in May or early June and number from a few tens to a few hundred females, at some sites up to 600. Females are sexually mature after their first year. The young, usually one, are born between mid-June and July and fly after three to four weeks. During the maternity period males roost in the colony or elsewhere, in cellars, mines or tunnels. Mating takes place from September to November, especially in October and November, at swarming sites to which bats travel up to 30 km. The species is considered non-migratory, but may move 150 to 304 km between maternity and hibernation roosts.

Where and when to look

On a summer evening over a pond, canal or calm river Daubenton's bat can be seen in the beam of a torch shone at a low angle across the water, as a bat flying back and forth in low, fast runs just above the surface. With a bat detector set to about 40 kHz the hunting can be followed as a regular series of ticks. Hibernation and swarming sites are not disturbed.

Conservation status

Least Concern (LC, 2020). The species is abundant in many parts of its range, especially in central and eastern Europe. Some monitoring programmes indicate increases in distribution and numbers, but numbers fluctuate strongly between areas. It is listed in Annex IV of the Habitats Directive and is covered by the Bern Convention and the EUROBATS Agreement.

Scientific name

Myotis daubentonii | (Kuhl, 1817)

Kuhl described the species in 1817 as Vespertilio daubentonii; because it was later moved to another genus, the author and year stand in brackets. Myotis is Greek, from mys, genitive myos, 'mouse', and ous, genitive ōtos, 'ear': 'mouse-ear'. daubentonii honours the French naturalist Louis Jean-Marie Daubenton (1716–1800), who supplied the anatomy for Buffon's Histoire naturelle. The specimen the first description was based on came from Germany, Hesse.