Atlas der Säugetiere Nordrhein-Westfalens

Große Bartfledermaus

249 entries

Brandt′s Bat

Rote Liste NRW: 2 Stark gefährdet

  entry

Myotis brandtii

Brandt′s Bat has a forearm length of 33-38 mm and a weight of 5-7 g. Subsequently, this bat belongs to the smallest bat species in NRW. Characteristic is its long fur that gets progressively lighter with age where the light hair tips on the upper side cause a noticeable sheen. The still dark juveniles largely resemble the similarly coloured young Whiskered Bats. An unambiguous species identification is possible by means of tooth characteristics and, in the case of the males, by the club-shaped penis. Brandt′s Bat prefers structurally rich landscapes with (riparian and humid) forests, standing water bodies and linear woodlands. It is more strongly tied to forest than the Whiskered Bat. They hunt in closed forests with a sparse shrub layer, over forest trails and along linear vegetation structures in the open and occasionally also in livestock barns. Similar to Daubenton′s Bat, Brandt′s Bats occasionally hunt over water surfaces. The distances covered between roost and hunting ground can encompass 10 km. The search for prey is conducted in fast and manoeuvrable curves at rather low heights. With regard to food, Brandt′s Bat is considered flexible and feeds mainly on butterflies and dipterans like crane flies, flies, midges and spiders.
Nursery roost aggregations of 10 to over 250 females can be found in attics or behind wall sidings, in buildings — preferably located near forest — and more seldom, in tree cavities and bat boxes.
The majority of the confirmed records of Brandt′s Bat in the area of interest, often just single individuals, are from the eastern half of North Rhine-Westphalia. From the Westphalian Bay, nursery colonies of 70 to 100 females are known, but there are also some nurseries in the Sauerland and Siegerland. Brandt′s Bats can cover distances of up to 250 km between their summer and winter roosts. In mine shafts, not just in the hill country, in rock wells and natural caves hibernating Brandt′s Bats were recorded — partly in remarkable numbers. Brandt′s Bats, like other bat species, display a late summer swarming behaviour at their winter roosts. Important swarming and winter roosts are located in Siegen-Wittgenstein County, as well as in the Egge Mountains, in Sauerland and in the central Münsterland. Knowledge gaps regarding the distribution of the species are in Rhineland north of the Eifel and in the western Münsterland.

Author

Frauke Meier und Christina Backhaus

Citation

Meier F, Backhaus C (2025): Große_Bartfledermaus (Myotis_brandtii).In: AG Säugetierkunde NRW — Online-Atlas of the mammals of North Rhine-Westphalia. Downloaded from saeugeratlas-nrw.lwl.org on 2025/04/01