Brandt's bat

Myotis brandtii (Eversmann, 1845)
Vespertilionidae

Least Concern

Other names
CatalanRatpenat de bigotis de Brandt
SpanishMurciélago ratonero de Brandt
EnglishBrandt's bat
FrenchMurin de Brandt
BasqueBrandt saguzar
GalicianMorcego bigotudo de Brandt

Description

Slightly larger than the similar whiskered (Myotis mystacinus) and Alcathoe bat (Myotis alcathoe) but slightly smaller than David's mouse-eared bat (Myotis davidii), this species presents a forearm length between 33 and 38 mm, a wingspan of 190 to 240 mm and weights between 5 and 7 gr. The fur is light-brown with golden tips and the ventral side is not clearly demarcated, being grey coloured.  Younger individuals are almost black and become lighter as they age. The skin areas are brownish, while the lower part of the tragus and the inside of the ear are paler. This species has characteristically long ears, and can be distinguished by other similar "whiskered bats" by its uniformally shaped penis and some dental characters.

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

Distribution

This species is dirtributed mainly in central and northern Europe, including the southern half of Scandinavia. Its distribution reaches Russia up to the Urals and further eastwards, thouh its eastern range limit is unclear because of its confusion with similar species. It is also found in Great Britain and ocasionally in the Caucasus.


Roosts and phenology

Meternity roosts are usually in tree holes, cracks in trunks and behind peeling bark. Also in crevices of wooden cladding of buildings and crevices in roost spaces. Maternity colonies usually comprise 20 to 60 females, but there are some known roosts with more than 200 individuals. In bat boxes around 20 females can be found in mixed colonies with Nathusius's (Pipistrellus nathusii) and soprano pipistrelles (Pipistrellus pygmaeus). A single young is born during June in central Europe and nursery colonies disperse by the end of July. Females become sexually mature only in the second year.

Mostly a sedentary species, with the seasonal migration distance being usually less than 40 km. Five records of movements of more than 100 km are known, with the longest distance being 308 km. Males gather at swarming sites from the beginning of August. Mating takes place at swarming sites and probably in winter roosts, which usually are in caves and mines. Hibernation colonies in buildings have been found, but almos always very close to forest edges or within direct reach of linear woodland elements.


Habitat and diet

This species is much linked to forest habitats and water, mainly occurring in riparian zones, swamps forests, moorlands and other wet areas. It can also be found in mountain forests in altitudes up to 1,500 meters above sea level, especially in southeastern Europe. In northern Europe it has a broader habitat range, including both broadleaf and coniferous forests. In open spaces it uses linear structures like windbreaks and stream courses for commuting.

The diet consists of moths, spiders, dipterans (crane-flies, chironomids and other flies), with an average prey size of 7.3 mm. Depending on the location and season, non-flying prey like spiders, harvestmen and earwigs, can become the main part of the diet. Very agile in flight in riparian, beech and oak forests, over water or along associated vegetation. While mostly hunts close to ground vegetation it can also fly up to the crowns of trees. Hunting grounds are within 10 km from the roost. It can also hunt above water like Daubenton's bat (Myotis daubentonii), but usually higher above the water surface.


Echolocation

The echolocation is characteristic of the Myotis genus with highly modulated FM pulses, usually 4 to 7 ms long. These pulses drop from 100 kHz to 26 kHz. This species is included in the Myotis 50 phonic group.


Status

According to the IUCN Red List and the European Red List 2007 it is considered as Least Concern, with a stable population trend. These bats are protected by national laws and directed by the Eurobats Agreement, the Bern Convention and the EU Habitat and Species Directive. This species is abundant, and the data doesn’t show huge declines in the population. Habitat destruction of riparian and mountain forests has a negative impact. Direct threats include the destruction of roosts through forestry works and isolation of foraging grounds.