Atlas der Säugetiere Nordrhein-Westfalens

Wimperfledermaus

100 entries

Geoffroy′s bat

Rote Liste NRW: 2 Stark gefährdet

  entry

Myotis emarginatus

As a species of the Genus Myotis, the medium-sized Geoffroy′s Bat has a light-coloured but yellowish belly. The relatively long, slightly woolly dorsal fur is middle-brown and often transitions to reddish-brown; juveniles are darker and grey-brown. The eponymous fringes on the margin of the tail membrane are barely visible. A good characteristic is the distinctive step on the outer margin of the ears as well as numerous small pimples in the ear.
As for its occurrence, Geoffroy ′s Bat is clearly tied to settlements. Its hunting areas are in forests, structurally rich open parkland and orchard areas as well as smaller bodies of water. Along with flying insects, it catches great numbers of spiders and insects, which are gleaned off leaves, branches and tree trunks. However, during poor weather, Geoffroy ′s Bats also glean spiders and flies off walls and ceilings in animal barns. Roost and hunting areas can be over 10 km distant from each other and are often connected by guiding structures like forests, parkways, hedges and ditches. In contrast to Daubenton ′s Bat, Geoffroy ′s Bat can hardly be observed during the hunt because it emerges far after sunset and returns relatively early and prefers to hunt high up in the area of the canopy. The nursery colonies of this thermophilic species in Central Europe are located in buildings and in Southern Europe also in caves. They use spacious attics, which can be quite bright. There they hide in hollow beams and corners of the rafters; during high temperatures, they also hang openly, sometimes in larger clusters of several dozen animals. The males usually sleep singly under eaves or in tree cavities. Geoffroy ′s Bats spend the winter in subterranean roosts, like caves, mines and cellars. The young are born in June, in part not until July. Some of the animals stay in the nursery colonies until at least September.
Geoffroy ′s Bat belongs to the rarest bats in NRW. Two nursery colonies are currently known in Hensberg County in old abandoned farms (as of 2014). They are located right on the border to the Netherlands. There, in Limburg, as well as in Belgium, exist several colonies of the species of which the largest in some years encompassed 800 or more females. Individual males and females were recorded in Heinsberg County more than 10 kilometres from the nursery roost and an animal banded here was retrieved in a clay pit in Valkenburg (Limburg, Netherlands, 33 km SW). A few of the species have been recorded to be widely distributed over NRW — from Moers and Dortmund, from Steinfurt County and the Sauerland and from the Bonn area and the Eifel where, after the year 2000, individual records of hibernating and swarming animals were obtained.
The calls of Geoffroy′s Bat are very characteristic, and good recordings of call series can be suitable as a record of the species in additional areas.

Author

Michael Straube

Citation

Straube M (2024): Wimperfledermaus (Myotis_emarginatus).In: AG Säugetierkunde NRW — Online-Atlas of the mammals of North Rhine-Westphalia. Downloaded from saeugeratlas-nrw.lwl.org on 2024/12/03