Atlas der Säugetiere Nordrhein-Westfalens

Fransenfledermaus

1633 entries

Natterer′s bat

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Myotis nattereri

With a body size of about 42 — 50 mm, Natterer′s Bat belongs to the intermediate-sized species. The animals reach 5 — 12 g in weight, and the forearm measures 36 — 45 mm. The shape of the ear is characteristic. These are bent slightly upwards and relatively long; bent forward they extent slightly beyond the tip of the snout. The tragus is pointed and reaches half the length of the ear. The S-shaped bend spur reaches to about half the rear edge of the tail membrane.
Natterer′s bats move their nursery colonies in tree cavities and bat boxes. In the Münsterland, there are also nurseries inside or on buildings, for example livestock barns. Recently, Natterer′s Bat roosts were even found in the expansion gaps of bridges. The colonies are small and rarely include more than 30 females.
Natterer′s Bat is a species that preferentially lives in deciduous forests but can also be found in other forest types. Furthermore, they occur in richly structured agricultural landscapes. Natterer′s Bats like to search for their prey near vegetation; they especially like to glean spiders and Diptera off the substrate.
Winter roosts of Natterer′s Bat are in caves, mine shafts, ice cellars, well shafts and other subterranean spaces, like bunkers and creek culverts. Here the animals predominantly hang hidden in cracks and crevices. They typically like to lie on their backs. Body contact with other bats, no matter what species, is commonly observed. In NRW, there are some roosts with several hundred hibernating Natterer′s Bats, as in the Münsterland and in the Eifel and in eastern Westphalia. The largest known hibernaculum is the Meyer well in the Baumberge with about 4000 individuals hibernating annually. Very pronounced is the swarming of bats in front of such roosts in autumn. Natterer′s Bats migrate comparatively late, often not until November or December, into their hibernacula in order to leave them already by mid February. In the winter of 2010/11, there were considerable losses among Natterer′s Bats in NRW, probably because they were surprised by an unusual period of frost in November 2010, which might have prevented them from building up the necessary fat reserves. Meanwhile, the population of Natterer′s Bats is recovering from these population losses and the species can continue to be considered as the most common forest bat in NRW.

Author

Carsten Trappmann

Citation

Trappmann C (2024): Fransenfledermaus (Myotis_nattereri).In: AG Säugetierkunde NRW — Online-Atlas of the mammals of North Rhine-Westphalia. Downloaded from saeugeratlas-nrw.lwl.org on 2024/11/21