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Bat migration

© Cyril Schönbächler

Bats can cover distances superior to 2,000 km. Several long-distance migrating species are known:
  • Nyctalus noctula
  • Nyctalus leisleri
  • Pipistrellus nathusii
  • Vespertilio murinus
  • Nyctalus lasiopterus (?)

When migrating, bats are particularly present at:

  • Coastlines
  • Large rivers
  • Mountain passes

But bat migration is generally poorly documented (and studies mostly concern P. nathusii and N. noctula)

Wind turbines as a threat

Bats take a high toll at wind turbines because of collisions and barotrauma at blades.
  • For instance, N. noctula has a high susceptibility to wind turbine collisions (flies high and migrates)
  • Lasiurus cinereus could go extinct because of wind turbines. It shares biological traits with N. noctula.
  • A large decline for N. noctula was found in France (2006-2019).
  • It is thus urgent to reduce all impacts, including wind turbines.

© Laurent Arthur

A necessary collaboration


  • As bats know no borders, the policy of a single country is not sufficient to efficiently protect migrating bats, and this is why the UNEP/EUROBATS agreement was written and signed.

  • Many of us collect data on bats all around Europe. This represents a huge database if brought together!

  • This scientific collaboration will also include countries who did not sign EUROBATS.


  • Study spatio-temporal changes in bat activity for three migrating bats.
  • Highlight areas of conservation priority for these migrating bats in Europe.
  • Develop a strategy to take these areas into account during wind energy planning.
  • Make this project a large European collaboration.

Target species

The three most common migrating bats in geographical Europe will be studied:

The noctule bat Nyctalus noctula

© Cyril Schönbächler

The lesser noctule bat Nyctalus leisleri

© Boris Baillat

The Nathusius pipistrelle Pipistrellus nathusii

© Celine Le Barz

Geographic range of Nyctalus noctula (© IUCN)

Geographic range of *Nyctalus leisleri* (© IUCN)

Geographic range of *Pipistrellus nathusii* (© IUCN)

For the moment, in order to focus the work effort, no other species will be studied. However, it could be possible, as a perspective, to extend this project to other species quite easily.


  1. Make a proof of concept at the French national scale
    • Distribution maps of acoustic activity for three migrating bats.
  2. Find partners all around Europe
    • Contribution with data
    • Contribution with feedback on method and results.
  3. Evaluate the potential of the European dataset.
  4. Define a method applicable to the dataset.
  5. Create large-scale maps for Europe where data exists.
  6. Create fine-scale maps locally:
    • On a case-by-case basis according to needs and types of use
    • With the help and decision of a local governance?