Behavioral Ecology and Sociobiology

, Volume 59, Issue 3, pp 443–454 | Cite as

Do echolocation calls of wild colony-living Bechstein's bats (Myotis bechsteinii) provide individual-specific signatures?

Original Article


Social animals often use vocal communication signals that contain individual signatures. As bats emit echolocation calls several times per second to orient in space, these might seem ideal candidates for conveying the caller's individual identity as a free by-product. From a proximate perspective, however, coding of caller identity is hampered by the simple acoustic structure of echolocation signals, by their task-specific design and by propagation loss. We investigated the occurrence of individual signatures in echolocation calls in individually marked, free-living Bechstein's bats (Myotis bechsteinii) in a situation with defined social context in the field. The bats belonged to two different colonies, for both of which genetic data on relatedness structure was available. While our data clearly demonstrate situation specificity of call structure, the evidence for individual-specific signatures was relatively weak. We could not identify a robust and simple parameter that would convey the caller's identity despite the situation-specific call variability. Discriminant function analysis assigned calls to call sequences with good performance, but worsened drastically when tested with other sequences from the same bats. Therefore, we caution against concluding from a satisfactory discrimination performance with identical training and test sequences that individual bats can reliably be told apart by echolocation calls. At least the information contained in a single call sequence seems not to be sufficient for that purpose. Starting frequencies did give the best discrimination between individuals, and it was also this parameter that was correlated with genetic relatedness in one of our two study colonies. Echolocation calls could serve as an additional source of information for individual recognition in Bechstein's bats societies, while it is unlikely that a large number of individuals could be reliably identified in different situations based on echolocation alone.


Vocal signature Individual recognition Echolocation Vespertilionidae Relatedness 



We received financial support from Swiss National Science Foundation (SNF, 31-59556.99, to GK) and the German Research Foundation (DFG Si 816/2-1, to BMS). We thank Karsten Reckardt and Nicolas Bansac for helping with the fieldwork, Claudia Böing for excellent technical assistance in call analysis and Ingrid Kaipf for preparing Fig. 3. Wolf Blanckenhorn, Peter Pilz and Kamran Safi are acknowledged for statistical advice. The latter and Brock Fenton, Martin Obrist and Marta Manser provided helpful comments on earlier versions of this manuscript. Comments by two anonymous reviewers and Gerald Wilkinson greatly helped to improve the manuscript. The study was conducted under licence from the nature conservancy department of the government of Lower Frankonia and complied with German laws.


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Copyright information

© Springer-Verlag 2005

Authors and Affiliations

  1. 1.Tierphysiologie, Zoologisches InstitutUniversität TübingenTübingenGermany
  2. 2.Zoologisches InstitutUniversität ZürichZürichSwitzerland

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