Journal of comparative physiology

, Volume 131, Issue 2, pp 161–167 | Cite as

Echolocation and obstacle avoidance in the hipposiderid batAsellia tridens

  • Y. Gustafson
  • H. -U. Schnitzler


The echolocation sounds of the hipposiderid batAsellia tridens consist of a constant frequency (cf) component followed by a frequency modulated (fm) terminal downward sweep of 19–21 kHz. The cf-part constitutes about 7/10 of the entire signal. In individual roosting animals the frequencies of the cf-part of consecutive sounds (resting frequency) is kept very constant but varies from bat to bat. In 18Asellia tridens resting frequencies between 111–124 kHz have been measured.

The sound duration in roosting and free flying bats is between 7–10 ms. In the approach and terminal phase of bats landing on a perch or flying through obstacles, the sound duration is reduced and the repetition rate increased the nearer the bat approaches the target. At the end of the terminal phase sound durations of a minimum of 3 ms have been measured. Flying bats lower their emission frequency in order to compensate for Doppler shifts caused by the flight movement. The echofrequency is therefore kept constant about 150–200 Hz above the resting frequency.

In flights through obstacles consisting of vertically stretched wires with different diameters, the bats were able to avoid wires down to a diameter of 0.065 mm whereas at 0.05 mm the percentage of flights without collisions is far below the chance level. The results demonstrate that the echolocation behavior of the hipposiderid batAsellia tridens does not differ fundamentally from that of rhinolophid bats. As a result, a new suggestion for categorization of bats producing cf-fm orientation sounds is put forward.


Repetition Rate Doppler Shift Chance Level Obstacle Avoidance Terminal Phase 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



constant frequency component


frequency modulated component


probability of collision-free flights through an obstacle of ertically tretched wires


interval between wires


minimal diameter of a bat with folded wings; Θ, angle at which a bat approaches an obstacle


frequency of the cf-component of the emitted sound


frequency of the cf-component of the echo


frequency of the cf-component of the sounds recorded with the microphone


speed of sound


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  1. Bateman, G.C., Vaughan, T.A.: Nightly activities of mormoopid bats. J. Mammal.55, 45–65 (1974)Google Scholar
  2. Brosset, A.: La biologie des chiroptères. Paris: Masson et Cie. 1966Google Scholar
  3. Flieger, E., Schnitzler, H.-U.: Ortungsleistungen der FledermausRhinolophus ferrumequinum bei ein- und beidseitiger Ohrverstopfung. J. Comp. Physiol.82, 93–102 (1973)Google Scholar
  4. Goldman, L.J., Henson, O.W. Jr.: Prey recognition and selection by the constant frequency bat,Pteronotus p. parnellii. Behav. Ecol. Sociobiol.2, 411–419 (1977)Google Scholar
  5. Griffin, D.R., Webster, F.A., Michael, C.R.: The echolocation of flying insects by bats. Anim. Behav.8, 141–154 (1960)Google Scholar
  6. Grinnell, A.D., Hagiwara, S.: Adaption of the auditory nervous system for echolocation. Z. vergl. Physiol.76, 41–81 (1972)Google Scholar
  7. Konstantinov, A.I., Sokolov, B.V.: Characteristics of ultrasonic orientation signals of horseshoe bat (Rhinolophidae). J. Evol. Biochem. Physiol.5, 90–97 (1969)Google Scholar
  8. Möhres, F.P., Kulzer, E.: Ein neuer, kombinierter Typ der Ultraschallorientierung bei Fledermäusen. Naturwissenschaften42, 131–132 (1955)Google Scholar
  9. Novick, A.: Orientation in paleotropical bats. I. Microchiroptera. J. Exp. Zool.138, 81–154 (1958)Google Scholar
  10. Pye, J.D.: Bimodal distribution of constant frequencies in some hipposiderid bats (Mammalia: Hipposideridae). J. Zool. (Lond.)166, 323–335 (1972)Google Scholar
  11. Pye, J.D.: Some preliminary observations on flexible echolocation systems. Proceedings of the fourth international bat research conference. Olembo, R.J. et al. (eds.), pp. 127–136. Kenya: Kenya Literature Bureau 1978Google Scholar
  12. Pye, J.D., Roberts, L.H.: Ear movements in a hipposiderid bat. Nature225, 285–286 (1970)Google Scholar
  13. Sales, G., Pye, J.D.: Ultrasonic communication by animals. London: Chapman and Hall 1974Google Scholar
  14. Schnitzler, H.-U.: Discrimination of thin wires by flying Horsehoe bats (Rhinolophidae). In: Animal sonar system, Vol I. Busnel, R.G. (ed.), p. 68–87. Jouy-en-Josas: Laboratoire de Physiologie Acoustique 1967Google Scholar
  15. Schnitzler, H.-U.: Die Ultraschall-Ortungslaute der Hufeisenfledermäuse (Chiroptera-Rhinolophidae) in verschiedenen Orientierungssituationen. Z. vergl. Physiol.57, 376–408 (1968)Google Scholar
  16. Schnitzler, H.-U.: Echoortung bei der FledermausChilonycteris rubiginosa. Z. vergl. Physiol.68, 25–39 (1970a)Google Scholar
  17. Schnitzler, H.-U.: Comparison of the echolocation behavior inRhinolophus ferrumequinum andChilonycteris rubiginosa. Bijdr. Dierk.40, 77–80 (1970 b)Google Scholar
  18. Schnitzler, H.-U.: Control of Doppier shift compensation in the Greater Horseshoe Bat,Rhinolophus ferrumequinum. J. Comp. Physiol.82, 79–92 (1973 a)Google Scholar
  19. Schnitzler, H.-U.: Die Echoortung der Fledermäuse und ihre hörphysiologischen Grundlagen. Fortschr. Zool.21, 136–189 (1973 b)Google Scholar
  20. Schnitzler, H.-U.: Die Detektion von Bewegungen durch Echoortung bei Fledermäusen. Verh. Dtsch. Zool. Ges.1978, 16–33 (1978)Google Scholar
  21. Schnitzler, H.-U., Flieger, E.: Detection of fluttering target movements by the echolocating cf-fm bat,Rhinolophus ferrumequimum. (In preparation)Google Scholar
  22. Simmons, J.A., Howell, D.J., Suga, N.: Information content of bat sonar echos. Am. Sci.63, 204–215 (1975)Google Scholar

Copyright information

© Springer-Verlag 1979

Authors and Affiliations

  • Y. Gustafson
    • 1
  • H. -U. Schnitzler
    • 1
  1. 1.Arbeitsgruppe Neurobiologie, Fachbereich BiologiePhilipps-UniversitätMarburg/LahnGermany

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