Adaptive echolocation sounds in the batRhinopoma hardwickei
Rhinopoma hardwickei were studied under natural conditions in the Madurai region of southern India.
Frequency modulated (FM) sounds of 3 ms duration were emitted shortly before landing and during times when 10–70 individuals were flying in clusters as they left their roosts.
Constant frequency (CF) sounds of 48 ms duration were produced in open space by single flying bats and by bats flying in a group. At these times the most intense component was the second harmonic.
When bats flew in a group the frequencies of the CF-sounds emitted by different individuals were in three different bands (30.0, 32.5, and 35.0 kHz) whereas single flying bats used only 32.5 kHz. Evidence is presented that shows thatRhinopoma hardwickei flying in groups regulate the frequency of their individual CF-components and in this way they avoid jamming one another.
After landing a pure tone multi-harmonic sound of long duration (maximally 100ms) is emitted. In this sound the fundamental frequency is dominant. Its significance, either communicative and/or echolocative, is not clear.
The possible role of different types of sounds recorded in different orientation situations is discussed.
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- Beuter K (1980) A new concept of echo evaluation in the auditory system of bats. In: Busnel AG, Fish J (eds) Animal sonar systems. Plenum Press, New York, pp 747–762Google Scholar
- Harnischfeger G (1980) Brainstem units of echolocating bats coding binaural time differences in the microsecond-range. Naturwissenschaften 67:314–315Google Scholar
- Miller LA, Degn HJ (1981) The acoustic behavior of four species of vespertilionid bats studied in the field. J Comp Physiol 142:67–74Google Scholar
- Neuweiler G (1980) Auditory processing of echoes. Part I: Peripheral processing. In: Busnel RG, Fish J (eds) Animal sonar systems. Plenum Press, New York, pp 519–548Google Scholar
- Novick A (1965) Echolocation of flying insects by the batChilonyc-terispsilotis. Biol Bull 128:297–314Google Scholar
- Pye JD (1972) Bimodel distribution of constant frequencies in some hipposiderid bats. J Zool (Lond) 166:323–335Google Scholar
- Pye JD (1978) Some preliminary observations on flexible echolocation systems. Proc Fourth Int Bat Res Conf, Olembo RJ, Castelino JB, Mutere FA (eds). Kenya Lit Bureau, Nairobi, pp 127–136Google Scholar
- Schnitzler H-U (1973) Control of Doppler shift compensation in the greater horseshoe bat,Rhinolophus ferrumequinum. J Comp Physiol 82:79–92Google Scholar
- Schuller G, Beuter K, Schnitzler H-U (1974) Response to frequency shifted artificial echoes in the batRhinolophus ferrumequinum. J Comp Physiol 89:275–286Google Scholar
- Simmons JA, O'Farrell MJ (1977) Echolocation by the long-eared bat,Plecotus phyllotis. J Comp Physiol 122:201–214Google Scholar
- Simmons JA, Stein RA (1980) Acoustic imaging in bats sonar: echolocation signals and evolution of echolocation. J Comp Physiol 135:61–84Google Scholar
- Simmons JA, Lavender WA, Lavender BA et al. (1974) Target structure and echo spectral discrimination by echolocating bats. Science 186:1130–1132Google Scholar
- Simmons JA, Howell DJ, Suga N (1975) Information content of bat sonar echoes. Am Sci 63:204–215Google Scholar
- Simmons JA, Fenton MB, O'Farrell MJ (1979) Echolocation and pursuit of prey by bats. Science 203:16–21Google Scholar