Journal of Comparative Physiology A

, Volume 198, Issue 9, pp 683–693

Convergence of reference frequencies by multiple CF–FM bats (Rhinolophus ferrumequinum nippon) during paired flights evaluated with onboard microphones

  • Yuto Furusawa
  • Shizuko Hiryu
  • Kohta I. Kobayasi
  • Hiroshi Riquimaroux
Original Paper

DOI: 10.1007/s00359-012-0739-9

Cite this article as:
Furusawa, Y., Hiryu, S., Kobayasi, K.I. et al. J Comp Physiol A (2012) 198: 683. doi:10.1007/s00359-012-0739-9

Abstract

The constant frequency component of the second harmonic (CF2) of echolocation sounds in Rhinolophus ferrumequinum nippon were measured using onboard telemetry microphones while the bats exhibited Doppler-shift compensation during flights with conspecifics. (1) The CF2 frequency of pulses emitted by individual bats at rest (Frest) showed a long-term gradual decline by 0.22 kHz on average over a period of 3 months. The mean neighboring Frest (interindividual differences in Frest between neighboring bats when the bats were arranged in ascending order according to Frest) ranged from 0.08 to 0.11 kHz among 18 bats in a laboratory colony. (2) The standard deviation of observed echo CF2 (reference frequency) for bats during paired flights ranged from 50 to 90 Hz, which was not significantly different from that during single flights. This finding suggests that during paired flights, bats exhibit Doppler-shift compensation with the same accuracy as when they fly alone. (3) In 60 % (n = 29) of the cases, the difference in the reference frequency between two bats during paired flights significantly decreased compared to when the bats flew alone. However, only 15 % of the cases (n = 7) showed a significant increase during paired flights. The difference in frequency between two bats did not increase even when the reference frequencies of the individuals were not statistically different during single flights.

Keywords

Jamming avoidanceReference frequencyResting frequencyDoppler-shift compensation

Abbreviations

BF

Best frequency

CF

Constant frequency

CF2

Constant frequency of the second harmonic component

DSC

Doppler-shift compensation

DSCF

Doppler-shifted constant frequency

FM

Frequency modulated

Frest

Resting frequency

IC

Inferior colliculus

IPI

Interpulse interval

JAR

Jamming avoidance response

TF

Terminal frequency

Copyright information

© Springer-Verlag 2012

Authors and Affiliations

  • Yuto Furusawa
    • 1
  • Shizuko Hiryu
    • 1
  • Kohta I. Kobayasi
    • 1
  • Hiroshi Riquimaroux
    • 1
  1. 1.Faculty of Life and Medical Sciences, Neurosensing Bionavigation Research CenterDoshisha UniversityKyotanabeJapan