E. Schneider & R. M. Hennig (2012): Temporal resolution for calling song
signals by female crickets, Gryllus bimaculatus. J. Comp. Physiol. A 198
(3), 181-191.
Abstract: A behavioural gap detection paradigm was used to determine the
temporal resolution for song patterns by female crickets, Gryllus
bimaculatus. For stimuli with a modulation depth of 100% the critical gap
duration was 6?8 ms. A reduction of the modulation depth of gaps to 50% led
either to an increase or a decrease of the critical gap duration. In the
latter case, the critical gap duration dropped to 3?4 ms indicating a higher
sensitivity of auditory processing. The response curve for variation of
pulse period was not limited by temporal resolution. However, the reduced
response to stimuli with a high duty cycle, and thus short pause durations,
was in accordance with the limits of temporal resolution. The critical
duration of masking pulses inserted into pauses was 4?6 ms. An analysis of
the songs of males revealed that gaps (5.8 ms) and masking pulses (6.9 ms)
were at detectable time scales for the auditory pathway of female crickets.
However, most of the observed temporal variation of song patterns was
tolerated by females. Critical cues such as pulse period and pulse duty
cycle provided little basis for inter-individual selection by females.
URL: http://www.springerlink.com/content/j421v6h1t84771j2/
For reprints please contact R. M. Hennig (email:
M. Hartbauer, A. Stabentheiner & H. Römer (2012): Signalling plasticity and
energy saving in a tropical bushcricket. J. Comp. Physiol. A 198 (3),
203-217.
Abstract: Males of the tropical bushcricket Mecopoda elongata synchronize
their acoustic advertisement signals (chirps) in interactions with other
males. However, synchrony is not perfect and distinct leader and follower
roles are often maintained. In entrainment experiments in which conspecific
signals were presented at various rates, chirps displayed as follower showed
notable signal plasticity. Follower chirps were shortened by reducing the
number and duration of syllables, especially those of low and medium
amplitude. The degree of shortening depended on the time delay between
leader and follower signals and the sound level of the entraining stimulus.
The same signal plasticity was evident in male duets, with the effect that
the last syllables of highest amplitude overlapped more strongly.
Respiratory measurements showed that solo singing males producing higher
chirp rates suffered from higher metabolic costs compared to males singing
at lower rates. In contrast, respiratory rate was rather constant during a
synchronous entrainment to a conspecific signal repeated at various rates.
This allowed males to maintain a steady duty cycle, associated with a
constant metabolic rate. Results are discussed with respect to the
preference for leader signals in females and the possible benefits males may
gain by overlapping their follower signals in a chorus.
URL: http://www.springerlink.com/content/77p4h0840310u677/
For reprints please contact Manfred Hartbauer (email:
Kind regards
Sonja Amoser
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Dr. Sonja Amoser
Steinrieglstraße 286
3400 Weidlingbach
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