Synchrony during acoustic interactions in the bushcricket Mecopoda ‘Chirper’ (Tettigoniidae:Orthoptera) is generated by a combination of chirp-by-chirp resetting and change in intrinsic chirp rate
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In several bushcricket species, individual males synchronise their chirps during acoustic interactions. Synchrony is imperfect with the chirps of one male leading or lagging the other by a few milliseconds. Imperfect synchrony is believed to have evolved in response to female preferences for leading chirps. We investigated the mechanism underlying synchrony in the bushcricket species Mecopoda ‘Chirper’ from Southern India using playback experiments and simulations of pairwise interactions. We also investigated whether intrinsic chirp period is a good predictor of leading probability during interactions between males. The mechanism underlying synchrony in this species differs from previously reported mechanisms in that it involves both a change in the oscillator’s intrinsic rate and resetting on a chirp-by-chirp basis. The form of the phase response curve differs from those of previously reported firefly and bushcricket species including the closely related Malaysian species Mecopoda elongata. Simulations exploring oscillator properties showed that the outcome of pairwise interactions was independent of initial phase and alternation was not possible. Solo intrinsic chirp period was a relatively good predictor of leading probability. However, changing the intrinsic period during interactions could enable males with longer periods to lead during acoustic interactions.
KeywordsMecopoda Synchrony Phase response curve Song oscillator Bushcricket
Phase response curve
Sound pressure level
We are grateful to the Ministry of Environment and Forests, Government of India for funding this project. We thank Sumit Dhole for help with some of the recordings. We also thank Heiner Römer and Manfred Hartbauer for interesting discussions. We thank two anonymous reviewers for their insightful comments and suggestions. The experiments comply with the legal principles of animal care and animal welfare of the Government of India.
- Batschelet E (1981) Circular statistics in biology. Academic, New YorkGoogle Scholar
- Buck J (1988) Synchronous flashing of fireflies. II. Q Rev Biol 13:301–304Google Scholar
- Forrest TG, Ariaratnam J, Strogatz SH (1998) Synchrony in cricket calling songs: models of coupled biological oscillators. In: Proceedings of the 16th International Congress on Acoustics and the 135th meeting of the Acoustical Society of America, Seattle, USA, pp 689–690Google Scholar
- Frank H, Altheon SC (1994) Testing hypotheses about population means. In: Statistics concepts and applications. Cambridge University Press, Cambridge, pp 380–452Google Scholar
- Jones MDR (1974) The effect of acoustic signals on the chirp rhythm in the bushcricket Pholidoptera griseoaptera. J Exp Biol 61:345–355Google Scholar
- Nityananda V, Balakrishnan R (2006) A diversity of songs among morphologically indistinguishable katydids of the genus Mecopoda (Orthoptera: Tettigoniidae) from Southern India. Bioacoustics 15:223–250Google Scholar
- Römer H, Hedwig B, Ott SR (1997) Proximate mechanism of female preference for the leader male in synchronising bushcrickets (Mecopoda elongata). In: Elsner N, Wässle H (eds) Proceedings of the 25th Göttingen neurobiology conference, Thieme, Stuttgart, 322 ppGoogle Scholar
- West-Eberhard MJ (1984) Sexual selection, competitive communication and species-specific signals in insects. In: Lewis T (ed) Insect communication. Academic, London, pp 283–324Google Scholar