Song recognition in the grasshopper Chorthippus biguttulus is not impairedby shortening song signals: implications for neuronal encoding

The communication signals in many grasshopper species are composed of multi ple repetitions of highly stereotyped subunits, and thus provide redundancy . In a behavioural paradigm, we tested the ability of males of the grasshop per Chorthippus biguttulus to recognize shortened versions of the communica tion signals of conspecific females. Males reliably responded to a three-su bunits signal (250 ms), i.e. to a signal of less than a quarter of the natu ral duration. This performance is remarkable in view of the substantial ada ptation and the variability present in the spiking responses of auditory in terneurones. These behavioural results will impose constraints for investig ating possible encoding mechanisms used by the grasshoppers' auditory syste m.