Fig. 2.

Change in tuning of cricket steering during phonotaxis. Steering responses were analyzed toward series of chirps with different SPs (see bottom of figure). (A, blue lines) Crickets steered toward species-specific SP34 chirps but showed only minor responses toward nonattractive chirps with either short (18-ms) or long (98-ms) SP that did not correspond to the normal song. (A, red lines) Steering behavior toward the same nonattractive chirps when these were inserted into a sequence of cricket song. The animals made increased steering responses toward SP18 and SP98 chirps (steering velocity averaged for 180 chirps for blue and red curves, respectively). (B, blue lines) Tuning of cricket phonotactic steering toward chirps with different SP when these were presented on their own. Phonotaxis is tuned to SP34 and animals do not respond toward chirps with short or long SPs. (B, red lines) Tuning of phonotactic steering toward nonattractive chirps inserted into a sequence of SP34 chirps. Crickets steered toward chirps with SP of 50–98 ms with the same magnitude as to attractive SP34 chirps. Steering increased less intensely toward inserted chirps with SP of 10–26 ms. Data are pooled from 10 animals, error bars indicate the SEM.