Abstract
Many acoustic animals exhibit temporally structuredchorusing, and in some cases, groups of calling malesdisplay elaborate forms of synchrony and/or alternation. Suchtemporal structure has traditionally been explained as an adaptationby which chorusing males preserve critical call features,maximize the attractiveness of their local group to females,or improve their ability to detect, evaluate, and/orevade rival males or predators. However, an alternative possibilityis that synchrony and alternation simply emerge as incidentalby-products of basic pairwise signal interactions betweenmale neighbors. Thus, females may not be influencedby synchrony and alternation, and males may not benefit perse from the very chorus that they collectively produce. Westudied chorusing in the bushcricket Ephippiger diurnus, aspecies that sings in both synchrony and alternation, by presentingnatural and modified chorus stimuli to females in aseries of playback tests. We found that females respondedreadily to the various stimuli, but we did not observe an elevatedresponse to the natural chorus stimuli in any experimentor in any of the several E. diurnus populations tested. Ourresults demonstrate for the first time how elaborate forms ofsynchrony and alternation can represent emergent propertiesof choruses as opposed to specialized group displays that affordparticular advantages to the individual singers.