Department of Biology, Carleton University Ottawa, Ontario, Canada.
PLoS One. 2013 Jul 23;8(7):e69247. doi: 10.1371/journal.pone.0069247. Print 2013.
Phenotypic plasticity can be adaptive when phenotypes are closely matched to changes in the environment. In crickets, rhythmic fluctuations in the biotic and abiotic environment regularly result in diel rhythms in density of sexually active individuals. Given that density strongly influences the intensity of sexual selection, we asked whether crickets exhibit plasticity in signaling behavior that aligns with these rhythmic fluctuations in the socio-sexual environment. We quantified the acoustic mate signaling behavior of wild-caught males of two cricket species, Gryllus veletis and G. pennsylvanicus. Crickets exhibited phenotypically plastic mate signaling behavior, with most males signaling more often and more attractively during the times of day when mating activity is highest in the wild. Most male G. pennsylvanicus chirped more often and louder, with shorter interpulse durations, pulse periods, chirp durations, and interchirp durations, and at slightly higher carrier frequencies during the time of the day that mating activity is highest in the wild. Similarly, most male G. veletis chirped more often, with more pulses per chirp, longer interpulse durations, pulse periods, and chirp durations, shorter interchirp durations, and at lower carrier frequencies during the time of peak mating activity in the wild. Among-male variation in signaling plasticity was high, with some males signaling in an apparently maladaptive manner. Body size explained some of the among-male variation in G. pennsylvanicus plasticity but not G. veletis plasticity. Overall, our findings suggest that crickets exhibit phenotypically plastic mate attraction signals that closely match the fluctuating socio-sexual context they experience.
表型可塑性在表型与环境变化密切匹配时是适应性的。在蟋蟀中，生物和非生物环境的节奏波动经常导致有性活动个体密度的昼夜节律。鉴于密度强烈影响性选择的强度，我们想知道蟋蟀是否表现出与社会性行为环境中这些节奏波动相适应的信号行为可塑性。我们量化了两种蟋蟀，Gryllus veletis 和 G. pennsylvanicus 的野生雄性的声学交配信号行为。蟋蟀表现出表型可塑性的交配信号行为，大多数雄性在野生环境中交配活动最高的白天时间里，更频繁、更有吸引力地发出信号。大多数雄性 G. pennsylvanicus 更频繁、更响亮地鸣叫，具有更短的脉冲间隔、脉冲周期、鸣叫持续时间和鸣叫间隔，并且在野生环境中交配活动最高的白天时间里载波频率略高。同样，大多数雄性 G. veletis 更频繁地鸣叫，每声鸣叫的脉冲更多，脉冲间隔、脉冲周期和鸣叫持续时间更长，鸣叫间隔更短，载波频率更低，在野生环境中交配活动的高峰期。信号可塑性的雄性间变异性很高，一些雄性表现出明显的适应不良的信号方式。体型解释了 G. pennsylvanicus 可塑性中部分雄性间的变异性，但不能解释 G. veletis 可塑性中雄性间的变异性。总体而言，我们的研究结果表明，蟋蟀表现出与它们所经历的波动的社会性行为环境密切匹配的表型可塑性交配吸引信号。
