Department of Biology, Carleton University, Ottawa, Ontario, Canada.
PLoS One. 2013;8(3):e60356. doi: 10.1371/journal.pone.0060356. Epub 2013 Mar 20.
Theoretically, sexual signals should provide honest information about mating benefits and many sexually reproducing species use honest signals when signalling to potential mates. Male crickets produce two types of acoustic mating signals: a long-distance mate attraction call and a short-range courtship call. We tested whether wild-caught fall field cricket (Gryllus pennsylvanicus) males in high condition (high residual mass or large body size) produce higher effort calls (in support of the honest signalling hypothesis). We also tested an alternative hypothesis, whether low condition males produce higher effort calls (in support of the terminal investment hypothesis). Several components of long-distance mate attraction calls honestly reflected male body size, with larger males producing louder mate attraction calls at lower carrier frequencies. Long-distance mate attraction chirp rate dishonestly signalled body size, with small males producing faster chirp rates. Short-range courtship calls dishonestly reflected male residual mass, as chirp rate and pulse rate were best explained by a curvilinear function of residual mass. By producing long-distance mate attraction calls and courtship calls with similar or higher effort compared to high condition males, low condition males (low residual mass or small body size) may increase their effort in current reproductive success at the expense of their future reproductive success, suggesting that not all sexual signals are honest.
从理论上讲,性信号应该提供有关交配利益的诚实信息,许多有性繁殖的物种在向潜在配偶发出信号时会使用诚实的信号。雄性蟋蟀会产生两种类型的声学交配信号:远距离求偶吸引叫声和近距离求爱叫声。我们测试了在高条件(高剩余质量或大体型)下的野生秋季田蟋蟀(Gryllus pennsylvanicus)雄性是否会发出更高的叫声(支持诚实信号假说)。我们还测试了另一个假说,即低条件雄性是否会发出更高的叫声(支持终端投资假说)。远距离求偶吸引叫声的几个组成部分诚实地反映了雄性的体型,体型较大的雄性会发出更低载波频率的响亮求偶吸引叫声。远距离求偶叫声的啁啾率不诚实地反映了雄性的体型,小雄性发出的啁啾率更快。近距离求爱叫声不诚实地反映了雄性的剩余质量,因为啁啾率和脉冲率最好用剩余质量的曲线函数来解释。低条件雄性(低剩余质量或小体型)通过发出与高条件雄性相似或更高的远距离求偶吸引叫声和求爱叫声,可能会增加其当前生殖成功的努力,而牺牲其未来的生殖成功,这表明并非所有的性信号都是诚实的。