Lailvaux Simon P, Irschick Duncan J
Laboratory for Functional Morphology, University of Antwerp, Universiteitsplein 1, B-2610 Antwerp, Wilrijk, Belgium.
Am Nat. 2007 Oct;170(4):573-86. doi: 10.1086/521234. Epub 2007 Aug 6.
Despite the empirical and theoretical attention paid to the role of sexual signals in resolving agonistic interactions between conspecific males, few studies have applied a comparative perspective, particularly across species that vary in combat intensity. We investigated the relative roles of a male sexual signal (dewlap size) and whole-organism performance capacity (bite force) on male combat outcomes in nine species of Caribbean Anolis lizards that differ markedly in territoriality, as indicated by sexual size dimorphism. We found that (1) dewlap size was generally an honest signal of bite force in dimorphic but not less dimorphic species; (2) maximum bite force consistently predicted male combat success in dimorphic but not less dimorphic species; (3) in contrast to a priori predictions, dewlap size significantly predicted male combat success in less dimorphic but not dimorphic species; and (4) the incidence of biting but not dewlapping increases as species become more dimorphic. These findings suggest that more dimorphic (and hence more territorial) species escalate to biting during fights more readily compared with less territorial species. The ecological and behavioral qualities of species may therefore modify both the shape and the size of sexually selected traits as well as the nature of the information those traits convey.
尽管对于性信号在解决同种雄性间的争斗性互动中所起的作用，已经有了实证和理论方面的关注，但很少有研究采用比较的视角，尤其是在战斗强度不同的物种之间。我们研究了一种雄性性信号（喉扇大小）和整个生物体的性能能力（咬合力）在九种加勒比安乐蜥雄性战斗结果中的相对作用，这些物种在两性异形方面差异显著，而两性异形可作为领地性的指标。我们发现：（1）在两性异形的物种中，喉扇大小通常是咬合力的诚实信号，但在两性异形程度较低的物种中并非如此；（2）最大咬合力始终能预测两性异形物种中雄性战斗的成功，但在两性异形程度较低的物种中则不然；（3）与先验预测相反，喉扇大小在两性异形程度较低的物种中能显著预测雄性战斗的成功，但在两性异形的物种中则不能；（4）随着物种两性异形程度的增加，咬而不是展示喉扇的发生率会上升。这些发现表明，与领地性较弱的物种相比，两性异形程度更高（因此领地性更强）的物种在战斗中更容易升级为咬人。因此，物种的生态和行为特征可能会改变性选择特征的形态和大小，以及这些特征所传达信息的性质。
