Sound Fields and Mate Choice

9723521布拉德伯里许多动物发声系统的自适应设计受到提高呼叫幅度和将这些声音有效地投射到预期接收者的方向的选择的强烈影响。在一些系统中，特定的结构对体积和方向性都有深远的影响。在许多不同脊椎动物的发声系统中，一个这样的结构就是充气气囊，它看起来像是一个辅助器官。虽然这种适应显然是这些系统的一个重要特征，但人们对气囊如何影响音量和方向性知之甚少。利用新开发的多声道记录技术，本研究将重点研究几种逗逗松鸡，以澄清显示叫声幅度、叫声的方向性和声囊的形状和数量之间的关系。我们之所以选择松鸡，是因为不同物种在气囊位置和操作方面存在着有趣的差异。一些松鸡有成对的外部气囊。初步证据表明，雄性鼠尾松鸡可能会使用它们的双囊系统将其交配展示的某些部分传输给雌性，而不考虑雄性的相对方位。这些数据也将被用来重新检验振幅在雌性鼠尾松鸡交配选择中的作用。鼠尾松鸡是研究得最好的系统之一，在这个系统中，雌性完全根据雄性表型来选择配偶；叫声幅度是唯一仍然抵制适当测量的参数。我们现在有办法进行这些测量并完成分析。我们希望这项比较研究将产生可以应用于其他群体的声囊功能的模型，更广泛地说，有助于我们理解幅度和方向性在雌性选择偏向交配系统中的重要性。

9723521 Bradbury The adaptive design of many animal sound production systems is strongly influenced by selection for increased call amplitude and efficient projection of those sounds in the direction of intended recipients. In some systems, specific structures have profound effects on both volume and directionality. One such structure which appears as an accessory organ in the sound production systems of many diverse vertebrate groups is an inflatable air sac. While this adaptation is clearly an important feature of these systems, very little is known about how air sacs affect sound volume and directionality. Using newly developed multitrack recording techniques, this study will focus on several species of lekking grouse to clarify the relationship between display call amplitude, the directionality of the call, and the shape and number of vocal sacs. We have chosen grouse because of the degree of interesting variations in air sac position and operation in the different species. Some grouse have paired external air sacs. Preliminary evidence suggests that sage grouse males may use their two-sac system to beam certain components of their mating displays toward females regardless of the males' relative orientation. These data will also be used to re-examine the role of amplitude in mate choice of female sage grouse. Sage grouse leks are one of the best studied systems in which females choose mates solely on the basis of male phenotype; call amplitude is the only parameter which has remained resistant to proper measurement. We now have the means to make these measurements and complete the analysis. Our hope is that this comparative study will generate models that can be applied to vocal sac function in other groups and, more broadly, contribute to our understanding of the importance of amplitude and directionality in female choice biased mating systems.