Research Starter Grant

许多物种的雄性会做出壮观的求爱表演来吸引雌性交配。雌性可能更喜欢有精心展示的雄性，因为这些展示可以作为一种信号，传递雄性作为配偶的“质量”的信息。雄性产生这些信号，但这些信号必须通过环境传播才能到达雌性。环境会影响信号的传输：例如，声音在某些环境中比其他环境传播得更好，环境光会影响颜色的呈现。因此，到达雌性的信号既取决于雄性发出的信号，也取决于传递信号的环境。这可能是雄性选择具有良好传输特性的展示位置（例如，良好的照明或良好的声学）来增加其展示的吸引力。在这个研究项目中，大艾草松鸡（Centrocercus urophasianus）将被用作一个模型系统来研究声环境在影响雄性展示行为和雄性说服雌性交配成功方面的重要性。在繁殖季节，雄性艾草松鸡聚集在称为“leks”的展示场地上，并竞争建立展示区域。在它们的领地上，雄性会发出壮观的声音，雌性在选择配偶时也会评估这些声音。雄性显示区域的“音质”在整个过程中是可变的，这种变化会影响雌性感知到的发声的音高和响度；因此，一个领地的音质可能会影响住在那里的雄性的交配成功率。声学定位系统（ALS）将用于绘制男性领地的详细地图和偏好展示地点的位置。渐冻声是一种将声音记录在多个麦克风上的技术，通过声音到达每个麦克风的时间差异来重建声源的位置。这些ALS数据将与雄性交配成功的测量结果和雄性展示地点的声学质量相结合，以验证两个假设：1)领地的声学质量影响居住雄性的吸引力，2)在其领地内，雄性偏好在信号传输更好的地方展示。这个项目的结果将有助于我们理解环境如何影响动物的声音交流和求爱。这个项目将包括发展和改进研究声学通信和领土行为的方法，这些方法可以被许多其他研究人员使用。在此过程中，本研究将为加州大学戴维斯分校的本科生、研究生和博士后研究人员提供研究和培训机会。最后，艾草松鸡被联邦政府认定为“值得关注的物种”，艾草松鸡栖息地的丧失和人为噪音的增加可能是它们数量下降的原因。这项工作的结果将增加我们对不同栖息地特征如何影响艾草松鸡繁殖的理解；这些信息将为未来决定艾草松鸡栖息地的适宜性提供信息。此外，这个项目的结果将增加我们对声音如何在艾草松鸡栖息地传播的理解，并将为关于人类产生的噪音如何影响艾草松鸡的声音传播和繁殖的辩论提供信息。

Males of many species produce spectacular courtship displays to attract females to mate. Females may prefer males with elaborate displays because these displays act as signals, conveying information about the male's "quality" as a mate. Males produce these signals, but the signals must transmit through the environment to reach the female. The environment can affect signals during transmission: for example, sound carries better in some environments than others and ambient light can affect how colors appear. Therefore, the signal that reaches the female depends both on what is sent by the male and the environment through which it is transmitted. This may select for males that choose display locations with good transmission properties (e.g. good lighting or good acoustics) to increase the attractiveness of their display. In this research project, greater sage grouse (Centrocercus urophasianus) will be used as a model system to examine the importance of the acoustic environment in influencing both male display behaviors and male success in convincing females to mate. During the breeding season, male sage grouse aggregate on display grounds called "leks" and compete to establish display territories. On their territories, males produce spectacular vocalizations, which females assess when choosing their mates. The "acoustic quality" of male display territories is variable across the lek, and this variation will impact the pitch and loudness of vocalizations perceived by females; for this reason, the acoustic quality of a territory may affect the mating success of the resident male. An Acoustic Localization System (ALS) will be used to create detailed maps of male territories and the locations of favored display sites. ALS is a technique whereby a sound is recorded on multiple microphones, and the difference in the time at which the sound reaches each microphone is used to reconstruct the location of sound source. This ALS data will be combined with measurements of male mating success and the acoustic quality of male display sites to test two hypotheses: 1) that the acoustic quality of a territory impacts the attractiveness of the resident male, and 2) that within their territories, males preferentially display from locations that improve signal transmission.The results of this project will contribute to our understanding of how the environment affects acoustic communication and courtship in animals. This project will involve the development and refinement of methods for studying acoustic communication and territorial behaviors that can be used by many other researchers. In the process, this research will provide research and training opportunities to undergraduates, graduate students and postdoctoral researchers at the University of California, Davis. Finally, greater sage grouse are federally recognized as a "species of concern", and both the loss of sage-grouse habitat and the increase in human-produced noise are likely causes of their declining numbers. Results from this work will increase our understanding of how different habitat characteristics affect reproduction in sage grouse; this information will inform future decisions about the suitability of habitat for sage grouse. In addition, results from this project will increase our understanding of how sound propagates through the sage-grouse habitat, and will inform the debate on how human-produced noise impacts acoustic communication and reproduction on the lek.