Collaborative Research: Developmental and Receiver-Dependent Costs of Avian Signals

合作研究：鸟类信号的发育和依赖于接收者的成本。斯蒂芬·诺维基和威廉·A·西尔西在动物交流研究中的一个中心问题是，为什么信号提供可靠的信息，特别是在信号者和接收者的兴趣不同的情况下。理论表明，如果信号在某种程度上代价高昂，那么它们可能是可靠的。这项拟议的研究将这一理论应用于一个研究得很好的信号系统--鸟鸣。雌性鸣禽用雄性鸣叫声来判断未来配偶的质量。“营养压力假说”认为，发展歌曲的成本在男性的歌曲和他作为伴侣的质量之间产生了可靠的联系。因为歌曲的开发是昂贵的，任何经历早期压力(如食物短缺)的男性都会产生糟糕的歌曲和糟糕的整体表型，这使得歌曲质量成为衡量整体质量的可靠指标。以前的研究表明，早期的营养压力对控制歌曲的大脑区域的发育、男性学习歌曲的能力以及成年后体型的其他方面都有负面影响。拟议的研究将从三个方面扩展这项工作。首先，它将测试早期营养压力是否会影响男性的声乐表演，即他唱出对身体有挑战性的歌曲的能力。其次，这项研究将测试早期应激是否会影响成年鸟类的免疫系统质量，这一特征应该是雌性鸟类特别感兴趣的。第三，这项研究将询问早期压力是否也会影响女性对歌曲偏好的发展。歌曲也是相互竞争的雄性之间咄咄逼人的信号。在这种情况下，信号的可靠性可以通过接收器的积极响应所带来的代价来维持。如果这些信号也引发了接收者最激进的反应，那么这些信号就可以可靠地预测事态升级。先前的研究表明，“轻柔的歌曲”(非常安静地产生的歌曲)能够可靠地预测信号者的攻击性。这项拟议中的研究将测试轻柔的歌曲是否也可能像理论所表明的那样，激起接受者的攻击性反应。其次，研究将测试软歌曲是否会降低第三方个人从互动中获取信息的能力。第三，这项拟议的研究将调查信号匹配模式如何在攻击性互动中促进信号传递。这项拟议的研究将关于动物信号系统和配偶选择的理论和数据与关于大脑和行为发展的可检验假设结合在一起。事实证明，这一领域是招聘和培训妇女和少数群体科学家以及向公众传播如何开展科学研究的过程的有效平台。将开发一个互动网站，让6-12年级的学生模拟用鸣禽进行回放和学习实验。

Collaborative research: Developmental and receiver-dependent costs of avian signals.Stephen Nowicki & William A. SearcyA central question in the study of animal communication is why signals provide reliable information, especially in cases where the signaler has different interests from the receiver. Theory suggests that signals may be reliable if they are in some way costly. The proposed research applies this theory to a well studied signaling system, birdsong. Female songbirds use male song to judge the quality of prospective mates. The "nutritional stress hypothesis" proposes that the costs of song development produce a reliable link between a male's song and his quality as a mate. Because song development is costly, any male experiencing an early stress such as food shortage will produce both poor song and a poor overall phenotype, making song quality a reliable measure of overall quality. Previous work has shown that early nutritional stress has a negative impact on the development of the brain areas that control song, on the ability of males to learn songs, and on other aspects of adult phenotype such as body size. The proposed research will extend this work in three ways. First, it will test whether early nutritional stress affects a male's vocal performance, that is his ability to sing songs that are physically challenging to produce. Second, the research will test whether early stress affects the quality of the immune system of adult birds, a trait that should be of special interest to females. Third, the research will ask whether early stress also affects the development of song preferences in females. Song also serves as an aggressive signal between competing males. In this context, signal reliability may be maintained by costs imposed by the aggressive response of receivers. Signals can reliably predict escalation if those signals also elicit the most aggressive response by receivers. Previous work shows that "soft songs" (songs produced very quietly) reliably predict aggression on the part of the signaler. The proposed research will test whether soft song also is likely to provoke an aggressive response from receivers, as theory suggests. Second, research will test whether soft song reduces the ability of third party individuals to gain information from an interaction. Third, the proposed research will investigate how patterns of signal matching contribute to signaling in aggressive interactions. The proposed research integrates theory and data concerning animal signaling systems and mate choice with testable hypotheses about the development of brain and behavior. This area has proven to be an effective platform for recruiting and training women and minority scientists, and for disseminating the process of how science is done to the general public. An interactive website will be developed to allow students in grades 6-12 to simulate playback and learning experiments with songbirds.