DISSERTATION RESEARCH: Forging a Context for Female Mate Choice for Carotenoid Ornaments

论文研究：为类胡萝卜素装饰品的女性择偶创造背景

• 批准号: 1501560
• 负责人: Geoffrey Hill
• 金额: $ 1.92万
• 依托单位: Auburn University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-07-01 至 2017-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1501560&HistoricalAwards=false
• 关键词: DISSERTATION; RESEARCH; Forging; Context; Female

The overarching goal of this research project is to advance understanding of the evolution of animal ornamentation. Birds feature some of the most elaborate songs, dances, and colors of the animal kingdom, and such displays are generally accepted to have evolved in response to female preferences during mate choice. However, the specific processes that have shaped the ornamental traits remain contentious. In particular, current theory proposes that the yellow-to-red coloration in the ornaments of many bird species is an honest signal of quality, but the mechanisms linking ornament expression to quality, and hence the information content that ornaments present to choosing females, remain unclear. This research project will provide critical tests of how colorful pigments relate to the quality of both colored ornaments and physiological condition in a songbird species, the domestic canary (Serinus canaria). An additional set of experiments will then investigate how the two conspicuous signals of the male canary--brilliant coloration and complex song--interact to shape female mate choice. Using a species that is well-adjusted to captivity enables particularly fine control over experimental variables without subjecting the birds to cage stress, and further allows for a suite of outreach activities using live canaries as "science ambassadors" both to hobbyist canary breeders nationwide and young students across the state of Alabama.While many behavioral studies have examined sexual selection for carotenoid-based coloration, there is no consensus for how carotenoid pigments link to signal honesty and how condition-dependent signals shape female preferences. This research project comprises two complementary sets of experiments assessing both the mechanistic basis of signal honesty and the ultimate function of color signals. The research will address these questions with tight experimental control using the highly amenable captive system of the domestic canary (Serinus canaria). Initial experiments will examine the mechanistic basis for condition-dependence in carotenoid-based ornaments by testing fundamental assumptions about the role of allocation tradeoffs in maintaining signal honesty. Specifically, the researchers will use canaries with knockout mutations that eliminate carotenoid absorption or allocation to examine the benefit of circulating carotenoids and the potential cost of their allocation to plumage in a controlled manner that is not possible in other systems. While these experiments will yield information about the proximate mechanisms that maintain signal honesty, bridging the gap between mechanism and function will greatly advance the importance of this core research to understanding animal behavior. Therefore, the second set of experiments will use a novel mate-choice experimental design with tight control over male display phenotype to examine whether the condition-dependent expression of carotenoid coloration is the target of female preference. These tests will establish the ultimate behavioral context for the mechanism studied in the first experiments by assessing how carotenoid-based plumage coloration impacts mate choice as a component of the overall multimodal songbird display.

该研究项目的总体目标是促进对动物进化的理解。鸟类拥有动物王国中最精致的歌曲、舞蹈和颜色，人们普遍认为，这些表演是在雌性择偶时进化而来的。然而，形成观赏性状的具体过程仍然存在争议。特别是，目前的理论认为，许多鸟类装饰品中的黄色到红色是质量的诚实信号，但将装饰品表达与质量联系起来的机制，以及装饰品对选择雌性的信息内容，仍然不清楚。这项研究项目将提供关键的测试如何彩色色素与质量的彩色装饰品和生理条件的鸣禽物种，国内金丝雀（Serinus canaria）。另外一组实验将研究雄性金丝雀的两个明显信号--鲜艳的色彩和复杂的歌声--如何相互作用来塑造雌性金丝雀的配偶选择。使用一种适应圈养环境的物种能够特别精细地控制实验变量，而不会使鸟类受到笼子压力，并进一步允许使用活金丝雀作为“科学大使”的一系列推广活动，既可以向全国范围内的金丝雀饲养爱好者和亚拉巴马州的年轻学生推广。对于类胡萝卜素色素如何与诚实信号联系起来，以及依赖条件的信号如何塑造女性偏好，还没有达成共识。该研究项目包括两组互补的实验，评估信号诚实的机械基础和颜色信号的最终功能。这项研究将解决这些问题，严格的实验控制使用高度顺从的圈养系统的国内金丝雀（Serinus canaria）。最初的实验将检查条件依赖的机械基础，类胡萝卜素为基础的装饰品，通过测试的基本假设分配权衡的作用，保持信号的诚实。具体来说，研究人员将使用具有消除类胡萝卜素吸收或分配的敲除突变的金丝雀来检查循环类胡萝卜素的益处以及以其他系统中不可能的受控方式分配到羽毛的潜在成本。虽然这些实验将产生有关维持信号诚实性的近似机制的信息，但弥合机制和功能之间的差距将大大提高这一核心研究对理解动物行为的重要性。因此，第二组实验将使用一种新的择偶实验设计，严格控制雄性展示表型，以检查类胡萝卜素着色的条件依赖性表达是否是雌性偏好的目标。这些测试将建立最终的行为背景的机制研究在第一个实验中，通过评估如何类胡萝卜素为基础的羽毛着色影响配偶的选择作为一个组成部分的整体多模态鸣禽显示。