CAREER: Song and Plumage in the House Finch: A Study of Signal Content in a Multiple-Signal System

IBN-9722171 希尔 鲜艳的色彩和优美的歌声是鸟类最显著的特征之一，但这些特征对进化生物学家来说是一个悖论。 这些看似浪费能量、让个体暴露在掠食者面前的华而不实的特征，是如何通过自然选择进化而来的？自然选择是一个应该促进生存和繁殖的过程。 对这个问题的普遍接受的答案是，这些装饰性特征是通过性选择产生的，这是一个通过配偶吸引或配偶防御来促进获得配偶的过程。 在观赏性状的进化过程中，雌性的择偶行为是一个重要的选择因子，但雌性为什么要选择这些性状呢？ 对这个谜团的一种解释是，装饰性特征是男性品质的真实信号。 通过选择有发达装饰的雄性，雌性选择了比平均水平更好的雄性。 然而，情节变得更加复杂，因为大多数动物物种都有不止一个而是多个装饰性特征。 例如，大多数种类的鸣禽既有五颜六色的羽毛又能唱歌。 这项研究将研究的歌曲和色彩鲜艳的羽毛的功能，在房子雀，一个常见的后院鸟发现在整个美国大陆的研究将测试的想法，女性房子雀获得不同的信息男性质量从不同的观赏性状。 家雀的彩色羽毛是类胡萝卜素色素的结果，鸟类必须从他们的饮食中获得。 因此，羽毛的亮度是雄性在羽毛生长时的营养状况的函数。 歌曲发展的控制还不太清楚，但它也可能依赖于营养。 这项工作的重点是男性质量的两个措施：抗病能力和父母的努力。通过结合对圈养鸟类和野生鸟类的观察进行的实验，该研究将确定雄性家雀的歌声和装饰羽毛颜色之间的关系 两种不同类型的疾病：球虫，一种慢性肠道寄生虫，以及结膜炎，一种快速发作的眼睛和上呼吸道系统细菌感染。 预测是，在显示时产生的歌曲将是短时间快速反应疾病的更好指标。 相比之下，羽毛，这是生长在六个星期的时间，几个月前，它被用于显示，将是一个更好的预测慢性感染。 歌曲和羽毛也可能传达不同的信息，男性提供年轻的能力。 这项研究将是第一个同时研究多个观赏性状的功能，并将提供新的见解，性选择的过程和动物的观赏性状的进化。 雄性动物的显著观赏特征可能会向雌性动物传递关于未来配偶的信息，这是一个直观的吸引人的假设，许多学生（广义上-包括高中生，科学教师，本科生和成人教育学生）都认为这是令人信服的。该研究项目将纳入一个教育重点，涉及上述学生群体的参与。家雀是一种理想的物种，用于向学生介绍野外生物学的研究-它们体积小，温顺，易于捕捉，颜色鲜艳，易于量化，习惯于人类，并在校园的显眼位置筑巢。此外，在美国几乎每个校园都能找到家雀，部分研究亦会与中学教师一起开发科学习题，让学生体验真实的科学探究的挑战与刺激。

IBN-9722171 Hill Bright colors and beautiful song are among the most conspicuous features of birds, but these traits pose a paradox for evolutionary biologists. How could such gaudy traits, which seem to waste energy and expose individuals to predators, have evolved by natural selection, a process that should promote survivorship and reproduction? The generally accepted answer to this question is that such ornamental traits arose through sexual selection, a process that promotes access to mates either through mate attraction or mate defense. Female mate choice has been shown to be an important selective agent in the evolution of ornamental traits, but why should females choose such traits? One explanation for this riddle is that ornamental traits serve as honest signals of male quality. By choosing males with well-developed ornaments, females choose better-than-average males. The plot thickens further, though, in that most species of animals have not one but multiple ornamental traits. For instance, most species of songbirds have both colorful plumage and song. This research will study the function of song and colorful plumage in the House Finch, a common backyard bird found throughout the contintental U.S. Studies will test the idea that female House Finches gain different information about male quality from different ornamental traits. Colorful plumage in the House Finch is a result of carotenoid pigments, which birds must obtain from their diet. Thus, plumage brightness is a function of the nutritional condition of males at the time when feathers are grown. The control of song development is less well understood, but it may also be dependent on nutrition. The focus of this work is on two measures of male quality: disease resistance and parental effort. Using a combination of experiments conducted with captive birds and observations of wild birds, the study will determine how song and ornamental plumage coloration of male House Finches relate to two different types of disease: coccidia, a chronic intestinal parasite, and conjunctivitis, a bacterial infection of the eye and upper respiratory system with rapid onset. The prediction is that song, which is produced at the time of display, will be a better indicator of fast- acting disease of short duration. In contrast, plumage, which is grown over a six-week period, months before it is used in display, will be a better predictor of chronic infection. Song and plumage may also convey different information about the ability of males to provision young. This research will be among the first to simultaneously investigate the function of multiple ornamental traits, and will provide new insight into the process of sexual selection and the evolution of ornamental traits in animals. The idea that conspicuous ornamental traits in male animals might convey information about prospective mates to females is an intuitively appealing hypothesis that many students (in the broad sense - including high school students, science teachers, undergraduates and adult education students) find compelling. The research project will incorporate an educational focus involving participation by the previously-mentioned student populations. The House Finch is an ideal species for studies intended to introduce students to field biology - they are small, docile, easy to catch, have bright colors that are easy to quantify, are habituated to people, and nest in conspicuous locations on campus. In addition, House Finches are found in nearly every schoolyard in the U.S., and part of this study will also develop science exercises with high school teachers, and allow students to experience the challenge and excitement of real scientific investigation.