Condition-dependent signal reception: limitations and functions of carotenoids in avian color vision

动物使用各种各样的信号进行交流（如歌声、颜色），其中许多都是它们作为配偶或对手的价值的诚实指标。然而，动物感知世界和接收传输信号的方式也可能与它们的质量（如健康、状况）有关，这种对信号接收的控制可能会影响动物通信系统的进化速度和方向。这项研究将包括调查鸣禽（家雀，Carpodacus mexicanus）的颜色视觉感觉系统在多大程度上受到环境因素的影响，包括饮食、疾病和光照，并影响关键的行为任务，如食物选择和配偶选择，这两者都涉及到颜色偏好。色觉的条件依赖性将通过跟踪视网膜上类胡萝卜素（例如胡萝卜的橙色色素）的种类和数量的积累来探索，在视网膜上，它们被认为是过滤光线，保护眼睛免受光损伤，并调节颜色视觉灵敏度。这种方法提供了色觉和颜色产生之间的关键分子联系，在家雀和许多其他动物中，颜色产生以红色、橙色和黄色类胡萝卜素的形式发生，这些类胡萝卜素在羽毛中的供应也是有限的，并且依赖于条件。本研究中采用的生化、营养和行为方法将丰富对以下方面的理解：(a)动物抗氧化营养素带来的一系列益处，(b)动物交流背景下的资源分配和权衡，以及(c)在共同化学货币中追踪动物性特征和偏好的共同进化机制。实地研究的城市性质也提供了让当地教师和儿童参与数据收集和科学培训的机会，以便他们可以直接测试人类侵犯通讯系统的影响和适应沙漠的生物的生存能力。

Animals use a diversity of signals for communication (e.g. songs, colors), many of which are honest indicators of their worth as a mate or rival. However, the ways that animals perceive the world and receive transmitted signals may also be linked to their quality (e.g. health, condition), and such control of signal reception could impact the evolutionary pace and directions of animal communication systems. This research will involve investigations of the degree to which the color-visual sensory system of a songbird species (the house finch, Carpodacus mexicanus) is impacted by environmental factors, including diet, disease, and light exposure, and affects critical behavioral tasks like food selection and mate selection, both of which involves color preferences. Condition-dependence of color vision will be explored by tracking accumulation of the types and amounts of carotenoid pigments (e.g. the orange colorants of carrots) dedicated to the retina, where they are thought to filter light, protect the eye from photodamage, and tune color visual sensitivity. This approach provides a key molecular link between color vision and color production, which in house finches and many other animals occurs in the form of red, orange, and yellow carotenoid pigments whose supplies in feathers are also limited and condition-dependent. The biochemical, nutritional, and behavioral approaches taken in this research will enrich understandings of (a) the suite of benefits conferred by antioxidant nutrients in animals, (b) resource allocations and trade-offs in the context of animal communication, and (c) the coevolutionary mechanisms governing sexual traits and preferences in animals, tracked in a common chemical currency. The urban nature of the field research also affords the opportunity to involve local schoolteachers and children in data collection and science training, so that they may test first-hand the impacts of human encroachment on the communication system and viability of a desert-adapted organism.