Selection across the annual cycle: examining movement, colour, and behaviour

每年，数十亿只候鸟在繁殖地和越冬地之间飞行数千公里，一生中的大部分时间都远离它们的加拿大繁殖地。尽管如此，大多数研究都集中在相对较短的繁殖季节。然而，为了了解塑造这些鸟类生命的进化压力，我们需要涵盖整个年度周期的研究方法。我的研究重点是了解全年发生的事件如何相互作用，塑造鸟类的生态、生活史和进化。具体地说，我的目的是了解1)鸟类在繁殖和迁徙过程中何时、何地和如何蜕皮的蜕皮策略的演变；2)北美西部几种候鸟在完成向南的旅程之前中途停留在墨西哥季风区进行蜕皮的迁徙和蜕皮策略；3)全年发生的事件如何影响观赏羽毛颜色的演变。候鸟每年必须平衡三个能量密集的事件：繁殖、迁徙和换羽。虽然许多鸟类在时间上将这些事件分开，在繁殖后和迁徙之前完成蜕皮，但其他鸟类已经进化出独特的策略，这些策略在不同物种之间存在很大差异，但我们对可能塑造这些策略的生态或环境条件了解有限。例如，在干旱的西部，食物资源在夏末相当有限，因此，许多物种可能在完成繁殖后就开始迁徙，但在完成迁徙之前，它们会在墨西哥西北部/美国西南部停留数周进行换羽。这一时机与季风季相吻合，季风季将炎热的森林变成了郁郁葱葱的绿洲，拥有丰富的水果和昆虫，为蜕皮提供了完美的条件。鸟类在这一时期长出的羽毛不仅对高效飞行至关重要，而且对与竞争对手或潜在配偶交流信息也至关重要。然而，即使在这个地区，条件也可能有很大的差异，通过跟踪鸟类在整个迁徙和换羽过程中的情况，我们可以问到换羽位置和条件是如何影响羽毛颜色的。*确实，鸟类鲜艳的颜色吸引了科学家和公众的想象力。个体鸟类颜色的变化可以传达有关健康和状况的重要信息，雄性和雌性都可以用来确定潜在配偶或竞争对手的质量。我的研究计划的最终目标是使用一种创新的技术(分布在整个城市的射频识别喂鸟器)来跟踪整个年度周期中的个体鸟类，以探索色彩、在城市景观中的移动、社会网络、行为优势以及最终繁殖之间的联系。

Each year, billions of migratory birds travel thousands of kilometers between breeding and wintering grounds, spending most of their lives far from their Canadian breeding grounds. Despite this, most research has focused on the relatively short breeding season. Yet, to understand the evolutionary pressures shaping the lives of these birds, we need approaches that encompass research across the annual cycle. My research focuses on understanding how events occurring throughout the year interact to shape the ecology, life history, and evolution of birds. Specifically, my aim is to understand 1) the evolution of moult (feather replacement) strategies when, where, and how birds moult with respect to breeding and migration, 2) migration and moult strategies employed by several species of western North American migratory birds that stopover to moult in the Mexican monsoon region before completing their southward journey, and 3) how events occurring throughout the year influence the evolution of ornamental plumage colouration. *** Migratory birds must balance three energetically intensive events each year: breeding, migration, and moult. While many birds separate these events in time, completing moult just after breeding and before migration, others have evolved unique strategies that vary extensively across species yet, we have a limited understanding of the ecological or environmental conditions that may have shaped these strategies. For instance, in the arid West, food resources are quite limited in late summer and, likely as a result, many species begin migration just after the completion of breeding, but stop in Northwest Mexico/Southwest United States for several weeks to moult prior to completing their migration. This timing corresponds with the monsoon season, which transforms parched forests into a lush oasis with abundant fruit and insects perfect conditions for moult. The feathers that birds grow during this period will be critical not just for efficient flight, but for communicating information to rivals or potential mates. Yet, even within this region, conditions can vary extensively and by tracking birds throughout migration and moult, we can ask how moult location and conditions influence feather colouration. ***Indeed, the brilliant colours of birds capture the imagination of scientists and the public alike. Variation in the colour of individual birds can convey important information on health and condition and is used by both males and females to ascertain the quality of potential mates or rivals. The final goal of my research program is to use an innovative technique (radio frequency identification enabled bird feeders distributed across a city) to track individual birds throughout the entire annual cycle to explore the connections between colouration, movement across an urban landscape, social networks, behavioural dominance, and ultimately reproduction.