Evolutionary drivers of variation in bat migration

许多动物迁徙，完成了从相对较短的旅行到令人敬畏的大陆规模的旅行。迁徙运动的变异在物种内很常见，而且通常与其他性状的变异有关。例如，长途候鸟的体型可能使他们比同物种的短途候鸟更有效率地旅行。研究不同距离迁徙的动物之间的差异可以帮助我们更好地理解导致迁徙进化的因素。许多蝙蝠物种迁徙，但蝙蝠迁徙的研究几乎没有其他种群那么多。由于蝙蝠是夜间活动的，很难观察到，跨越空间和时间追踪它们是具有挑战性的。因此，我们对它们的基本运动知之甚少，令人惊讶。这是一个问题，因为许多北美蝙蝠处于危险之中，了解它们的活动对保护它们很重要。之前的研究，包括我自己的工作，已经表明蝙蝠在迁徙活动中的物种内差异是常见的，但推动这种差异的因素在很大程度上是未知的。调查这一知识鸿沟是我的长期研究目标。*我的研究计划有三个直接目标。首先，我和我的学生将研究蝙蝠在迁徙运动、形态和生活史类别(如年龄、性别)方面的变化之间的联系。要做到这一点，我们需要(2)继续描述基本的蝙蝠迁徙运动，(3)改进我们用来了解蝙蝠迁徙的技术。*之前，我曾使用毛皮样本的化学(稳定氢同位素)分析来研究蝙蝠迁徙。我们将继续使用和改进这项技术，并将开发一种不太常见的方法-锶同位素分析-用于蝙蝠。最后，我们将使用Motus野生动物跟踪系统，这是一个允许研究人员在迁徙动物移动时跟踪它们的倡议。这三种方法将使我们能够以不同的尺度和不同的决议追踪移民。我们将能够以以前不可能的方式将蝙蝠的迁徙运动与其他身体特征联系起来。我的研究团队将在北美各地(包括纽芬兰当地)工作，并使用活蝙蝠和博物馆标本。*由于蝙蝠与其他小型飞行候鸟(如鸟类、昆虫)非常不同，这项工作将增加我们对迁徙理论的理解的新维度。我建议研究迁徙和形态变异之间的联系，这是一个长期计划的第一步，该计划类似地研究迁徙蝙蝠在生理和行为的其他方面的变异。拟议的分析发展将提高蝙蝠跟踪能力，并将对其他研究人员有用。提高对蝙蝠运动的了解对于蝙蝠野生动物管理决策和物种恢复工作是必要的。*

Many animals migrate, completing movements that range from relatively short trips to awe-inspiring continental-scale journeys. Variation in migratory movements is common within species and is often linked to variation in other traits. For example, longer-distance migrants may have body shapes that allow them to travel more efficiently than shorter-distance migrants of the same species. Studying variation among animals that migrate different distances can help us to better understand the factors that have contributed to the evolution of migration.**** Many bat species migrate, but migration in bats has not been studied nearly as much as in other groups. Because bats are nocturnal and difficult to observe, tracking them across space and time is challenging. Thus, we know surprisingly little about their basic movements. This is a problem because many North American bats are at risk and understanding their movements is important for their conservation. Previous research, including my own work, has shown that within-species variation in migratory movements is common in bats, but the factors driving this variation are largely unknown. Investigating this knowledge gap is a long-term research goal of mine.**** My research program has three immediate objectives. First (1), my students and I will study the links between variation in migratory movements, morphology, and life history categories (e.g. age, sex) in bats. To do this, we need to (2) continue describing basic bat migratory movements and (3) improve the techniques that we use to learn about bat migration.**** Previously, I have used chemical (stable hydrogen isotope) analyses of fur samples to study bat migration. We will continue to use and improve this technique and will also develop a less common method – strontium isotope analysis – for use on bats. Finally, we will use the Motus Wildlife Tracking System, an initiative that allows researchers to track migratory animals as they move. These three approaches will allow us to track migrants across a range of scales and with varying resolutions. We will be able to link the migratory movements of bats with other physical characteristics in ways that were not previously possible. My research team will work at locations across North America (including locally in Newfoundland), and with both live bats and museum specimens.**** Because bats are very distinct from other small flying migrants (e.g. birds, insects) this work will add a new dimension to our understanding of migratory theory. My proposal to study links between migratory and morphological variation is the first step in a longer-term plan to similarly examine variation in other aspects of physiology and behavior among migrant bats. The proposed analytical developments will improve bat tracking abilities and will be useful for other researchers. Improved understanding of bat movements is necessary for bat wildlife management decisions and species recovery efforts.***