DISSERTATION RESEARCH: Sex-biased dispersal: mechanisms and consequences in changing environments

生态学家面临的最大挑战之一是准确预测自然世界将如何随着时间的推移而变化。随着人类不断改变景观，了解生物如何应对这些变化以及自然世界的恢复能力是很重要的。这一领域的科学研究有一个实际的目的，即衡量增长和扩张的潜在成本，同时促进对自然世界的基本理解。该项目将开发一种新的方法来研究生物如何应对变化，这将为面临广泛环境变化的多种生物提供更大的细微差别和预测能力。扩散是影响生物生态和进化的重要过程，但个体扩散能力变化的后果尚不清楚。一种特别常见的种内分散形式发生在物种的雄性和雌性之间，本项目将研究性别偏向的分散如何影响变化环境中元种群的持久性。作者之前的研究发现，成年雌性和幼虫蜻蜓，通常被称为蜻蜓和豆娘，受到环境的高度限制，而成年雄性经常分散到不合适的栖息地。这表明在散布距离和栖息地选择上都存在偏差。为了研究这种不同扩散行为背后的具体行为机制，将进行互惠移植实验。在人工介孔中饲养成年齿鼠，捕获并标记，然后将其释放到不适合栖息地的介孔中。有标记的个体在靠近放生地点的地方定居，无论该栖息地的环境质量如何，都表明蜻蜓在它们的分散行为中没有选择，而是在靠近家的地方定居。这种行为在不断变化的环境中有着重要的影响。通过将模式、机制和普遍性联系起来，这个项目将提供更多的证据，证明有性别偏见的扩散和更普遍的个体变异的生态重要性。该项目将通过提供实地实验测试新开发模型的机会，大大促进博士生的培训。调查人员将通过现有的项目向公众展示结果，如星空下的科学、特拉维斯奥杜邦协会、首都地区自然学家大师和奥斯汀蝴蝶论坛——致力于提高公众对自然社区的认识的当地组织。

One of the biggest challenges that ecologists face is making accurate predictions about how the natural world will change over time. As humans continue to alter landscapes, it is important to understand how organisms will respond to these changes and how resilient the natural world will be. Scientific research in this area serves a practical purpose, for gauging the potential costs of growth and expansion, while it advances fundamental understanding of the natural world. This project will develop a novel approach to examine how organisms respond to change that will provide greater nuance and predictive power for a diverse organisms facing wide-ranging environmental change. Dispersal is an important process that affects the ecology and evolution of organisms but the consequences of individual variation in dispersal ability are not well understood. One particularly common form of intraspecific variation in dispersal occurs between males and females of a species, and this project will investigate how sex-biased dispersal affects the persistence of metapopulations in changing environments. Previous studies by the authors have found that adult female and larval odonates, commonly known as dragonflies and damselflies, are highly constrained by their environment, while adult males often dispersed into unsuitable habitat. This suggests that biases exist for both dispersal distance and for habitat choosiness. In order to investigate the specific behavioral mechanisms behind this differing dispersal behavior, a reciprocal transplant experiment will be performed. Emerging adult odonates will be raised in artificial mesocosms, captured and marked, then released at mesocosms containing unsuitable habitat. Settlement of marked individuals close to the release location, regardless of the environmental qualities of that habitat, will suggest that dragonflies are not choosy in their dispersal behavior, but rather settle close to home. This behavior has important consequences in changing environments. By linking pattern, mechanism, and generality, this project will be providing more evidence of the ecological importance of gender-biased dispersal and of individual variation more generally. The project will significantly advance training of a doctoral student by providing the opportunity to test newly-developed models with field experiments. The investigators will present results to the public through existing programs such as Science Under the Stars, Travis Audubon Society, Capital Area Master Naturalists, and the Austin Butterfly Forum - local organizations committed to raising public awareness of natural communities.