Dissertation Research: Biomechanics of Feeding in Loggerhead Shrikes

众所周知，幼鸟比成年鸟更不容易捕捉到食物，这可能是它们在出生后的第一年内经常死亡的部分原因。 然而，目前尚不清楚这种喂养差异是否是由于所有幼鸟通过学习来提高它们的喂养能力，或者成年鸟是否是更好的饲养者，因为所有身体或行为缺陷的幼鸟在早期阶段都会死亡，只有那些表现更好的才能达到成年。 本研究的目的是区分这些可能性之间的联邦濒危圣克莱门特Loggerhead伯劳（Lanius ludovicianus mearnsi），一种捕食鸣禽特有的圣克莱门特岛，加州。 随着时间的推移，他们的猎物捕获，处理和喂养性能的变化将使用高速视频成像测量。 饲养性能直接关系到其他鸟类的生存和繁殖成功。 这项研究将提供管理人员养殖伯劳在圈养，以重新建立野生种群的客观标准，决定个别伯劳有可能养活自己成功地如果释放，并在哪个发展阶段。 这项研究也将推进我们的理论理解，为什么喂养性能随着年龄的增长而提高，哪些身体和行为特征对成功捕获猎物很重要，以及伯劳作为一个群体如何进化出显着的捕食能力。 最后，由于用于测量摄食性能的分析技术具有独特的生物医学应用（例如，运动生理学、运动生理学、物理治疗），该项目还将培养寻求医疗、健康和野生动物专业职业的本科生。

It is well known that young birds succeed less often at catching food than do adults; this may be part of the reason that they frequently die during their first year of life. However, it is not clear whether this difference in feeding results from all young birds individually improving their feeding performance by learning over time, or whether adult birds are better feeders because all the physically or behaviorally deficient young birds die out at earlier stages, leaving only those that perform better to reach adulthood. The aim of this study is to distinguish among these possibilities in the federally endangered San Clemente Loggerhead Shrike (Lanius ludovicianus mearnsi), a predatory songbird endemic to San Clemente Island, California. The change over time of their prey capture, processing, and feeding performance will be measured using high-speed video imaging. Feeding performance has been directly linked to survival and reproductive success in other birds. This study will provide managers breeding shrikes in captivity in order to re-establish wild populations with objective criteria for deciding which individual shrikes are likely to feed themselves successfully if released, and at which stage of development. This study will also advance our theoretical understanding of why feeding performance improves with age, which physical and behavioral characteristics are important for successful prey capture, and how shrikes, as a group, have evolved their remarkable predatory capabilities. Finally, because the analytical techniques used for measuring feeding performance have distinct biomedical applications (e.g., kinesiology, exercise physiology, physical therapy), this project will also train undergraduate students who seek careers in medical, health, and wildlife professions.