Dissertation Research: Role of Predation by Jacamars (Aves: Galbulidae) in Maintaining Hybrid Zones of Heliconius Butterflies

9903715温克勒鸟类捕食者被认为是通过以不成比例的高比率杀死稀有变种来限制Heliconius杂交区的扩散，但导致这种频率依赖性选择的捕食行为机制尚不清楚。特别是，需要对像jacamars这样的专门捕食者进行实验研究。本论文的研究将解决三个相关的目标：（1）量化的学习和遗忘率在jacamars，（2）设计和测试快速评估调查测量密度的jacamars和Heliconius，（3）比较附着率和捕食者-猎物密度在一个狭窄的和广泛的区域的Heliconius混合区。对于目标1和2，将在委内瑞拉采用笼中试验和实地试验相结合的方法。对于目标3，将在玻利维亚的一个可变杂交区研究两个样带，一个宽的和一个窄的，沿着每个样带设置七个实验区，比较美洲黑腹蛛和Heliconius的攻击率和密度。在Heliconius混合区的jacacalopsis捕食的调查将丰富所有的模仿研究，通过测试模仿模型的一个关键组成部分，通过扩大我们的知识，专门的捕食者如何学习和忘记模仿猎物，并通过探索觅食行为的一个不同的家庭的新热带鸟类。

9903715WinklerAvian predators are thought to constrain dispersal across Heliconius hybrid zones by killing rare morphs at disproportionately high rates, yet the mechanisms of predatory behavior leading to this frequency-dependent selection are unknown. In particular, experimental investigations of specialized predators like jacamars are needed. This dissertation research will address three related objectives: (1) to quantify learning and forgetting rates in jacamars, (2) to design and test rapid assessment surveys measuring the density of jacamars and Heliconius, and (3) to compare attach rates and predator-prey densities in a narrow and wide region of a Heliconius hybrid zone. For objectives 1 and 2, a combination of cage and field experiments will be employed in Venezuela. For objective 3, two transects, one wide and one narrow, will be studies in a variable hybrid zone in Bolivia by setting up seven experimental plots along each transect and comparing attack rates and densities of jacamars and Heliconius. An investigation of jacamar predation in Heliconius hybrid zones will enrich all mimicry studies by testing a crucial component of mimicry models, by expanding our knowledge of how specialized predators learn and forget mimetic prey, and by exploring the foraging behavior of a distinct family of neotropical birds.