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

9903715温克勒鸟的捕食者被认为通过以不成比例的高比率杀死稀有的变种来限制在赫利柯斯杂交区的扩散，然而导致这种频率依赖选择的捕食行为的机制尚不清楚。特别是，需要对像杰克鱼这样的特殊捕食者进行实验研究。本论文的研究将致力于三个相关的目标：(1)量化海象的学习和遗忘率，(2)设计和测试测量海象和海象密度的快速评估调查，以及(3)比较海象杂交区狭窄和宽广区域的依附率和捕食者-猎物密度。对于目标1和目标2，将在委内瑞拉采用笼式和实地试验相结合的方式。对于目标3，将在玻利维亚一个可变的杂交区研究两个样带，一个宽一个窄，沿着每个样带设置七个试验田，比较雅卡玛和赫利科乌斯的攻击率和密度。通过测试模仿模型的一个重要组成部分，通过扩大我们对专业捕食者如何学习和忘记模仿猎物的知识，通过探索一个独特的新热带鸟类的觅食行为，对Helconius杂交区的Jacamar捕食行为的调查将丰富所有的模仿研究。

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.