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

[9903715] winkler鸟类捕食者被认为以不成比例的高速率杀死稀有变种，从而限制了Heliconius杂交区域的扩散，然而导致这种频率依赖选择的捕食行为机制尚不清楚。特别是需要对像豺这样的特殊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)量化狐獴的学习和遗忘率；(2)设计和测试测量狐獴和Heliconius密度的快速评估调查；(3)比较Heliconius杂交区窄区和宽区内的附着率和捕食者-猎物密度。为了实现目标1和2，将在委内瑞拉采用笼子和实地试验相结合的方法。为了实现目标3，将在玻利维亚的一个可变杂交区研究两个横断面，一个宽一个窄，方法是沿着每个横断面设置7个试验田，并比较jacamars和Heliconius的攻击率和密度。通过测试模仿模型的一个关键组成部分，通过扩展我们对特殊捕食者如何学习和忘记模仿猎物的知识，以及通过探索一种独特的新热带鸟类家族的觅食行为，对Heliconius杂交区jacamar捕食行为的调查将丰富所有模仿研究。

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.