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

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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.