Investigating Hummingbird Foraging Choices in Response to Bee or Ant Cues

Undergraduate #53
Discipline: Ecology Environmental and Earth Sciences
Subcategory: Ecology

Ashley Kim - University of California Davis
Co-Author(s): Dr. Erin Wilson Rankin, University of California Riverside, Riverside, CA

Hummingbirds are known to utilize visual cues while foraging for nectar. When some arthropods are present on flowers, hummingbirds have been observed to avoid those occupied flowers. To better understand their responses, hummingbirds participated in a series of choice-experiments to identify what cues the birds responded to and how. Three species of hummingbirds: Anna’s (Calypte anna), Costa’s (Calypte costae), and Anna’s x Costa’s hybrids were used in the study in both captivity and the field. In addition to studying visual cues, olfactory cues were also tested in the study to further investigate behavioral mechanisms. The visual and olfactory treatments were extracted from native wood ants (Formica francoeuri), invasive Argentine ants (Linepithema humile) and European honeybees (Apis mellifera). The three treatments include formic acid (wood ant defense cue), Z9 pheromones (Argentine ant aggregation cue), and cuticular hydrocarbons (associated with honeybee foraging). Although not known for their sense of smell, hummingbirds in this study exhibited some ability to distinguish insect chemical cues in different ecological contexts. Such data describing how avian pollinators respond to insect-derived chemical signals at floral resources will improve our understanding of plant-pollinator and inter-pollinator interactions.

Funder Acknowledgement(s): National Science Foundation (NSF), Bill & Melinda Gates Foundation Grand Challenge Award, Vodafone's Wireless Innovation Project, and a UCR Chancellors Award.

Faculty Advisor: Dr. Erin Wilson Rankin, erin.rankin@ucr.edu

Role: My mentor first presented me the idea of working with hummingbirds and insects to study their ecological interaction on olfactory and visual cues. I studied related primary literatures and created my own experimental design. In addition, I completed about 80% of the experimental trials out in the field. Then I inputted the data and analyzed it with my mentor using the programming language 'R'. We are currently writing our findings in a scientific paper and I will be listed as the primary author. I would like to acknowledge and thank my mentor for providing guidance every step of the way.