University Honors

This study investigates the effects of smoke exposure on the behavior and lung health of wild-caught Anna’s hummingbirds. Twelve birds were placed in individual insect cages with a syringe of 30 mL of nectar solution. Half the birds, the smoke group, were placed inside an environmental chamber and exposed to cold wood smoke of 1,419 µg/m3 concentration for 4 hours. The remaining six birds, the control group, were placed in a separate environmental chamber without smoke. At the end of the exposure, half of each group was euthanized immediately to study short-term effects on the lungs, including acute inflammation, immune cell infiltration, and carbon deposition. The other half were euthanized two weeks later to study long-term effects on the lungs, such as fibrosis and structural damage. A necropsy was performed on all the birds. Their lungs were processed for immunohistochemistry and analyzed after Hematoxylin and Eosin (H&E) staining. Observational results showed no differences in behavior between the two groups during the experiment. Statistical results (T-tests) showed no difference in food consumed by the smoke group versus the control group, but did show that the males ate more than the females. Additionally, neither group had significant data on weight loss nor gain after the experiment. Overall, this research aims to advance our understanding of avian respiratory physiology and behavior and enhance our understanding of the size and density of particulates that affect hummingbird lungs after wildfires.