Meeting Abstract
Hummingbirds use energy at extremely high rates due to their high metabolism. Their small size forces them to conserve energy robustly, often going into torpor at night during times of high energetic stress (i.e. when food is scarce, or when they are injured), dramatically reducing their metabolic rate and body temperature. It is unclear what strategies incubating females use to conserve energy while still maintaining sufficient temperatures for healthy development of offspring. We aim to quantify the energetics associated with nesting female hummingbirds using thermal imaging. We predict that in order to incubate their eggs effectively, nesting hummingbirds would be unable to enter torpor. Rather than using deep torpor, hummingbirds may use a shallow metabolic reduction, or shallow hypothermia. Additionally, the degree to which metabolism is decreased is predicted to be dependent on ambient conditions (e.g. temperature, wind, precipitation). This project located 26 active Allen’s hummingbird (Selasphorus sasin) nests on the Loyola Marymount University campus in Los Angeles, California between January and May, 2017. Nightly time-lapse thermal images were recorded at 12 of these nests using the FLIR Vue Pro R thermal camera. Analysis of these data and validation of this methodology are on-going. Following this initial investigation, we hope to apply a similar methodology to different species in colder environments, such as the ruby-throated hummingbird (Archilochus colubris) in Toronto, Ontario. This project has important implications for understanding the physiology of how animals cope with extreme, and sometimes conflicting, energetic requirements. It also presents broad applications for citizen science and science education.
