2023 136 ENV

Evaluation of Evaporative Water Loss in Anna's Hummingbirds

By: Christian Guerzon, Cecilia Doan, Rachael Tang

Department: Biology

Faculty Advisor: Dr. Derrick Groom

Hummingbirds like other avian species rely on various thermoregulatory mechanisms to maintain body temperature such as evaporative water loss (EWL). However, with climate change their thermoregulatory processes could be overwhelmed leading to a decline in population numbers. The problem however is that the mechanisms are not well defined in Hummingbirds compared to other avian species such as chickens or pigeons. My goal is to fill in this gap in knowledge. My research question is: what is the importance of EWL for hummingbird thermoregulation, and how does food availability affect EWL in hummingbirds? To test this, we captured wild hummingbirds and measured EWL under different temperature regimes. What we expected to find is that hummingbirds will demonstrate increased EWL in response to increased temperatures, and when given access to a meal. The results of this experiment are important to the field since it provides a baseline for hummingbird physiology and help us uncover the mechanisms of temperature regulation in some of the smallest endotherms. Understanding how access to resources affects this process as well can be a steppingstone for future experiments to understanding hummingbird thermoregulatory physiology, and small endotherms more broadly.