Meeting Abstract
Wild birds exhibit countless flight behaviors previously unstudied in biomechanical laboratories because the behaviors are limited to field or natural settings. For example, conspecific aggressive interactions are common in competition for food, mates, and habitat in many species. During such behaviors, birds may exhibit flight performance parameters near physiological limits previously unexplored in lab settings. Wild American Goldfinches (Carduelis Tristis) were recorded arriving and departing within 1 m of a bird feeder using high speed videography techniques to triangulate flight paths and calculate flight kinematics. Over nine days of recording, with an estimated seven individual birds, we recorded 30 arrivals, and 50 departures, which were subcategorized based on whether the target bird was forced by a conspecific to take off or left voluntarily. Most flight paths involved velocities between 0 and 2 ms-1, indicating potentially costly low-speed flight. Approaching birds frequently scrubbed kinetic energy by gaining potential energy as they swooped from beneath the feeder. Voluntarily departing birds reversed the approach strategy, and dove from the feeder to trade kinetic for potential energy. Birds forced from the feeder by a competitor usually accelerated horizontally under power, and gained greater horizontal velocities (4.5 ms-1) in a shorter time (0.25 s) than freely departing birds. However, many observed interactions involved maneuvering at near-hovering velocities, suggesting that high flight speed and acceleration are not the only parameters involved in competition in flight. Supported by LU-PRISM.
