Hummingbird feather sounds are produced by aeroelastic flutter, not vortex-induced vibration.

Aeroelastic flutter produces hummingbird feather songs.

During courtship flights, males of some hummingbird species produce diverse sounds with tail feathers of varying shapes. We show that these sounds are produced by air flowing past a feather, causing it to aeroelastically flutter and generate flutter-induced sound. Scanning laser doppler vibrometery and high-speed video of individual feathers of different sizes and shapes in a wind tunnel reveal...

Structural resonance and mode of flutter of hummingbird tail feathers.

Feathers can produce sound by fluttering in airflow. This flutter is hypothesized to be aeroelastic, arising from the coupling of aerodynamic forces to one or more of the feather's intrinsic structural resonance frequencies. We investigated how mode of flutter varied among a sample of hummingbird tail feathers tested in a wind tunnel. Feather vibration was measured directly at ~100 points acros...

Supporting Online Material for Aeroelastic Flutter Produces Hummingbird Feather Songs

Evaluation of 2-D Aeroelastic Models Based on Indicial Aerodynamic Theory and Vortex Lattice Method in Flutter and Gust Response Determination

Two 2-D aeroelastic models are presented here to determine instability boundary (flutter speed) and gust response of a typical section airfoil with degrees of freedom in pitch and plunge directions. To build these 2-D aeroelastic models, two different aerodynamic theories including Indicial Aerodynamic Theory and Vortex Lattice Method (VLM) have been employed. Also, a 3-D aeroelastic framework ...

The Displays and Sonations of the Black-chinned Hummingbird (trochilidae:

—Studies on the sonations (nonvocal communicative sounds) of birds have revealed a wide diversity of mechanisms and functions. We describe the kinematics and sounds of the display dive and shuttle display of the male Black-chinned Hummingbird (Archilochus alexandri). Males produced an integrated series of trilled and tonal sounds during their displays. Through a combination of experiments on wi...