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Resonating feathers produce courtship song
Kimberly S Bostwick1, Damian O Elias, Andrew Mason
1Cornell University Museum of Vertebrates, 159 Sapsucker Woods Road, Ithaca, NY 14850, USA. ksb6@cornell.edu
Proceedings. Biological Sciences
|November 13, 2009
Summary
Male Club-winged Manakins produce unique sounds using specialized wing feathers. These feathers resonate at specific frequencies, supporting the resonant stridulation hypothesis for sound production in this bird species.
Area of Science:
- Ornithology
- Bioacoustics
- Biomechanics
Background:
- Male Club-winged Manakins (Machaeropterus deliciosus) produce a sustained tonal sound around 1500 Hz.
- This sound is hypothesized to originate from resonance within specialized wing feathers.
Purpose of the Study:
- To investigate the resonant properties of Club-winged Manakin wing feathers.
- To test the resonant stridulation hypothesis of sound production.
Main Methods:
- Laser Doppler vibrometry was used to measure the resonant frequencies and Q-values of wing feathers.
- Feathers from male Club-winged Manakins and two control species were analyzed.
- Measurements were taken on isolated feathers and feathers attached as a unit.
Main Results:
- Specialized Club-winged Manakin feathers showed a resonance peak near 1500 Hz with high Q-values (up to 27).
- Attached, unmodified feathers resonated as a unit, producing a strong second harmonic.
- Control species feathers had weaker resonance, lacked unit resonance, and produced no harmonics.
Conclusions:
- The findings strongly support the resonant stridulation hypothesis for sound production in Machaeropterus deliciosus.
- Specialized feather structures and their arrangement are crucial for generating the unique song.
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