Meeting Abstract

25.2  Monday, Jan. 5  Resonant Feathers Enable Sound Production in Machaeropterus deliciosus (Aves) BOSTWICK, Kimberly/S*; ELIAS, Damian; MASON, Andrew; MONTEALEGRE-Z, Fernando; Cornell University; University of British Columbia; University of Toronto Scarborough; University of Bristol ksb6@cornell.edu

Male Club-winged manakins produce a unique, sustained, tonal sonation while perched during courtship. The sound is hypothesized to result from excitation of resonance in a modified secondary feather at or near the fundamental frequency of the sound produced in nature. Here we use laser vibrometery to measure and compare the resonant properties of the secondary feathers of the Club-winged manakin relative to other non-sonating manakin species to test the resonant part of the resonant stridulation hypothesis. While the control species show no resonant peaks above ~100 Hz, we determined that the enlarged 6th and 7th secondary feathers demonstrate a pronounced frequency peak near 1500 Hz, and further exhibit Q properties exceptionally high for a biological object. The other secondary feathers of the wing do not exhibit strong resonant frequency properties when measured by themselves. However, when measured in the context of the modified secondary feathers they are induced to resonant at the 1500Hz frequency. These results lend critical support to the resonant stridulation hypothesis of sound production in Machaeropterus deliciosus.