Courtship vocalizations in male ducks: spectral composition and resonance of the syringeal bulla.

ABSTRACT: Ducks display a unique and dramatic sexual dimorphism in their vocal organ, the syrinx. Males have a left-sided bulla that is not present in females and that has been long hypothesized to play a role in courtship vocalizations, though this connection has never been tested. The large, hollow morphology of the bulla and its proximity to the sound-producing vocal folds introduce the possibility that it may work as a Helmholtz resonator, which makes it possible to predict the resonance frequencies enhanced by this structure. We found that during early ontogeny, the distribution of energy across the harmonic spectrum of contact calls is not different between males and females. We then used microcomputed tomography (µCT) scans of duck syringes to estimate resonance frequencies of the bullae and

SUBMITTER: Mishkind D 

PROVIDER: S-EPMC12633744 | biostudies-literature | 2025 Nov

REPOSITORIES: biostudies-literature