The hummingbird syrinx morphome: a detailed three-dimensional description of the black jacobin’s vocal organ
Abstract
Background
The ability to imitate sounds depends on a process called vocal production learning, a rare evolutionary trait. In addition to the few mammalian groups that possess this ability, vocal production learning has evolved independently in three avian clades: songbirds, parrots, and hummingbirds. Although the anatomy and mechanisms of sound production in songbirds are well understood, little is known about the hummingbird’s vocal anatomy.
Results
We use high-resolution micro-computed tomography (μCT) and microdissection to reveal the three-dimensional structure of the syrinx, the vocal organ of the black jacobin (Florisuga fusca), a phylogenetically basal hummingbird species. We identify three features of the black jacobin’s syrinx: (i) a shift in the position of the syrinx to the outside of the thoracic cavity and the related loss of the sterno-tracheal muscle, (ii) complex intrinsic musculature, oriented dorso-ventrally, and (iii) ossicles embedded in the medial vibratory membranes.
Conclusions
The extra-thoracic placement of the black jacobin’s syrinx and the dorso-ventrally oriented musculature likely aid to uncoupling syrinx movements from extensive flight-related thorax constraints. The syrinx morphology further allows for vibratory decoupling, precise control of complex acoustic parameters, and a large motor redundancy that may be key biomechanical factors leading to acoustic complexity and thus facilitating the occurrence of vocal production learning. Show more
Permanent link
https://doi.org/10.3929/ethz-b-000429165Publication status
publishedExternal links
Journal / series
BMC ZoologyVolume
Pages / Article No.
Publisher
BioMed CentralSubject
Vocal production; Musculus sternotrachealis (ST); Intrinsic musculature; Vibrato; EvolutionOrganisational unit
03774 - Hahnloser, Richard H.R. / Hahnloser, Richard H.R.
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