2020/07/06 by Amanda Monte, Alexander F. Cerwenka, Bernhard Ruthensteiner +2 · 1 citation
Biochemistry, Genetics and Molecular Biology · Agricultural and Biological Sciences · Environmental Science · Neuroscience · #Animal Vocal Communication and Behavior #Animal Behavior and Reproduction #Avian ecology and behavior #Syrinx (medicine) #Anatomy #Biology #Jacobin #Hummingbird #Neuroscience #Spinal cord
paper · pdf · doi:10.1186/s40850-020-00057-3
openalex publication_date 2020/07/06 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/29
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.