The hummingbird syrinx morphome: a detailed three-dimensional description of the black jacobin’s vocal organ

Autor: Amanda Monte, Alexander F. Cerwenka, Bernhard Ruthensteiner, Manfred Gahr, Daniel N. Düring
Jazyk: angličtina
Rok vydání: 2020
Předmět:
Zdroj: BMC Zoology, Vol 5, Iss 1, Pp 1-15 (2020)
Druh dokumentu: article
ISSN: 2056-3132
DOI: 10.1186/s40850-020-00057-3
Popis: 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.
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