The Syrinx of the Male Mallard (Anas platyrhynchos): Special Anatomical Features

Abstract

The aim of this study was to investigate the special anatomical and topographical features of the syrinx in male adult stock ducks (Anas platyrhynchos). The syrinx of the mallard is a tracheobronchial type, consisting of a tympanum, a pessulus, medial tympaniform membranes, interanular membranes, an interbronchial ligament (bronchidesmus), and bronchosyringeal cartilage semi-rings. Using a frozen sagittal section, it was possible to document the syringeal valve at the right lateral side of the tympanum. In the male stock duck the pessulus was massive and showed a longish oval, transparent area ventrally. The middle part of the pessulus had a nose-shaped process on its left side, on which the left medial tympaniform membrane originated. The left-sided, pear-shaped syringeal bulla was divided into a left major and right minor chamber by a double-walled, semilunar and opaque septum, approximately 5-6 mm in height. The first left and right C-shaped bronchosyringeal cartilage was more prominent than the other ones and showed partial ossification. In addition, the first left bronchosyringeal cartilage was obviously thicker than the right one. In conclusion, it can be stated that the syrinx in male adult mallards shows some notable specific anatomical features that might have an influence on vocalization. However, to understand the complex mechanism of vocalization in mallards, more investigations, especially obtained by sonography and endoscopy, will be needed.

Functional Anatomy of the Syrinx of the Chukar Partridge (Galliformes: Alectoris chukar) as a Model for Phonation Research

“…Similar to the anatomy of the syrinx, the number and type of the cartilages contributing to the formation of the tympanum vary among birds as well. The tympanum is formed by fusion of the last five to seven tracheal rings in chickens (Gross, ), by the fusion of the last two tracheal rings in quail (Bayram and Liman, ), by the union of the last ten tracheal rings in the mallard (Frank et al, ) and by the fusion of the last four to six tracheal rings in the murre (Miller et al, ). In the current study, we observed that the tympanum was formed by the fusion of the last two tracheosyringeal rings.…”

“…The tympanum, tracheal and bronchial cartilages are ossified in the common murre (Miller et al, ). Moderate ossification was reported in the ventral part of the bronchio‐syringeal semi‐rings in mallards (Warner, ; Frank et al, ). In contrast to this, all bronchial rings in the partridges were composed of cartilaginous tissue.…”

Kazda (Anser anser domesticus) Larynx, Trachae and Syrinx’in Makroskobik Anatomisi

“…It has been reported that the shape of the pessulus differs among birds. While it was the dagger shaped in domestic fowls 2,3,31 half prism shaped in Japanese quail 29 and lengthwise oval shaped in male duck 19 , it was columnar in the present study.…”

“…The role of these structures in vocalization 32 and neuro musculer control of voice and function of syringeal muscles 22 have been investigated. Sexual dimorphism was observed in mallards and the differences for it were investigated in detail 19 .…”

Anatomical features of the syrinx in sea gulls

“…Bottom of the trachea or mostly top of bronchus or both of them participates in the formation of syrinx. It has 3 types according to origination and called tracheal, bronchial and tracheobronchial syrinx (1,4,5,10,11,13,14). Tracheobronchial syrinx is consist of tympanum, cartilagines tracheosyringeales and cartilagines bronchosyringeales (1,10,11,14,15,16,17).…”