Table 1 Size measurements of two male and two female vocal tracts
From: Vocal tract anatomy of king penguins: morphological traits of two-voiced sound production
| Sex | Trachea length (mm) | Diameter Trachea caudal end (mm) | Diameter mid Trachea (mm) | Diameter Trachea cranial end (mm) | Right ML length (mm) | Left ML length (mm) | ∆ ML (mm) |
|---|---|---|---|---|---|---|---|
| Male 1 | 270 | 17.6 | 21.9 | 23.0 | 19.3 | 19.1 | 0.2 |
| Male 2 | 270 | 18.9 | 21.6 | 21.0 | 20.6 | 20.5 | 0.1 |
| Male 3 | NA | NA | NA | NA | 18.1 | 18.5 | - 0.4 |
| Male 4 | NA | NA | NA | NA | 18.0 | 17.1 | 0.9 |
| Female 1 | 295 | 18.6 | 20.0 | 21.1 | 19.7 | 19.5 | 0.2 |
| Female 2 | 275 | 18.2 | 19.6 | 20.5 | 18.4 | 19.0 | - 0.6 |