Anatomical and functional differences in the vocal tract of domestic fowl(Gallus gallus) and the greater sage-grouse (Centrocercus urophasianus)
| . | Domestic fowl . | Sage-grouse (male) . | Sage-grouse (female) . |
|---|---|---|---|
| Tracheal tympanum (fused rings near base of trachea) | Present | Absent | Absent |
| Caudal tracheal cartilages | Laterally compressed region of 4–5 cartilages | Six pliable rings, similar in size and shape to rest of basal trachea | Cartilages similar in size, shape and ossification to rest of basal trachea |
| Site of sound production | Base of trachea (unpaired) | Bronchial–syringeal junction (paired) | Bronchial–syringeal junction (paired) |
| Intrinsic syringeal musculature | Absent | Very robust | Absent or virtually absent |
| . | Domestic fowl . | Sage-grouse (male) . | Sage-grouse (female) . |
|---|---|---|---|
| Tracheal tympanum (fused rings near base of trachea) | Present | Absent | Absent |
| Caudal tracheal cartilages | Laterally compressed region of 4–5 cartilages | Six pliable rings, similar in size and shape to rest of basal trachea | Cartilages similar in size, shape and ossification to rest of basal trachea |
| Site of sound production | Base of trachea (unpaired) | Bronchial–syringeal junction (paired) | Bronchial–syringeal junction (paired) |
| Intrinsic syringeal musculature | Absent | Very robust | Absent or virtually absent |
See Figs 1 and 7 for photographs