Quail (Coturnix coturnix) Science Article 1
While handling the Eurasian quail, Coturnix coturnix, in a game stocking program, the junior author noted that the breeding males issued a frothy fluid from their cloac . Upon examination we noted that this secretion originated in a gland located above the dorsal lip of the cloaca. There is a hypertrophy of this glandular tissue which is associated with enlarged testes (15 x 25 mm in size) and with great behavioral sexual activity of the male. There seems to be little doubt that this secretion is associated with the mechanics of internal fertilization. There exudes a copious, clear secretion from many small pores over the surface of the gland. The secretion becomes full of air bubbles and fills the cloaca with a meringuelike froth. It is also evacuated on defecation and clings to the droppings; the latter occurrence causes caged birds to accumulate large balls of dung on their toes. The froth is transferred to the cloaca of the female during copulation.
William H. Coil AND David K. Wetherbee, THE OHIO JOURNAL OF SCIENCE 59(5): 268, September, 1959.