Intercourse happens when these two openings are brought together in what ornithologists refer to as a cloacal kiss. 性交的过程就是两个生殖器开口凑到一起,鸟类学家称之为泄殖腔交配。
Most Birds mate by joining their cloacas in a" cloacal kiss"; muscular contractions transfer the sperm from the male to the female. 但多数鸟类仅以泄殖腔互相接触,藉肌肉收缩而把雄鸟的精子送给雌鸟。有胎盘哺乳动物及多数硬骨鱼无泄殖腔。
Cloacal \Clo*a"cal\, a. Of or pertaining to a cloaca.