Apr 16 2010
For several weeks we’ve learned about body parts that are the same on birds and humans. Today’s lesson is very different.
The cloaca is a bird anatomy part most people never see. It’s under the bird and usually covered by feathers.
Cloaca (pronounced klo-A-ca) is a Latin word that means “to cleanse” and is aptly used to name the bird’s single opening for its urinary, intestinal and reproductive tracts. Here it is on a great egret, circled in pink.
This multi-purpose “vent” may seem odd but male mammals have a single opening for urine and semen. Birds economize further. Everything happens at one location for them.
When birds mate, they touch their cloacas for a few seconds. This brief “cloacal kiss” is just enough time to transfer semen to the female.
If you don’t like the sound of “cloaca” you can use the word “vent,” a prettier, alternative name.
(photo of the underside of a great egret, including cloaca, by Chuck Tague)