The cloaca (also called the vent) is the opening to a bird’s digestive, reproductive and urinary tracts. In other words, when your bird poops, that’s the cloaca at work. Whereas mammals have separate openings for each of these systems, birds, reptiles and amphibians only have one: the cloaca. That means that your bird also urinates through the cloaca.
In addition to serving as the point of evacuation for the digestive and urinary tracts, the cloaca is also the opening to the bird’s reproductive tract. For birds, reproduction is as simple as a cloacal kiss: two birds touch their cloacae together for a few seconds, and the reproductive material is transmitted. Then, in two or three days, the female bird might begin to lay eggs if fertilization was achieved. Female birds lay eggs through the cloaca.
The cloaca can also be an indicator of your bird’s health. If you notice your bird straining or there’s a lot of poop stuck to the cloaca and the feathers around it, this can indicate a health issue. In addition, pet birds can experience a cloacal prolapse, which means that the muscles in the bird’s digestive, reproductive or urinary tract loose strength to the point where internal organs are unable to be supported. The internal organs fall through the cloaca, leaving them exposed outside of the bird’s body. In the case of cloacal prolapse, surgery is often required to correct the problem. Speak to your avian veterinarian for more information.
Interesting Fact: the word “cloaca” can also refer to an ancient sewer. In fact, the word itself comes from the Latin word for “sewer” and the Greek word for “to cleanse.”