Re: Do chickens use the same orfice to defecate that they use to lay eggs?

Birds, reptiles, amphibians, fish, and monotremes (platypuses and echidnas) all 
have their urogenital and alimentary tracts joined internally to form the 
cloaca (Klow-ay-kuh).  The cloaca is a muscular sinus analogous to the 
rectum in higher mammals which allows the urine and fecal material to mix prior 
to excretion, which is why bird droppings contain both solid and liquid 
components.  Since the oviducts which carry the eggs join the urethra as it 
enters the cloaca, the eggs must pass through the cloaca as well, as they are 
being layed.  A cloaca forms during early human development, but is lost during 
later remodelling of the urogenital tract.