We recently received a great question from a blog reader about our post on chicken intelligence, and I was SO excited about the question that I had to investigate. It seems that our reader, Leslie, has a rooster who adores her, and likes to sit on her lap for long periods of time. What’s interesting is, he never poops on her during these long snuggles and Leslie is curious to know if it's possible that the rooster is somehow controlling himself while on her lap. Birds are often described as not having sphincters, so our rooster-whisperer was wondering, if this is really true, what explains her clean lap after cuddles?
This is such an interesting question, and not an easy one to answer. Although birds don’t have the same kind of muscled sphincter that we do, which is meant to control when we choose to go, they do still have some muscles around their cloaca, which is their everything hole—eggs and excrement all come from the same place! I couldn't find a lot of peer-reviewed science on the subject (where are all the bird-buttologists?), however I did find one paper on duck- derrière-science from the 80’s. In it, the authors speculate that birds have something called a rectocoprodeal sphincter, which helps control the flow of feces, at least a little bit. That said, birds still don’t have the same level of control as we do.
A few other things to consider about Leslie's rooster:
Bird size will determine how often they poop. Small birds may poop every 10 minutes or so, and large birds, like chickens, would do it less frequently. The advantage of not having a well-controlled sphincter for a bird means that you don’t have to decide to poop while in flight, which keeps you light—a big advantage for flight efficiency.
Still, birds can feel when they need to poop. This is evident while observing chickens in the act, since they alter their position while pooping. It doesn’t just come out, unbeknownst to them! If you have the opportunity to observe a chicken, you’ll notice they lean forward a little to help with the process.
Leslie’s rooster friend likely knows if a poop is coming and hops off her lap in time, out of respect for his pal.
The urge to poop seems to be triggered by pressure built up by the presence of feces inside, which, I speculate, might not be as high when they are sitting in a certain position. If you think about it, they do not poop for long periods of time while incubating an egg, or roosting at night. The fact that they are not eating around that time certainly also plays a part in why they aren’t pooping then. However, brooding chickens go on to have HUGE poops after they finally get up from sitting on the nest for a long time, so feces are definitely building up and held inside for longer than is typical during those periods.
In the end, I can't say for sure. There could be many factors at play, but no matter what’s going on, Leslie is pretty lucky. Our chickens at Science World poop on us when we handle them sometimes, so I guess they don’t respect us the same way that rooster revered her. If any readers have any further leads on the fascinating science of birds pooping, please leave a comment! Based on the lack of published papers on the subject, I see a master’s project in someone’s future. I’m sure that person would be a hit at parties when asked, "So, what do you study?"