I have pet parrots. For the most part, they’ll actually swing their butts off your shoulder/arm/hand and poop.
When angry, however, they will fly up to you, stand on one or another body part, look you straight in the eye, and let the crap fly all over you. Then they fly off before you snatch their little birdy butts and throttle them for the insult.
So, in the case of my family flock the answer would appear to be yes.
ETA: Ah, zombie that I had already answered. Oh, well…
Huh. From grammar school biology, I remember my teacher saying that birds don’t have bladders. They poop as soon as it’s, um, produced. They don’t have bladders because they always want to reduce their flying weight as soon as it is possible to do so. My little mind conflated bladders and sphincters. So storing poop and having conscious control over it is a revelation to me.
J.
I seem to recall skuas do this to defend their nesting sites - or is that vomiting?
I recall my ornithology professor relating a story about a test he ran on mobbing behavior. He had a friend’s pet owl tethered to a stump in the daytime in an open field with no cover and watched as a flock of small birds responded to it. Apparently there was a ripe berry bush nearby and said birds had been feeding - they then proceeded the dive-bomb the owl while pooping copiously on it.
Apparently by the time they halted the little experiment the poor owl was absolutely soaked with partially digested berry juice ;).
I would say yes to the question.
Years ago I arrived home and parked my car in the street as usual. As I started walking under my backyard tree I looked up to see a bird sitting on a branch. he turned his tail on me so I stopped I walked in an arc to the opposite side of the branch and the bird proceeded to turn his tail in my direction. I repeated this 4 more times each time getting the same result. The bird would do an about face. So I boldly walked toward him and sure as shit he hiked one in my direction. I side stepped the messy affair but there is no doubt in my mind it was deliberate.
I never knew there was a word for that, which of course there would be if I had thought harder. Thanks.
I see it all the time from the pigeons against red hawks who nest around here.
Birdie, birdie in the sky,
Why’d you do that in my eye?
I’m a big boy and I don’t cry.
But I’m sure glad that cows don’t fly.
Broomstick: My family keeps and ‘rescues’ parrots (currently have a Monk and a Nanday, and had a 5yr-old Umbrella Cockatoo for two years before he found a stray battery somewhere and died from lack of availability of a compounding pharmacy anywhere in Central US that could make Calcium EDTA - find a source, fwiw, just in case! Vet had no idea of where it could be made). Our birds are flighted and when we get visitors, occasionally one of them will beeline to person who, for whatever reason, poops upon their back/neck as they fly overhead. We cage them when we know a ‘new’ person’ is coming over, and make introductions, etc, so poop is avoided (most of time).
An interesting tidbit - the Nanday will NOT poop in his smaller night-cage, and holds his poop at wake-up time until we set him upon a certain perch on door of large day-cage. Then he lets loose with a large amount as if he wants to avoid soiling where he spends most off his day within the rarely closed cage.
Parrots are amazingly smart, especially the bigger ones, and carry grudges against certain persons/personalities with a passion. Our U2 figured out how to ‘unlock’ the two standard cage ‘locks’ on large day-cage, so we had to use a small padlock whenever we went out of town or gone for awhile, just as an example. He worked on that lock with all his attention for days before he gave up trying to overcome it, LOL.
Do birds ever crap on people on purpose?
It sure seems like it. There’s a reason fisherman and golfers wear those goofy hats, although maybe that’s what attracts the birds.
There was some nature (I’m thinking Nature on PBS?) show I seen a good while back, where many birds were literally bombarding a predator with bird poop. Can’t remember what kind of birds, or what predator that was on the receiving end. But I assume if they felt threatened with humans, they could do the same.
Birds don’t have a bladder because the ureter from the kidneys empties into the cloaca, a structure that doesn’t really have a good equivalent in humans. However, the cloaca does have a terminal sphincter, meaning birds can control when they defecate.
My green check conure does the same thing. Doesn’t want to poop in his bedroom, I guess.
Broomstick: Now ya got me wondering if its a kinda ‘trait’ of conures overall! Interesting to say the least. Outside of night cage, the Nanday and Quaker (aka Monk parrot) poop wherever they are at the time more often than not. Lots of newspapaer around their play areas, LOL. The Monk, fwiw, only poops in one spot in night cage so clean up is a cinch compared to the Umb Cockatoo, LOL. One paper towel and done for the week 
The Nanday has zero debris other than shedded feathers to pick out, so that’s a cinch as well, thankfully. Sweeping the seed/Zupreem bits everyday can be frustrating, but its well worth it, of course. Dang Cockatoo would THROW his food literally across room when pissed/wanting to play, and what a mess, but off-topic, so…
A recollection I have that was quite funny and educational when I saw it on David Letterman back in mid-80’s on Stupid Pet Tricks segment comes to mind. IIRC, it was an Amazon (or similar-sized parrot) that owner said would poop in an exact area. Owner placed a smallish ‘hula-hoop’ on stage-front and told bird to do his thing. Bird flew and circled audience once (or twice) and then flared to slow over the hoop and deposited poop right in middle of hoop and flew back to owner’s arm in short order.
Dave cut the trick-contest short then and there as he stated that that could not be beat. Amazed me at that time, but since keeping large parrotiae, it’s not that surprising if bird is ‘taught’ to do such a thing. I may be misremembering a bit of detail, but it definitely was a crowd pleaser. Birds definitely use poop as a ‘tool’ when wanted, no doubt from my experience(s).
Fieldfares do (a European species of thrush):
“However the most characteristic defence is well-aimed defecation directed at the intruder.” (British Trust for Ornithology).
Search “fieldfares defecating” on Google (many results).
Also Hoopoe’s chicks when in their nestholes (personal experience).
This is off-topic, but kinda similar in behavior of ‘lower life forms’. Thought some might find it interesting in context of the thread.
Back in mid-80’s, a friend and I were sitting at a Barton Springs Park picnic table under a LARGE pecan tree on a hot summer day, enjoying some ‘smoking’ before we hit the cooling waters of the Springs and Campbell’s Hole upcreek. We could hear a number of squirrels overhead, no big deal. Suddenly, my friend got bonked on head by a half-eaten pecan. Excited happy-sounding chatter from squirrels above ensued. We thought it was random, but moved to other end of table, of course. Three more 1/2 pecans hit within a foot of us moments later. WTF?!?
We moved quickly to a table on far-side of other side of tree thinking the attack would stop. Nope. We watched as at least three squirrels scurried over us, way high in tree and the well-aimed bombs kept coming. We presumed that the squireels considered that place to be their foraging/personal space, and walked over to another shaded area.
Never imagined, at the age I was at that time, that a tree-rat would/could make ‘tactical’ decisions like bombing quite accurately with semi-ripe pecans, LOL. We were able to match up several ‘complete’ (fit together perfectly, per se) pecans from what was dropped so they were apparently biting the nuts in half to double their ammo.
I know squirrels are very good at figuring out how to get to something that’s juuuust out of their reach, but driving away persons with nuts from above was a first for me. Funny as heck if you could’ve seen us dodging the falling stuff while squirrels ‘laughed’ excitedly. Lil’ fuggers!