Re primary reason
Jiggs,
I'm going to get picky here, because I think it important to emphasize the point I was trying to make, and because I think you may have misunderstood me. (It is not so important that I be understood. I think my statement as I intended it to be understood is important).
I said the PRIMARY reason, that is, the main reason, the most important reason, in other words, that birds avoid their poop is to keep it off their feathers. I am not excluding or negating other reasons, which I think are of secondary or lesser importance.
I would love to have an argument or a discussion if someone thinks that there is a more important reason why birds go to the trouble to avoid getting poop on themselves.
A bird whose feathers are gummed up, stuck together, glued together, or call it whatever you like, by poop, is a bird in trouble. It would have trouble keeping is feathers in top shape so that it could fly and escape or avoid danger. Any other reason, I maintain, is secondary to that reason.
If anyone can point out a better or more important reason, I will happily be willing to concede the point and be grateful for the education.
I like to argue or disscuss, not to upset anyone or to get in a battle just for the sake of fighting, but as a means and a tool for learning.
There may be more important reasons which I am not aware of, because my observations are based mainly on watching a few nestllngs close up in domestic quarters, and not birds in the wild.
That's why I say "I" and "think" ....
I am not saying that "(quoted authorities) state for a fact that...."
I removed a golf-ball sized mass of poop off of the pigeon Splitbeak, who could nor clean herself properly because of a missing upper beak (the left upper beak flopped around to the left side, the upper right beak was missing). The poop had been caused by a build-up of diarrhea, which I think was caused by a bout of illness from bad nutrition (and which Pigeonperson recently pointed out may have been caused by kidney malfunction). The poop stuck to her keel, near the vent. Splitbeak had feathers stuck in the poop, and as the feathers attempted to grow out, they broke off close to the skin. A baby bird with poop on its young feathers and sticking them together would also have painful problems with feather growth, and be handicapped. In like manner, a kid can have chewing gum in his hair, but it is not going to cause major problems of the same degree.
Splitbeak was still able to fly with 50 to 60 grams (two ounces) of poop hanging from her lower torso, but it added to her weight of 240 grams (if I remember her weight correctly) and meant that she avoided flying with the flock when raptors flew overhead, and either crouched still, or made a dash for the church scaffolding nearby where she slept. When she walked she took short steps, because she could move her legs forwards but not backwards further than straight underneath her, where they thudded against the mass of poop. It took me almost an hour in the shower with her to remove the rock-candy-hard mass of poop after she became weak enough for me to catch in July 2005.
It's getting late here, and I'm pooped.
Larry