I might be missing sonething here, but I have never seen a pigeon pluck him/her self. I do know that Parrots do. I have seen pigeons when preening them self, remove a loose feather but this is normal and quite common during the molt. I feel that many see this as plucking,but once again it is quite normal for a to remove a loose feather. I might add that healty pigeons will drop power down feathers(fluff) all year.This is also normal,in fact those of us that race pigeons look for this dropping of fluff feathers and good solid droppings as a sign of health and condishion. .GEORGE
