Most believe that it is simply a defensive reaction caused by fright. There are two theories as to why they do this. One is that their excrement contains so much ammonium that it helps to kill bacteria. Another theory is that they do it to cool themselves. Despite these characteristics, they do have redeeming qualities.
Pairs are monogamous, and both parents incubate the eggs, as well as feed and care for the young.
Nest sites consist of little or no nest at all. Eggs are laid on debris inside a hollow tree or log, in crevices on cliffs, and in caves, dense thickets or old buildings. Usually, two whitish eggs, blotched with brown and lavender, are laid. Incubation lasts 34-41 days. Young are born with a coat of down and open eyes but must be fed by their parents' regurgitation.