by Pajarita » Thu Jun 06, 2013 3:29 pm
I agree with CML, it's mostly ignorance that fuels the clipping thing. Birds need to fly. Period. Their respiratory system is infinitely superior to ours because the 'dirty' air doesn't mix with the 'clean' air in their lungs (as it does in ours). They needed a higher efficiency in terms of oxygen (for their flying) so Nature made it so their respiratory system doesn't mix the clean air with the dirty and, to achieve that, it gave them not only lungs (as mammals have) with 'closed' alveoli (these are the little thingies at the very end of the bronchi -little tubes that carry the air into and throughout the lungs- and where the oxygen is absorbed into the blood) but a more complex system where the air goes into the lungs but doesn't come out (as when we exhale) right away, it goes into one set of air sacs after another until it comes out (that's why they cannot cough like mammals do). Now, there are two problems with this system: one is that the lungs are not elastic like ours, they are quite rigid, and they don't have a diaphragm to 'bellow' the lungs so the only way that the air goes from one set to another is through pressure (they take a breath and the air goes into the lungs and, with the next breath, the new air pushes the 'old' air in the lungs into the first set of air sacs which in turn pushes the air they are 'holding' into the second set and so on and so forth) and the other is that they all communicate with one another (that's why it's called an 'open-ended' system) so if one set gets infected, they all get infected. The last set is actually the only one that has a sort of 'bellowing' action and this is caused by the muscles of the wings when they go up and down in flight. No flight, no 'bellowing' action on the last set of air sacs which means that the only way the air can come out is through the pressure created by the new air that came in -which sounds fine to us but it's not because it only allows for a limited amount of movement. This limited movement creates an atrophy and any organ that is not working as it should and becomes partially weakened or atrophied creates a fertile ground for infection (not my opinion but a scientific fact). And then, because the lungs and the air sacs are all connected, if one set gets infected, they all get infected. And that's why birds that don't fly have respiratory infections so often.
A clipped bird is NOT a healthy bird. And I am only talking physical health and not even going into the emotional problems it creates (birds fly away when they feel danger -you know, the 'fight-or-flight' response, aka 'acute stress response'- but a clipped bird cannot fly away which causes terrible stress to the poor animal).