The air sac in birds seems to repair itself almost within a day or two, and if treated immediately, you can prevent the tear from enlarging. The avian respiratory system delivers oxygen from the air to the tissues and also removes carbon dioxide. Hope this helps! In most birds, the air-sacs (except the anterior and posterior thoracic, which never communicate with any cavity but that of the lungs) are in connection with a more or less extensively ramified system of air-passages, which may extend through a great many of the bones, and even give off subcutaneous sacs. It is the air sacs that move and pump oxygen through a complex bronchial network of a stationary lung. Birds have nine main air sacs that play an important role in respiration. However, birds do pay a price for the air sacs. The purpose of the air sacs in a bird is to help digest food into the gizzard, and to help it breathe, and stay in the air longer and more smoothly. Without air sacs, a bird would build up lactic acid during flight and may fall out of the sky when they cannot move their muscles any longer. Once your bird has been treated for an air sac rupture, and the ballooning effect is gone, it will recover remarkably well and continue with its normal life pattern. A bird’s lungs are static. With air sacs, birds can breathe in a lot more air than mammals, allowing them to fly.