Gas-exchange in birds

Gas-exchange in birds

Birds take two full breaths of air for respiration. The first inhalation goes to the posterior air-sacs. During the next inspiration and expiration, this air travels through the lungs to the anterior air-sacs and new air enters the posterior air-sacs. Then, the initial air is exhaled out during the next breath. This allows the bird to attain more oxygen than a mammal.