A birds anatomy is quite unique and complex making it possible for them to fly great distances. important to focus on both parrot nutrition and weight. Birds require significantly more vitality than most animals.
Migratory birds are capable of flying at high altitudes where the air is thin. Most land dwelling animals are incapable of living at such high altitudes, but a birds lungs have evolved to allow them to engage in aerobic exercise with minimal oxygen! Our lungs are relatively large for our body size and contain ducts that flow into small sacs to feed oxygen to the lungs. Air enters the mouth or nose and moves down to the trachea where it is shuttled through a complex series of- bronchi, before finally entering the tiny air capillaries. Capillaries are where spent gases are exchanged with useful, needed gases through blood. Blood moves oxygen to all of the bodies cells.
In addition to lungs, birds have a number of air sacs in their torso. Pressure changes in the air sacs moves air throughout their system. The sternum to be pushed outward by muscles creating negative pressure in the air sacs and causing air to enter the respiratory system. Expiration requires certain muscles to contract to increase the pressure on the air sacs and push the air out. Because the sternum must move during respiration, it is essential to restrain your bird very gently. Holding a bird "too tight" during grooming may result in suffocation.
Bird lungs, on the other hand, operate quite differently. A birds lungs inflate but they don't deflate - they hold a constant volume of air. Visualize water flowing through a sponge. Air enters the birds lungs and then travels to nearby air sacs which function like bellows and push air through a birds lungs. Birds need their lungs to be steady in order to maintain altitude. Continuously inflated lungs enable a bird to maintain optimum altitude levels while allowing it to have significantly higher energy levels than mammals.
A birds respiratory system is much more efficient than that of mammals allowing more oxygen to be transferred with each breath. This efficiency means that toxins in the air are also absorbed more efficiently. If we breath the same concentration of toxins such as those from teflon, household cleaners and paint, we barely notice a problem. The same concentration for a pet bird, though, may be lethal.