What is the number of chambers in a bird?

Birds have a four-chambered heart, consisting of two atria and two ventricles. This arrangement is more efficient than the three-chambered heart found in reptiles and amphibians, as it allows for the complete separation of oxygen-rich and oxygen-poor blood. This means that birds can deliver oxygenated blood to their tissues more efficiently, allowing them to maintain a higher body temperature than other cold-blooded animals. It also permits them to fly effectively as their muscles require a lot of oxygen.