Circulatory System

  A bird’s circulatory system pumps its blood through its body. Although this system is like that of other animals, birds’ hearts beat faster, and their blood is warmer.

  Like humans, a birds’ hearts have four chambers. Through tubes called arteries, the heart carries oxygen-filled blood away from the lungs. After the oxygen is used in various body parts, it is carried back to the lungs in veins.

  Birds’ hearts beat much faster than humans. For example, humans have a heart rate of 60-100 beat, while songbirds’ hearts beat 600 times per minute – and hummingbirds an amazing 1200! Because of this, birds receive oxygen to their body parts much more quickly, providing the energy needed for flight.

  Birds are warm-blooded animals, which means that their blood maintains a steady temperature. However, birds’ blood is warmer. For example, a human maintains a body temperature of 98.6º while a bird’s blood stays at 105º. This helps a bird remain active during cold weather.

  Additionally, birds have a special heat exchange system in their feet and legs. Because the blood vessels are close together and the blood  flows quickly back to the body, a bird’s feet don’t freeze when exposed to cold weather.

  A bird’s circulatory system is adapted to provide energy needed for flight and help them survive in low temperatures.