A Beating Heart / by Chris Maynard

 Cockatoo heart.

Cockatoo heart.

Happy Valentine’s Day! Who knows if heart symbol-shapes mean the same thing to birds as they do to us. Probably not. Even though birds’ hearts are similar in shape and function to ours, they are relatively bigger. They pump more blood and usually beat faster—a lot faster, 1250 beats per minute for an active hummingbird. But when a hummingbird rests at night, the heartbeat goes down to only 50 beats a minute! I wonder how much faster a hummingbird heart beats when it wakes up, and sees its mate, its valentine.