In February, our thoughts turn to love. Nature also puts a premium on the heart, but not just in February. Hummingbirds have the largest-known, relative heart size of all warm-blooded animals, yet it is only about the size of a dull pencil point! But it works hard, racing at a maximum of 1,260 beats per minute! By contrast, the blue whale’s heart weighs almost a ton. Find out how fast … or slow … it beats and learn more about the music of animal hearts on our podcast.