Is there a link between the size of an animal and its heart rate?

Yes. In general, smaller animals have faster heart rates than larger animals. Here are the heart rates of different organisms with varying body sizes :

1. A hummingbird's heart can beat up to 1,260 times per minute.
2. A small dog's heart rate is usually between 70 and 120 beats per minute.
3. An adult human's heart rate is typically between 60 and 100 beats per minute.
4. A horse's heart rate can be as low as 28 beats per minute.
5. An elephant's heart rate can be as low as 25 beats per minute.