Heart

Blue-throated hummingbird Lampornis clemenciae Credit: Ross Tsai (Size: 54.00 kb)

The heart of a hummingbird constitutes 2 to 5% of its body mass, whereas the equivalent in songbirds is 1 to 3% and 0.5% in primates. A hummingbird's heart can beat from 500 to 600 times a minute when at rest and up to 1000 a minute in extreme conditions. In the Blue-throated Hummingbird (Lampornis clemenciae), 1260 beats a minute have been recorded. This high heart rate allows hummingbirds to achieve the high volume of oxygen required for their lifestyle. In comparison, the ostrich has a heart rate from 40 to 180 beats a minute.