Do Hummingbirds Hum?
West, George C / Butler, Carol A
Hummingbirds may be the smallest birds in the world, but they have the biggest appetites. Their wings flutter on average 50 to 80 times each second as they visit hundreds of flowers over the course of a day to sip the sweet nectar that sustains them. This work offers an overview of hummingbird biology, discussing their morphology and behavior.