Every birder who watches hummingbirds has marveled at their amazingly aerobatic flight abilities, but just how do hummingbirds fly? These tiny birds have unique flight mechanisms that give them a completely different style of flight than other birds, and understanding that flight can help all birders better appreciate the wonder that is a flying hummingbird.
Hummingbirds Fly Differently
While there are a number of flightless birds, most birds are adept fliers with somewhat specialized wing shapes and physical adaptations that make them the best fliers they can be, whether it is the broad wings of a soaring vulture, the pointed wings of an agile falcon or the rounded wings of a silently hunting owl. Hummingbirds, however, have far more unique flight abilities than any other bird, and are able to fly not only forward, but also backward, sideways and straight up. They can hover extensively – unlike short-term hovering birds like ospreys, kestrels, kingfishers and a select few other species – and can even do aerobatics such as backward somersaults as they dart among flowers searching for nectar and insects. The uniqueness of hummingbird flight has fascinated ornithologists for decades, but only with the advent of high speed filming and the use of advanced techniques to analyze the air currents around hummingbird wings and exactly how those wings move have scientists been able to better understand how hummingbirds fly.
Physiology of Hummingbird Flight
The unique physical adaptations hummingbirds have are key factors in why they fly so differently from other birds. Not only does their small size allow for better aerial maneuverability, but other physiological adaptations include:
- Hollow bones, fused vertebrae and fused pelvic bones to eliminate excess muscles and ligaments to lighten the bird's weight without sacrificing support that protects internal organs.
- Proportionally larger pectoral (chest) muscles and sternum that are responsible for moving the wings; a hummingbird's pectorals account for more than 25 percent of its body weight, a higher percentage than any other bird species.
- Minimal feet to reduce aerodynamic drag in flight and drop even more weight; a hummingbird's feet cannot walk, they can only perch or slightly scoot sideways.
- Longer, stronger bones in the "finger" portion of the wing to keep the wing stable with each stroke and to allow greater fine movements to control flight direction.
- An enlarged heart for more efficient pumping to support faster wing beats.
The Mechanics of How Hummingbirds Fly
Just physical adaptations are not enough to give hummingbirds such unique flight abilities. While most birds fly with upstrokes and downstrokes, generating all their lift and power on the downstroke of each wing beat, hummingbirds actually stroke their wings forwards and backwards, pivoting up to 180 degrees at the shoulder to rotate the wing. This pattern – the wingtip traces a horizontal figure eight in the air with each wing beat – generates lift on both forward and backward strokes, keeping the bird aloft and allowing it to hover. A minute twist can change the angle of the wing and influence the direction of flight, giving the hummingbird the ability to change direction instantly no matter which way the wing is stroking. This type of flight control is more closely associated with insects such as dragonflies than with birds, and is a unique adaptation the hummingbird has harnessed for efficient flight.
Ornithologists may have deciphered the gross mechanics of hummingbird flight, but much more research is needed to fully understand these birds' unique abilities. New research techniques involving ultraviolet light, wind tunnels and other advanced technology are continually improving our understanding of how hummingbirds fly.
Trivia Tidbits About Hummingbird Flight
How much more do you know about hummingbirds' flight abilities?
- Hummingbirds beat their wings from 8-200 times per second. Smaller hummingbirds beat their wings faster to stay aloft because of a smaller surface area to support their weight, and hummingbirds that are diving also beat their wings faster.
- A hummingbird can fly up to 60 miles per hour in a steep courtship dive, but speeds of 20-45 miles per hour are more common in straight, steady flight.
- Hummingbirds spend up to 90 percent of their flying time hovering to feed. Because this burns tremendous calories, these birds' nectivorous diet of sugar water is essential to give them enough energy to fly.
Providing perches for hummingbirds can give these birds a place to rest from their exhausting flight, and providing a reliable source of fresh nectar either with hummingbird-friendly flowers or clean hummingbird feeders will give them the energy to sustain their amazing flight. By understanding how hummingbirds fly, birders can be ready to help them stay aloft and enjoy every hovering hummingbird they see.
Want to learn even more about hummingbird physiology and trivia? Check out Do Hummingbirds Hum? and learn all about these popular birds!
Photo – Hummingbird in Flight © Dan Pancamo