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. Understanding that flight can help all bird aficionados 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. Many birds have specialized wing shapes and physical adaptations that make them better fliers, 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 as they are able to fly not only forward, but also backward, sideways, and straight up. They can also hover extensively, much longer than short-term hovering birds like ospreys, kestrels, kingfishers, and a select few other species. Hummingbirds 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. Today, the use of high-speed filming and advanced techniques to analyze air currents around hummingbird wings have allowed scientists to better understand how hummingbirds fly.
The unique physical adaptations of hummingbirds are key factors in why they fly so differently from other birds. Not only does their small size allow for better aerial maneuverability, but they also have many other physiological adaptations that make them superior fliers.
- Hollow bones, fused vertebrae, and fused pelvic bones eliminate excess muscles and ligaments to lighten the bird's weight without sacrificing support that protects internal organs.
- Proportionally larger pectoral (chest) muscles are responsible for moving the wings. A hummingbird's pectoral muscles account for more than 25 percent of its body weight, a higher percentage than any other bird species.
- Minimal feet 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 keep the wing stable with each stroke and to allow greater fine movements to control flight direction.
- An enlarged heart for more efficient pumping supports faster wing beats and more efficient oxygen distribution to the muscles.
The Mechanics of Flight
Physical adaptations alone are not enough to give hummingbirds such unique flight abilities. Most birds fly with upstrokes and downstrokes, generating all their lift and power on the downstroke of each wing beat. Hummingbirds, however, stroke their wings forward and backward, pivoting up to 180 degrees at the shoulder to rotate the wing. This pattern, with the wingtip tracing 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 flight direction, allowing the hummingbird 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 technology are continually improving our understanding of how hummingbirds fly.
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. Hummingbirds that are diving also beat their wings faster than in typical, level flight.
- 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' diet of high-calorie sugar water is essential to give them enough energy to fly.
Providing perches for hummingbirds can give them a place to rest from their exhausting flight. At the same time, providing a reliable source of fresh nectar with hummingbird-friendly flowers or clean hummingbird feeders will also 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.