How do birds fly?
Pro Research Analysisby 
Searched over 200M research papers
Understanding How Birds Fly
Bird flight is a complex and fascinating phenomenon that has intrigued scientists and laypeople alike for centuries. This article synthesizes recent research to explain the mechanics and strategies birds use to achieve flight.
Wing Mechanics and Aerodynamics
Wing Movement and Aerodynamics
Birds achieve flight through a combination of wing movements and aerodynamic forces. The primary forces involved are lift and drag. Lift is typically a vertical force that supports the bird's weight, while drag is a horizontal force that opposes thrust. However, birds can repurpose these forces during different phases of flight. For instance, during takeoff, birds incline their wing stroke plane to orient lift forward, aiding in acceleration, and drag upward to support their body weight. Conversely, during landing, lift is oriented backward to help with braking2.
Wing Shape and Function
Contrary to what one might assume, the shape of a bird's wing is not the sole determinant of its flight capabilities. Instead, the way birds swing their wings plays a crucial role. This dynamic movement allows birds to perform various flight behaviors, such as flapping, hovering, and soaring, without being limited by specific wing shapes1.
Flight Strategies
Intermittent Flight: Bounding and Undulating
Birds employ different flight strategies to optimize energy use. Two common strategies are bounding and undulating flight. Bounding involves bursts of active flapping followed by passive phases with folded wings, while undulating flight consists of active flapping interspersed with glides. Undulating flight is more energy-efficient at most speeds, whereas bounding is beneficial at very high speeds. These strategies allow birds to adapt to various flight conditions and conserve energy7 9.
Hovering
Hummingbirds are unique among birds in their ability to sustain hovering. This capability is due to their small size, high wingbeat frequency, and specialized wing anatomy. Hummingbirds generate lift during both the downstroke and upstroke of their wingbeats, although more lift is produced during the downstroke. They also exploit unsteady aerodynamic mechanisms, such as leading-edge vortices, to maintain hover9.
Formation Flying
V Formation
Some bird species, such as northern bald ibises, fly in a V formation to conserve energy. By positioning themselves strategically, trailing birds can exploit the aerodynamic upwash from the bird in front, reducing their own energy expenditure. This requires precise synchronization of wingbeats and a sophisticated understanding of aerodynamic principles10.
Cluster Formations
In contrast to the V formation, smaller birds like pigeons and starlings often fly in cluster formations. These groups exhibit rapid, synchronized changes in direction, creating a three-dimensional flight pattern. The mechanisms behind this synchrony are still being studied, but it is believed that a multidisciplinary approach involving biology, aeronautics, and computer science will be necessary to fully understand this phenomenon8.
Conclusion
Bird flight is a multifaceted process involving intricate wing mechanics, aerodynamic forces, and strategic behaviors. From the repurposing of lift and drag to the energy-saving strategies of intermittent flight and the sophisticated coordination in formation flying, birds have evolved a variety of methods to master the skies. Understanding these mechanisms not only satisfies human curiosity but also has practical applications in the design of advanced flying machines and unmanned aerial vehicles.
Sources and full results
Most relevant research papers on this topic
Wing swing, not shape, is key to bird flight
![Graphic][1] Be it finches flapping, hummingbirds hovering or seabirds soaring, birds are capable of achieving all manner of aerobatic approaches to flight. It would not be unreasonable to assume that these specialised flight behaviours would be associated with specific wing types, but, in
Rigorous JournalBirds repurpose the role of drag and lift to take off and land
Pacific parrotlets repurpose lift and drag during short, foraging flights, with low lift-to-drag ratios, suggesting avian precursors may have relied on drag to take off with flapping wings.
How Birds Fly
Birds fly by sustaining themselves with their wings, with the curvature of the wing surface acting as a slight propelling force.
Should We Care about how Birds Fly?
Bird flight has fascinated humans since the Stone Age, and the popularity of unmanned aerial vehicles (UAVs) has revived interest in bird-inspired air vehicles with flapping wings.
Bounding and undulating flight in birds
Undulating flight reduces energy at most speeds and allows birds to fly slowly most economically, while bounding flight only saves energy at very high speeds and does not reduce the mechanical cost of transport.
Highly CitedOrganized flight in birds
A multidisciplinary approach is necessary to understand organized flight in birds, as current hypotheses often contradict each other.
Highly CitedHovering and intermittent flight in birds
Hummingbirds can hover due to their small size, high wingbeat frequency, and energy-saving techniques, while small- and medium-sized birds use flap-bounding and flap-gliding for energy-saving and flexibility.
Bird flight: Fly with a little flap from your friends
Northern bald ibises fly in a V formation to conserve energy by regulating body position and synchronizing flapping motion.
Try another search
can red meat cause diabitis?
What are the latest discoveries in the human microbiome and implications for disease treatment?
What are the principles of game theory and its applications?
Does cannabis consumption benefit health?
does anaerobic ability affect peak blood lactate values
can we go back in time if we travel faster than light