How many times a second does a hummingbird wings beat?

Hummingbirds are amazing creatures known for their incredibly fast wing beats and ability to hover in midair. Their wings can beat up to 80 times per second, allowing them to fly forwards, backwards, upside down, and float in place. This rapid wing beat is necessary to generate enough lift to support their small bodies and power their aerial maneuvers.

What enables hummingbirds to beat their wings so quickly?

There are several key adaptations that allow hummingbirds to achieve such fast wing beats:

• Lightweight skeleton – Their bones are hollow which reduces overall body weight. This allows their wing muscles to accelerate and decelerate their wings quickly with each beat.
• Powerful flight muscles – Up to 30% of their total body weight is flight muscle, one of the highest proportions in the animal kingdom. More muscle means more power for each wing stroke.
• Rotating shoulders – Their shoulder joints can rotate a full 360 degrees which gives their wings great freedom of movement.
• Short, rigid wings – Hummingbird wings are relatively short and inflexible. This prevents drag from flexibility that would slow down each beat.
• Aerodynamic shape – Their streamlined shape and slender wings reduce air resistance on the downstroke and upstroke.

Together these adaptations allow hummingbirds to flap their wings extremely quickly with enough power on each stroke to create the lift and control needed to hover and dart swiftly between flowers.

How is wing beat frequency measured?

Recording and studying hummingbird wing beats requires specialized high speed cameras and analysis. Here are some techniques researchers use:

• High speed video – Recording at up to 1000 frames per second allows each wingbeat to be slowed down and examined.
• Stroboscopic illumination – Strobing a light source much faster than the wing beat frequency can “freeze” the motion for measurement and photography.
• Sensors – Tiny sensors have been attached to hummingbird wings or bodies to detect each muscle contraction.
• Sound recording – Some studies use microphones to record the sound of hummingbird wings for frequency analysis.
• Mathematical estimation – Wing shape and length can be used to mathematically estimate wing beat frequency based on aerodynamic factors.

By combining these techniques, researchers have been able to measure hummingbird wing beats across different species in various flight scenarios.

Average wing beat frequency by species

Wing beat frequency varies somewhat between hummingbird species due to differences in body size, wing shape, and flight style. But most species beat their wings approximately 40 to 80 times per second during normal forward flight. Here are average wing beat frequencies measured for some common hummingbird species during hovering:

As you can see, a range of 38 to 62 wing beats per second is typical among these common North American species. Larger hummingbird species such as the Giant Hummingbird of South America have slower wing beats around 12 per second.

How wing beat frequency varies during flight

Hummingbirds can modulate their wing beat frequency for different types of flight. Faster wing beats are used for hovering and slow-motion forward flight. Slower wing beats are used for higher speed forward flight. Here are some examples:

• Hovering – 60 to 80 beats per second
• Feeding on flowers – 40 to 55 beats per second
• Normal forward flight – 12 to 38 beats per second
• Fast forward flight – as low as 8 beats per second

Research has found that hummingbirds generally keep their wing beat frequency between 9 and 75 times per second depending on the maneuver being performed. The specific frequency used will also vary depending on a hummingbird’s size and wing morphology.

Why such rapid wing beats are necessary

Hummingbirds have evolved to beat their wings so quickly for two key reasons:

1. Hovering flight – To hover in place or drift slowly as they feed, hummingbirds need to generate enough lift to support their weight. Their small wing surface area requires rapidly beating wings to create that lift.
2. Maneuverability – Rapid changes in direction, speed, and orientation require responsive, quickly-accelerated wing beats. Slow wing beats would limit a hummingbird’s aerial agility.

The speed at which hummingbirds contract their flight muscles determines how fast they can control each wing stroke. This allows precise maneuvering and stability. Without their blazing fast wing beats, hummingbirds could not feed while hovering or dart swiftly between flowers and trees.

Hovering takes the most energy

Because hovering requires the fastest wing beats, it also demands the most metabolic energy. Hummingbirds have among the highest mass-specific metabolic rates in the animal kingdom. The Anna’s hummingbird has been measured consuming glucose at an average rate of 12.8 calories per gram of body weight per hour while hovering. This is approximately 10 times the fuel consumption per gram of an exercising human!

To meet these high energy demands, hummingbirds have evolved supercharged adaptations:

• Very high breathing rate – Up to 250 breaths per minute even while at rest
• Rapid heartbeat – Over 1000 beats per minute during flight
• High blood glucose levels – Some of the highest of any animals
• Tolerance for hyperglycemia – Blood glucose levels over 1% (other birds would go into a coma)
• Fast food transit – Liquids can transfer directly from the throat to the stomach in under a second

These remarkable physiological adaptations allow hummingbirds to sustain the physical demands of rapidly beating their wings all day long as they dart from flower to flower feeding.

Slow motion wing beats revealed

High speed cameras have provided fascinating insight into the precise motion of hummingbird wings during each beat cycle. Here is a typical wing beat in slow motion:

1. The wings clap together above the bird’s back at the top of the upstroke as the stroke reverses direction.
2. The leading edges separate as the wings pronate (rotate) to angle air flow for the downstroke.
3. At maximum pronation, the wings are almost vertical as they slice down through the air.
4. The wings rotate back as they reach the bottom of the stroke to catch air for the upstroke.
5. Near the end of each upstroke and downstroke, the wingtips trace an elliptical, circular, or figure 8 pattern called a “hover trace”. This provides lift throughout the stroke.
6. At the top of the upstroke, the cycle repeats at an amazing rate of up to 80 times per second!

This coordination of muscle contractions and small adjustments of wing position provides both the vertical lift and horizontal control that permit hummingbirds to hover and maneuver precisely.

Muscles driving the rapid beats

Two sets of powerful muscles control hummingbird wing movement:

• Pectoralis – This thick breast muscle pulls the wing downwards and forwards. It makes up 15-30% of a hummingbird’s body weight.
• Supracoracoideus – This smaller shoulder muscle lifts the wing upwards and backwards.

These muscles contract at incredible speeds to rotate the wing through each beat. For example, researchers measured over 200 contractions per second by the pectoralis muscle in Anna’s hummingbirds beating their wings over 50 times per second.

Interestingly, the pectoralis accounts for nearly all the power. The smaller supracoracoideus helps regulate the upstroke and flexibility but provides very little lift on its own. Without the pectoralis driving each downstroke, hummingbirds couldn’t generate enough lift to hover.

How hummingbird wings produce lift

Besides beating their wings rapidly, hummingbirds generate lift via these aerodynamic mechanisms:

• Leading edge vortex – At high angles of attack, a vortex forms over the wing. This low pressure zone creates lift to hover even at slow speeds.
• Wake capture – During the downstroke, the wings trap air pushed up by the wings, providing extra lift.
• Inverted camber – The wing cross section is curved at the front and flatter at the back to provide lift on both strokes.
• Wing rotation – Pronating at the top and bottom of each stroke angles air flow for better lift.
• Clap and peel – Clapping wings together at the top of the stroke may boost vorticity and lift.

Research is still revealing new details about exactly how the anatomy and movement of hummingbird wings generates enough lift for sustained hovering and maneuvering flight.

Conclusion

Hummingbirds are aerodynamic marvels. Their wings can beat up to an astonishing 80 times per second, providing the lift necessary to hover and the control necessary to dart rapidly in any direction. Slow motion footage has provided new insight into the complex motions involved in each wing cycle. While hovering demands the most rapid wing beats and burns the most energy, hummingbirds can modulate their wing frequency from around 8 to 75 beats per second to perform different flight maneuvers. This range of adaptability is what allows hummingbirds to utilize flower nectar as a food source – a feat unmatched by any other birds. Researchers continue studying hummingbird wings to better understand the biomechanics that enable their specialized flight capabilities.