Hummingbirds are amazing creatures. They are the smallest birds in the world, yet they are capable of incredible aerobatic feats. Their ability to hover in midair and rapidly change direction seems to defy physics. So how do these tiny birds fly in a way that is so different from other birds?
How Do Hummingbirds Hover?
Hummingbirds are the only birds that can fly backwards. They can also hover in midair and rapidly change direction. This is because their wings are able to rotate in a full circular motion. Other birds’ wings cannot twist in this way, so they cannot hover or fly backwards.
When hummingbirds hover, their wings beat in a figure-8 pattern. On the downstroke, the wing is angled slightly backward. This pushes air down to create lift. At the bottom of the stroke, the wing rotates so that the leading edge faces forward. On the upstroke, the wing cuts through the air horizontally to minimize drag. At the end of each cycle, the wings rotate again to push air down on the next downstroke.
Hummingbirds beat their wings up to 80 times per second. This allows them to generate enough lift to stay suspended. The rapid wing movement also enables instantaneous changes in direction, altitude, and speed.
How Do Hummingbirds Maneuver so Quickly?
Hummingbirds’ remarkable aerial agility is due to their ability to alter the angle of their wings during each stroke. By changing the angle of attack, they can generate force in any direction—up, down, forward, backward, left, or right. This allows them to dart from flower to flower, hover in place, fly upside down, and even glide sideways or backwards.
Hummingbirds have very flexible shoulder and wrist joints compared to other birds. This allows their wings to bend and twist with great precision. A hummingbird can rotate its wings 180 degrees during a single stroke. Other birds’ wings cannot flex beyond 90 degrees.
By adjusting the position of their wings on each stroke, hummingbirds can manipulate their aerodynamic forces. For example, by increasing the angle of attack on the downstroke, they can produce more lift to ascend rapidly. By decreasing the angle on the upstroke, they can minimize drag. This gives them excellent acceleration and braking abilities.
How Do Hummingbirds Fly with Such Small Wings?
Given their extremely small size, it seems miraculous that hummingbirds are able to fly at all. The largest hummingbird species have a wingspan of about 8 inches. The smallest species measure just 2.5 inches across. Yet they are strong, agile fliers.
Hummingbirds compensate for their small wings in a few key ways:
- Their wings flap at incredibly high frequencies, generating sufficient lift.
- Their lightweight bodies require less lift to stay airborne.
- Their wings are proportionally larger compared to their bodies than other birds’.
- Their wing shape enables versatile motion and lift generation.
Additionally, hummingbird wings have multiple flexible joints that allow changes in angle of attack during each stroke. This lets them shape their wings precisely to control lift. The differences in lift between upstroke and downstroke allow sustained hovering.
How Fast Do Hummingbirds Fly?
Hummingbirds are remarkably fast fliers for their size. Here are some top speeds of hummingbird flight:
- Diving speed – At least 60 mph
- Courtship display dives – Up to 60 mph
- Maximum horizontal flying speed – 30 to 40 mph
- Routine horizontal flying – 15 to 30 mph
- Wing flapping during hovering – 50 to 80 flaps per second
The fastest dive speeds measured exceed 60 mph in some large hummingbird species diving from high altitudes. Smaller species may not reach these speeds. However, relative to their body size, even small hummingbirds achieve impressively fast flight.
Hummingbirds can accelerate and maneuver remarkably fast thanks to their lightweight bodies and adjustability of their wings. By changing the angle of attack dynamically, they can produce aerodynamic forces necessary for their agile movements.
How Much Do Hummingbirds Weigh?
Hummingbirds are the smallest birds in the world. Here are typical weights for a few common hummingbird species:
Species | Weight |
---|---|
Ruby-throated hummingbird | 2.4 – 3.4 g |
Black-chinned hummingbird | 2.2 – 3.4 g |
Rufous hummingbird | 2.4 – 3.9 g |
Broad-tailed hummingbird | 3.1 – 4.7 g |
Blue-throated hummingbird | 5.8 – 8.5 g |
To put their tiny sizes into perspective, a penny weighs about 2.5 grams. The bee hummingbird, the smallest bird species in the world, weighs just 1.6 to 2 grams.
Being extremely lightweight allows hummingbirds to hover and fly with minimal effort. Their light bodies require less lift to become airborne and less energy to stay aloft.
How Much Food Do Hummingbirds Eat?
Hummingbirds have extremely high metabolisms. To power their energetic lifestyles, they need to consume a tremendous amount of energy in the form of nectar, tree sap, and insects each day.
A hummingbird may consume over half its body weight in nectar per day. Given that they weigh only a few grams, this translates to taking in multiple times their weight in just nectar daily.
Research shows that broad-tailed hummingbirds eat approximately 12 to 17 calories per day. For a 3.6 gram bird, that would be 3,300 to 4,700 calories per kilogram of body weight. In human terms, that would equate to a 150 pound person consuming over 250 pounds of food per day!
Hummingbirds also consume tree sap and small insects, including gnats, fruit flies, aphids, and spiders. These high-protein foods provide essential nutrition to supplement the mostly sugar-based nectar diet.
How Do Hummingbirds Feed While Hovering?
Hummingbirds have an amazing ability to precisely control their position in space, allowing them to feed while hovering in midair. Here are some key ways they maintain stability:
- Their wings beat in a symmetrical figure-8 pattern that enables precise lift control.
- They dynamically adjust wing angles to shift their aerodynamic forces as needed.
- Their tail feathers help control roll and yaw movements.
- Their feet can be angled to provide lift if they start to lose vertical stability.
Hummingbirds also have anatomical adaptations that help them feed on hover. Their bill shape allows them to precisely insert their tongues into flowers. Their retractable tongues have forked tips covered in hair-like filaments that soak up nectar.
They extend their tongues up to 13 times per second when feeding. Their tongues even have tubes that allow nectar to move from the tongue tip to the throat without swallowing each time.
How Do Hummingbirds Mate and Nest?
Hummingbirds engage in elaborate courtship rituals centered around fast flying and diving to impress potential mates. Here is how they mate and nest:
- Males perform dramatic courtship dives up to 60 mph to impress females.
- If receptive, females may join in the diving display before copulation occurs in flight.
- Females build a tiny nest out of soft plant down, spider webs, and lichen using their feet and bill.
- Nests are only 1.5 to 2 inches wide and may be decorated with lichen or moss on the outside.
- The female lays 1 to 3 pea-sized white eggs and incubates them for 2 to 3 weeks.
- Chicks hatch, are cared for by the female for 2 to 4 weeks, and fledge from the nest.
Hummingbird nests are engineering marvels. They expand to hold the growing chicks and can perch on branches in rain and wind. At the same time, they are made of supple, stretchy materials that provide just enough give to cushion the eggs.
How Do Hummingbirds Survive Cold Weather?
Hummingbirds have an incredible ability to survive cold temperatures given their tiny size. Here are some strategies they use:
- They accumulate extra body fat before winter to provide energy reserves.
- They reduce their metabolic rate and heart rate to conserve energy.
- They enter torpor, a short-term hibernation, at night to save energy.
- They fluff their feathers for maximum insulation.
- They seek shelter in tree cavities, thick vegetation, or other protected areas.
Research shows hummingbirds can slow their heart rate to as little as 50 to 180 beats per minute overnight when torpid. Their normal daytime heart rate is around 500 to 600 bpm. This allows them to conserve a tremendous amount of energy when food is limited.
Some hummingbirds also migrate hundreds or thousands of miles to warmer climates for the winter. Their navigation abilities during migration are impressive given their tiny size.
How Long Do Hummingbirds Live?
In the wild, most hummingbirds have relatively short lifespans. However, some captive hummingbirds have been known to live surprisingly long lives.
- In the wild: 3 to 5 years
- In captivity: 5 to 10 years
- Record lifespan: 12 years
Threats to hummingbirds’ survival in the wild include starvation, cold stress, predators, diseases, collisions with vehicles and buildings, and habitat loss. With abundant food sources and protection from threats, captive hummingbirds may far outlive their wild counterparts.
Interestingly, hummingbirds seem to lack signs of aging observed in other birds and mammals. Even after reaching advanced age, they do not lose flight capabilities or suffer dementia typical of aged animals. Some scientists think hummingbird metabolism may slow aging effects.
Conclusion
Hummingbirds are remarkable creatures with evolutionary adaptations allowing sustained hovering flight and extreme aerial agility unmatched by other birds. Their tiny sizes, versatile wing motions, rapid wing-flapping, and lightweight bodies enable capabilities that seem to defy physics. Ongoing research continues to reveal new aspects of how these colorful, energetic birds survive and thrive in diverse environments.