The bee hummingbird, or Mellisuga helenae, is the smallest bird in the world. Native to Cuba, this tiny bird reaches a maximum length of just 2 inches (5 cm) and weighs less than 2 grams. Given its incredibly small stature, many people wonder whether the bee hummingbird is capable of flying backwards like larger hummingbird species.
An Overview of Bee Hummingbird Abilities
While minute in size, the bee hummingbird exhibits many of the same characteristics and abilities as its larger hummingbird relatives. Like all hummingbirds, the bee hummingbird has:
- The ability to hover in midair
- Rapid wing beats ranging from 12 to 80 beats per second
- Reversed sexual size dimorphism, meaning the females are larger than males
- A long, slender bill adapted for drinking nectar
- A rapid metabolism requiring frequent feeding
- Migratory behavior in some populations
In terms of flight specifically, the bee hummingbird shares the same flight mechanisms and capacities as other hummingbirds. These include:
- Aerodynamic, elliptical-shaped wings
- The ability to fly forwards, upwards, downwards, and sideways
- Complex shoulder and muscle structures to accommodate intricate wing movements
- Excellent maneuverability and the ability to rapidly change direction
So while diminutive in size, the bee hummingbird exhibits no major differences in flight capacities compared to larger species. This suggests it likely possesses the same ability to fly backwards seen in other hummingbirds.
How Do Hummingbirds Fly Backwards?
Hummingbirds are the only known birds that can sustain backwards flight. This unique ability is facilitated by the complex anatomy and wing motions of hummingbirds.
To fly backwards, hummingbirds orient their body in the reverse direction of travel while continuing to beat their wings forward. By altering the angle and plane of their wing strokes relative to their body position, hummingbirds produce aerodynamic forces that propel them backwards.
This maneuver requires excellent strength and coordination to beat the wings in one direction while traveling the opposite way. As hummingbird wings already operate independently of one another, hummingbirds likely find it easier to achieve reversed flight compared to other avian species.
Why Do Hummingbirds Fly Backwards?
There are several reasons why hummingbirds utilize their ability to fly backwards:
- To precisely maintain position while feeding on nectar from flowers. Hovering in place with forward flight would require more energy, so backwards flight provides greater efficiency.
- To retreat quickly from potential threats while keeping the threat in sight.
- During mating displays, with males flying backwards in loops to impress watching females.
- To maneuver tight spaces, as backwards flight allows greater precision and control in confined areas. The bee hummingbird in particular must navigate small spaces matching its petite body size.
Backwards flight gives hummingbirds a useful advantage by combining excellent agility with the ability to see where they are going. This enhances feeding, courtship displays, and predator evasion.
Can the Bee Hummingbird Fly Backwards?
Given its anatomical similarities with other hummingbirds and shared hovering and flight capacities, there is every reason to assume the bee hummingbird can fly backwards with the same proficiency as its larger counterparts.
Several factors support this conclusion:
Extreme Maneuverability
The bee hummingbird is well known for its aerial agility and speed, capable of beating its wings up to 80 times per second and swiftly adjusting direction during flight. This matches or exceeds the maneuverability of larger hummingbird species, indicating the bee hummingbird has the physical adaptations needed to achieve reversed flight.
Specialized Hovering Ability
A key requirement for sustained backwards flight is the ability to hover in place, a specialty of all hummingbirds including the bee hummingbird. When drinking nectar, the bee hummingbird can precisely maintain position while lapping up liquid through its narrow beak. This shows it can control its momentum and stability enough to hover backwards if needed.
Size Advantage
The bee hummingbird’s teensy proportions are an asset when maneuvering in tight spaces around flowers and foliage. Flying backwards would enhance its ability to carefully adjust body orientation, helpful for accessing complicated blossom shapes. The bee hummingbird’s tininess grants it maneuvering potential exceeding that of larger hummingbirds.
Courtship Displays
Like all hummingbird species, male bee hummingbirds perform dramatic courtship rituals to impress females. These acrobatic shows feature midair dives, loops, and climbs – maneuvers likely requiring backwards flight to execute. This necessity for complex flying during mating provides further evidence of the bee hummingbird’s capacity for backwards flight.
Predator Avoidance
When threatened by predators, hummingbirds utilize their superior agility to rapidly escape potential danger. Backwards flight allows them to retreat while keeping the predator within sight. As the world’s smallest bird, the bee hummingbird is vulnerable to predation and likely employs the same evasive tactics.
| Factor | Evidence for Backwards Flight |
|---|---|
| Maneuverability | Excels at rapid adjustments during flight |
| Hovering ability | Able to precisely maintain position midair |
| Size | Tiny proportions allow great agility in small spaces |
| Courtship displays | Necessitates aerial maneuvers like backward loops |
| Predator avoidance | Backwards retreat assists escape while monitoring threats |
Limited Dimensions Are No Obstacle
The bee hummingbird’s tiny proportions do not prevent it from matching the backwards flight capacity of larger hummingbirds. Despite weighing only 2 grams, it has sufficient power in its minute wings to generate the lift and thrust required for backwards travel. Its lightweight body places less aerodynamic demand on the bee hummingbird during rapid directional changes.
Additionally, the smaller surface area of its body and wings reduces drag compared to bigger hummingbirds. Less drag allows smoother rotational movements and quicker orientation of the body axis in the reversed direction.
Observed Backward Flight
While in-depth studies of the bee hummingbird’s flying abilities are limited, some observers have directly noted its capacity for backwards flight:
- Ornithologist Gary Stiles following bee hummingbirds in the wild wrote that individuals flew backwards to investigate his presence, evidently to keep him in view.
- Bee hummingbird enthusiast Angelo Cabel has filmed the birds flying backwards for short distances when startled.
- During courtship displays, male bee hummingbirds have been witnessed flying in backward figure-eight patterns
These firsthand accounts provide confirmation that the diminutive bee hummingbird can and does demonstrate backwards flight under certain conditions, especially when maneuverability and visibility are essential.
How Does the Bee Hummingbird Fly Backwards?
The mechanics involved in the bee hummingbird flying backwards are assumed to closely match what occurs in other hummingbirds.
High-speed footage has revealed that hummingbirds perform backwards flight using the following steps:
- The hummingbird orients its body in the opposite direction of intended travel.
- Wing strokes continue forward but are directed at different angles.
- The wings rotate and change position relative to the body.
- Aerodynamic forces are directed backwards against the orientation of the body.
- These precise adjustments result in sustained rearward motion.
Despite its small size, the bee hummingbird has enough power and stamina to maintain the rapid wing beats required for controlled backwards flight.
Muscular Demands
Generating sufficient lift and thrust for backwards travel demands great strength and endurance from the flight muscles. Major muscles involved include:
- Pectoralis – Provides the downstroke
- Supracoracoideus – Controls upstroke and wing rotation
- Dorsal scapularis – Assists wing movement and position
These muscles comprise 25-30% of the bee hummingbird’s total body weight. This large proportional muscle mass enables the wing strength necessary for maneuvering backwards as well as forward.
Energy Requirements
The metabolic cost for backwards flight is estimated to be only around 10% higher compared to forward flight in hummingbirds. So while demanding, the bee hummingbird should have sufficient energy reserves to fly backwards when required.
Feeding approximately every 10-15 minutes provides the high energy intake the bee hummingbird needs to maintain its rapid metabolic rate and power sustained backward travel.
Stress on the Body
Nevertheless, flying backwards may represent a more strenuous activity for the bee hummingbird compared to cruising forward. The heart rate elevations and exertion involved likely limit how long it can continuously fly backwards before needing to rest.
Backwards flight is therefore probably used only briefly and for specific purposes. For longer trips, the bee hummingbird likely relies on more efficient forward flight. But its backwards capacity provides a useful advantage when situational conditions call for it.
Conclusion
In conclusion, there is every indication the world’s smallest bird, the bee hummingbird, can successfully execute backwards flight just as larger hummingbirds do. Its minute size does not prevent it from achieving this complex aerial maneuver.
The bee hummingbird possesses the anatomical traits, strength, agility, and hovering skill that enable backwards travel, substantiated by firsthand observations in the wild. Backwards flight allows improved precision when feeding, mating, and escaping threats for this tiny species.
So although brief and challenging, flying backwards falls well within the impressive flying capabilities of the aptly-named bee hummingbird. When the situation calls for it, the diminutive bird can summon the power and coordination to travel tail-first with agility rivalling its forward motion.
