If there were a beauty prize for birds, the hummingbird would undoubtedly claim the first position. These birds, native to the North, South and especially Central America are Nature’s fire-flashing jewels. Their plumage is so brilliant that naturalists have given them the names of precious stones viz. Topaz hummingbird, Ruby-Throated hummingbird, Amethyst-Throated hummingbird, Fork-Tailed Emerald hummingbird etc. The brilliance of their feathers is produced by each barbule (a part of feather) which breaks up light like a prism.
Hummingbirds are the smallest of all birds and some of them are no larger than a medium-sized insect, weighing only about two to four grams. Yet this minute bird has the same parts of the body as any other bird: a heart, a stomach and a liver. Hummingbirds have special, vibrant way of flying, which produces a buzzing sound similar to that of bumblebees. Their wings beat so fast (50 to 70 times a second) that they become almost invisible to our eyes. Not only that, the hummingbird can also fly up, down, sideways, backwards and even upside down.
The reason they can achieve such exceptional flight patterns is that they can rotate their wings in a circle, creating power on the upstroke as well as downstroke. They are the only birds which can hover in mid-air. While hovering, the wings act like an oscillating helicopter blade with a steep angle of attack, forcing the air downward with both up and down strokes. This unique method of flight allows them to draw from flowers the nectar, which they collect as avidly as any insect.
Even though the hummingbird’s flying style may resemble that of an insect, but that is not the case. Hummingbirds are also the only type that can fly in reverse. Most birds are only able to either produce lift by using downstroke or upstroke. However, in the case of hummingbirds, it is the opposite. It has been found out that while a hummingbird is flapping its wings, 75% of its total weight is supported by the downstroke, whereas the other 25% by an upstroke. This unique pattern of flying can only be found in hummingbirds, thanks to their agile wings.
Additionally, the flapping motion of the hummingbirds is what they term as figure-8 motion. The wings of a hummingbird during a downstroke tilt forward and move down while pointing backward, twist over, and then go up for the upstroke. Hummingbirds can perform such aerobic acts due to the flexible shoulders they feature. Regular birds are not able to twist their wings, which would help them during the upstroke for lift, as they are neither able to reverse the relative airflow nor the camber.
The reversed camber is perhaps the most significant factor that provides hummingbirds a competitive edge against other flyers. It gives the bird an upward relative airflow instead of downwards, which helps it create the lift for managing and carrying its weight, ultimately allowing it to hover in mid-air.