Most Acrobatic Birds on Earth(Swifts and Humming Birds)
Swifts and Hummingbirds share a special type of wing that makes them the most acrobatic of birds. Their “wrist” and “elbow” joints are very close to the body and their wings rotate at the shoulder.
This gives superb flexibility and a very rapid wing-beat. Swifts are among the fastest birds in level flight and can stay airborne for years. Hummingbirds can hover motionless and fly backward or even upside down. To fuel their aerial stunts, these birds need a lot of food. Swifts trawl the air with their mouths agape to catch tiny midges;hummingbirds use their long bills to suck nectar from flowers.
The European swift is the world’s most aerial animal and can stay airborne for two years at a time. It eats, drinks, sleeps, mates, and gathers nest material entirely on the wing. Its tiny legs are so weak that it cannot walk, but it can cling to vertical surfaces.
BEHIND THE WATERFALL
South America’s great dusky swift builds its nest behind a waterfall and can fly straight through the raging torrent to reach it. Swifts can’t land to gather nest material, so they build nests from a mixture of sticky spit and fluffy materials caught in the air. The nests of certain swifts are considered a delicacy in China and are boiled to make soup.
A LIFE ON THE WING
Swallows and martins are not close relatives of swifts, but they have a similar shape and they also feed during flight. Their pointed wings and forked tails help them twist and turn with breathtaking agility as they chase flying insects one by one. They also drink on the wing, swooping low over ponds to take mouthfuls of water.
Hummingbirds build tiny but deep cup-shaped nests from moss and spider’s silk. The outside may be decorated with lichen for camouflage, and the inside is lined with soft fibers. The bee hummingbird’s nest is the size of a thimble.
The male bee hummingbird of Cuba is only 2.2 in (5.7 cm) long from bill to tail, making it the world’s smallest bird. To stay airborne, it must beat its wings an amazing 200 times a second, which produces a buzzing sound like a bee.
Hummingbirds fly in a different way from other birds, twisting their wings back and forth in a figure-eight pattern instead of lapping them up and down. This motion allows a hummingbird to hover and stay perfectly still before pulling out of a flower. But the wings are short and must beat very quickly, which uses a great deal of energy.
FUELED BY NECTAR
Hummingbirds use energy so quickly that they must visit up to 2,000 flowers a day. In doing so, they unwittingly spread pollen
between flowers and so help plants to reproduce. At night, hummingbirds go into a kind of hibernation to conserve energy.