In the entire animal kingdom, the only birds that can fly in various directions are hummingbirds, of which there are 47 species in Latin America.
After several months of observing hummingbirds sitting on the balcony of his house, Nir Sapir, an evolutionary biologist, and researcher at the University of Haifa realized that they had the ability to fly in various directions. The speed of flight, in such small animals, managed to capture their attention.
From this experience, he met with Robert Dudley, from the University of California, to carry out research work hand in hand with Berkeley. For this study, focused on the flight of hummingbirds, they used high-speed cameras and oxygen consumption meters. This is what they discovered.
Up, down, forward and backward
For the study, the flight of five hummingbirds in captivity was considered. They belonged to the Calypte anna species, which is characterized by having redheads, who were fed one by one on sugar while the team activated a wind tunnel. In this way, they could control and manipulate the intensity of the artificial breeze, to observe the behavior and reaction of the animals.
They found that by altering the strength and direction of the wind, the birds used different flight strategies. The movement was recorded by high-speed cameras, while the hummingbirds’ oxygen consumption, posture, and the plane of inclination of their wings were measured.
This last factor was the determining factor in the research since they realized that these birds have the ability to go forward, backward, up, down, or stay in the same place.
By observing them, they realized that they fly backward when they retreat from some flower that they used as a source of nectar. By then, there was not much research regarding the flight of hummingbirds, as Sapir says:
“I WATCHED THE HUMMINGBIRDS IN A FEEDER ON MY BALCONY AND SAW THAT THEY FLEW BACKWARDS FREQUENTLY. THIS SURPRISED ME A LOT CONSIDERING THAT THEY FLY BACKWARDS ALL THE TIME, SO I DECIDED TO STUDY HOW THEY DO IT AND WHAT CONSEQUENCES THIS TYPE OF FLIGHT HAS ON THEIR METABOLISM”
This explains why these tiny birds look for flowers to feed every two minutes. Apparently, they require a significant energy boost, because they have to recover from the expenditure so important for their bodies.
In addition, it turned out that the resistance they impose in the air is slightly higher than in forwarding flight. This, according to Sapir, corresponds to the fact that the speed decreases when they head backward. The full findings were published in the Journal of Experimental Biology.