It is difficult to fly forward, but nowhere to go, but it is so difficult to linger. Most bats and birds can only accomplish this task in a matter of seconds.
Hovering means losing a useful aerodynamic shortcut, says David Lentink, an aerospace engineer and biologist at Stanford University. When a bat or bird flies forward, its body movements allow air to flow around its wings and provide some cheap lift. This is a great help for animals of bats and birds. Without this ascension, “you have to move all the air onto your wings by moving it with your wings,” he said. By flapping your wings like a hummingbird, your energy consumption per second is “huge”.
So how do vertebrates looking for nectar manage this work? For these nectar, a lot of energy sucking is a part of life. For the first direct measurement of the flap force that makes hover possible, Lentink’s doctorate. Student Rivers Ingersoll spent three years building a flight chamber with responsive sensors on the floor and ceiling. When a bird or bat circles inside, the sensor can measure – every 200 seconds – vibrations caused by air from fluttering wings are even smaller than nanometers. Once the technological wonders of the instrument have been perfected, researchers have packed it into 11 boxes and transported it to more than 6,000 kilometers of field in Costa Rica.
A hummingbird circled near the flowers.
The twisted close hermit hummingbird gets some help by twisting its wings in the upper stroke.
Glenn Barry: WWW.GLENNBARTLEY.COM
“Very difficult,” admitted Ingersoll. The Las Cruces research station is well suited for field biology, but it’s completely different from Stanford’s engineering laboratory. Each vehicle enters the lane of the station, causing the wing beat sensor. Even the special thick-walled rooms that make up the machine’s second home are filled with heat every day to heat the instruments.
Ingersoll used the instrument wherever possible to measure directly 17 species of hummingbirds and three bats, including Glossophaga soricina. “Their sharp nose reminds me of rhino’s face,” he said.
Pallas’s bat focuses on nectar sipping, just like hummingbirds. However, comparing wing feathers, bats and birds reveals differences. Hummer plus powerful downlink and recovery uplink, almost reverses the partial wing. The distortion provides about a quarter of the energy needed to keep birds flying high, the researchers report in the September 26 issue of Progress in Science. The two nectar bats get more upgrade from the upgrade than the bats eat fruit, rather than spend a lot of bat wandering. However, even professional nectar bats rely primarily on the downward movement: the downward movement of powerful, deeply sloping, truly large wings.
Those bats have larger wings than the Hummer wings. Therefore, the hummingbird’s weight is about the same as that of a hummingbird. Super big can own its own high-tech design elegance.