A rain might just get you wet, but imagine what if you were as small as a sparrow or a hair bob? To them, flying in the rain was like walking in the midst of a wave of bombardment that slanted diagonally into the air.
When a bird or insect gets stuck on its wings by water, they will fall because they cannot fly anymore. And if such a frightening rain, waterfalls must be impregnable walls for small creatures.
However, scientists were surprised to discover that some insects and small birds can overcome this natural barrier. They have practiced special skills to be able to fly through falling waterfalls.
The reason these creatures do that is because they have the custom of building nests behind waterfalls. For small birds, it’s a safe haven separate from the world and outside predators.
The flying behavior of cutting through waterfalls of some small insects and birds is now a special subject of study for scientists. They set camera traps to capture impressive slow motion footage, showing the ingenuity and clever strategy of small creatures flying through a stream of water.
The video above shows a hummingbird Anna (Calypte anna) flying through the waterfall. Two camera angles show that it has used a very ingenious and intelligent strategy. First, the hummingbird will first pass through one wing through the waterfall, keeping the other dry outside.
After the first wing passed through and rinsed the water, it pulled the second wing through the waterfall. The bird was only slightly flung in this cross-water flight. It basically never lets both wings get wet at the same time.
If we just used our knowledge without the video footage, we wouldn’t be able to guess what hummingbirds would do in this situation, says Victor Ortega-Jimenez, study author and a biologist from Kennesaw State University said.
At first, scientists thought the birds would close both wings and cross the water, with their heads and bodies. It can be a quick dash through the falls to reduce contact area and time. But with these new footage, it’s clear they were wrong.
The bird passed each of its wings forward like a person leaning in a sloping swim. The entire traverse takes only 100 milliseconds.
Hummingbirds are very small creatures. They weigh only 4.5 grams on average but are very weather resistant. Hummingbirds can fly through heavy rain, high winds, and even bathe in lakes at the base of falls.
Together with the bird’s nest nesting behind the waterfall, it seems hummingbirds also built for themselves this practice to avoid facing the enemy. Many other birds such as starlings and small-looking worms also possess this practice.
That’s what biologists have known for a long time. But for physicists, they are interested in how birds get through waterfalls. To be able to study that, scientists at Kennesaw State University created artificial cascades in the lab.
They then catch hummingbirds and train them by placing the food box behind the waterfall. High-speed cameras are placed in multiple angles to capture the bird’s flight to get food.
In addition to hummingbirds, scientists also captured a number of insects to try to lure them through the waterfall with light. They light a light behind the falls and to the insects, a light is more attractive than food.
The smaller the size of the organism, the harder it is for them to cope with the strength of a cascade, said Ortega-Jimenez. The first attempt was made with eight small fruit flies. All 8 children were swept down by the waterfall and killed.
The next test was done with 7 house flies and flies. All of these flies have made it through the waterfall, but 2 fell after flying inside. Crane flies with long legs and slow flight are completely blocked.
Fruit flies and crane flies have been blocked by a waterfall and killed.
This shows that not any flying creature can survive the death of flowing water. The first challenge is that small insects have to overcome the surface tension of the water, Ortega-Jiménez said.
If it was too small and too weak, flying into the water would be like hitting a rubber wall. The animal will bounce back and shoot out.
The second challenge is that if they are not heavy enough, they will have to fly fast enough to have the momentum to overcome the downward force of the water. For example, scientists calculate that house flies must fly at 1.6 m / s to cross the falls. Otherwise, they will fall because a single drop of water is heavier than a fly’s body to hold it down.
The new study published in the Royal Society’s Open Science journal is an interesting one in the field of biology. Ortega-Jiménez says his team will use drones to hunt for similar moments in nature.
The natural waterfalls are definitely more ferocious and deadly than a lab waterfall. Therefore, the footage of real-life flying birds will be even more impressive.
Refer Science, Sciencealert