Bat flips,described in ScienceDaily 16 November 2015 and PLoS Biology 2015 doi: 10.1371/journal.pbio.1002297. Bats fly through the air with their heads forward and wings outstretched, but when they are not flying they like to literally hang around in trees, caves, or any places that allow them to rest hanging from their feet. This means they have to be able to “land” upside down. No other flying animals do this.
To see how it is done, biologists and engineers from Brown University trained bats to land on a net attached to a ceiling and took high speed videos of them as they came into land. They then analysed bat movements to see what forces they were using to flip themselves head down and feet up. When the bats are coming into land they are flying quite slowly, so it is difficult for them to use aerodynamic forces to turn their bodies. However, bats have heavy wings in comparison to other flying animals, and the research team found the bats were using this extra weight to generate inertial forces that shifted their centre of gravity, in the same way human high board divers achieve flips and rolls before entering the water (hopefully hands and head, rather than belly, first).
The PLoS synopsis explains the sequence of movements involved: “As the bat neared the ceiling, it slowed the flapping of its wings. Then, in quick succession, it retracted its wings on an upstroke, extended them on the next downstroke and—at the moment of flipping over—pulled one wing towards its body. As the bat flipped, the retracted wing stayed near the ceiling while the head and extended wing hung toward the floor. At the same time, the bat reached for the ceiling with its feet. All this took only half a second”.
Kenny Breuer, an engineer at Brown University commented: “What this tells us is that in bats, with their heavy wings, it’s the inertial forces that are more important relative to aerodynamics. That’s a bit of a counterintuitive conclusion. Normally you’d think that an animal would not want to have such massive wings. But here, it turns out that the mass can be used to some benefit”.
This kind of weight shifting is also used by cats to ensure they land feet down after jumping or falling from a height.
Editorial Comment: As one pilot said to me as I sat in a cockpit beside him: ‘There is more to flying than just being able to take off and stay in the air. Eventually you have to land, which can be the most hazardous part of flying!” That’s when I handed the controls back.
Time to admit that if a flying animal fails at Landing 101, it doesn’t get another chance to do better. This means slow gradual evolution is not going to convert a hypothetical evolving bat that can’t land upside down into one that can. Furthermore, even robust weighted wings are not enough. The animal has to have the sensory organs and nervous system to work out where it is in three dimensional space, and then be able to control the movements necessary for a back flip landing.
This study is confirmation that the bat origin theory that a mouse-like creature running on four legs changed into a winged creature that lands upside down, is one the evolutionists’ battiest ideas. Far more sensible to believe bats were created with take-off, flying and landing gear, and behaviour, all there from the beginning, and God the Creator richly deserves the credit. (Ref. chiroptera, aerodynamics, locomotion)
Evidence News vol. 15 No. 24
9 December 2015
Creation Research Australia