In the Beginning was Information
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A3.4.4 The Flight of Migrating BirdsThe flight of birds is one of <strong>the</strong> most fascinating kinds of propulsion seenin creation. It involves numerous solutions which cannot be imitated technologically[D2, R3, and S2]. Aerodynamically, birds’ wings are highlyspecialised and optimised structures. Their curvature is especially important,o<strong>the</strong>rwise <strong>the</strong>y could not fly. An aeroplane has to have a fairly highminimum airspeed to stay airborne, but birds can utilise <strong>the</strong> updraughtcaused by <strong>the</strong>ir wingstrokes to fly quite slowly. Their wings are carriersurfaces as well as propellers; <strong>the</strong> efficiency of <strong>the</strong> latter function is veryhigh, and cannot yet be attained by technological means. We now discusstwo of <strong>the</strong> numerous problems solved in <strong>the</strong> design of bird flight, namely<strong>the</strong> matters of precise energy calculations, and exact navigation.A3.4.4.1 The Flight of Migrating Birds: An Accurate EnergyCalculationEvery physical, technological and biological process strictly obeys <strong>the</strong>energy law, namely that a certain total amount of energy is required.Migrating birds have to carry enough energy in <strong>the</strong> form of fat to complete<strong>the</strong>ir journey. But birds’ bodies have to be as light as possible, sounnecessary weight should be strictly avoided. It is also necessary thatfuel consumption should be optimal. How did <strong>the</strong> Creator provide forenough fuel without having “reserve tanks” or overnight “pit stops”? Thefirst aspect is to determine <strong>the</strong> most optimal speed. If a bird flies too slowly,it consumes too much fuel for propulsion. If it flies too fast, <strong>the</strong>n moreenergy is required to overcome air friction. There is thus a certain optimumspeed for minimum fuel consumption. If <strong>the</strong> bird knew this specialspeed, it could fly <strong>the</strong> most economically. Depending on <strong>the</strong> aerodynamicsof its body and its wings, every bird has a specific optimal speed (it is 45km/h in <strong>the</strong> case of <strong>the</strong> Aztec seagull, for example; and 41.6 km/h for aparakeet). It is known that birds keep exactly to <strong>the</strong>ir optimum energysavingspeed when travelling. How do <strong>the</strong>y know this? It is just one ofmany puzzles which ornithologists cannot solve.We now consider <strong>the</strong> energy problem in more detail in <strong>the</strong> case of <strong>the</strong>golden plover (Pluvialis dominica fulva). These birds migrate from Alaskato spend <strong>the</strong> nor<strong>the</strong>rn winter in Hawaii. They have to fly non-stop over<strong>the</strong> ocean without resting, because <strong>the</strong>re are no islands en route, nei<strong>the</strong>r do<strong>the</strong>y swim. During this 88 hour journey of more than 4,000 km (dependingon <strong>the</strong> point of departure), <strong>the</strong>y beat <strong>the</strong>ir wings an enormous 250,000times without stopping at all. At <strong>the</strong> start <strong>the</strong>ir average weight G 0 is 200 g,70 g of which is padding (fat) which serves as fuel. It has been foundthat <strong>the</strong>se birds consume 0.6 % of <strong>the</strong>ir weight per hour (fuel consumption241