In the Beginning was Information

A3.4.4 The Flight of Migrating BirdsThe flight of birds is one of the 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,otherwise they could not fly. An aeroplane has to have a fairly highminimum airspeed to stay airborne, but birds can utilise the updraughtcaused by their wingstrokes to fly quite slowly. Their wings are carriersurfaces as well as propellers; the efficiency of the latter function is veryhigh, and cannot yet be attained by technological means. We now discusstwo of the numerous problems solved in the design of bird flight, namelythe 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 theenergy law, namely that a certain total amount of energy is required.Migrating birds have to carry enough energy in the form of fat to completetheir 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 the Creator provide forenough fuel without having “reserve tanks” or overnight “pit stops”? Thefirst aspect is to determine the most optimal speed. If a bird flies too slowly,it consumes too much fuel for propulsion. If it flies too fast, then moreenergy is required to overcome air friction. There is thus a certain optimumspeed for minimum fuel consumption. If the bird knew this specialspeed, it could fly the most economically. Depending on the aerodynamicsof its body and its wings, every bird has a specific optimal speed (it is 45km/h in the case of the Aztec seagull, for example; and 41.6 km/h for aparakeet). It is known that birds keep exactly to their optimum energysavingspeed when travelling. How do they know this? It is just one ofmany puzzles which ornithologists cannot solve.We now consider the energy problem in more detail in the case of thegolden plover (Pluvialis dominica fulva). These birds migrate from Alaskato spend the northern winter in Hawaii. They have to fly non-stop overthe ocean without resting, because there are no islands en route, neither dothey swim. During this 88 hour journey of more than 4,000 km (dependingon the point of departure), they beat their wings an enormous 250,000times without stopping at all. At the start their average weight G 0 is 200 g,70 g of which is padding (fat) which serves as fuel. It has been foundthat these birds consume 0.6 % of their weight per hour (fuel consumption241