Page 54 - Design in Nature

52 DESIGN IN NATURE

words, while the weight of fuel has to be at a minimum, the energy output
from it has to be at a maximum. All of these problems have been solved for
birds.
The first step is to determine the optimum speed for flight. If the bird is
to fly very slowly, then a lot of energy has to be spent to remain aloft in the
air. If the bird is to fly very fast, then fuel will be spent in overcoming air
resistance. It is therefore obvious that an ideal speed has to be maintained in
order to spend the least amount of fuel. Depending on the aerodynamic
structure of the skeleton and wings, a different speed is ideal for each kind
of bird.
Let us examine this energy problem as it relates to the Pacific golden
plover (Pluvialis dominica fulva): this bird migrates from Alaska to Hawaii
to spend its winters there. There are no islands on its route. Therefore, it has
no possibility for rest. The flight is 2500 miles (4000 km) from start to finish

and this roughly means 250,000 wing beats without break. The trip takes
more than 88 hours.
The bird weighs 7 ounces (200g) at the start of the journey, 2,5 ounces
(70g) of which is fat to be used as fuel. However, scientists, after calculating
the amount of energy the bird needs for an hour of flight, determined that
the bird needed 3 ounces (82g) of fuel for this flight. That is, there is a
shortage of 0.4 ounce (12g) of fuel and the bird would have to run out of

energy hundreds of miles before reaching Hawaii.
In spite of these calculations, the golden rain birds unfailingly reach
Hawaii every year. What could the secret of these creatures be?
The Creator of these birds, Allah, inspires them with a method to make
their flight easy and efficient. The birds do not fly haphazardly but in a flock.
They follow a certain order and form a "V" shape in the air. This V formation
reduces the air resistance that they encounter. This flight formation is so
efficient that they save about 23% of their energy. This is how they still have
0.2 ounces (6-7g) of fat when they land. The extra fat is not a miscalculation

but a cushion to be used in case of encountering reverse air currents. 21
This extraordinary situation brings the following questions to mind: