Digestion System

Flight requires a great deal of power. For this reason birds have the largest muscle-tissue/body-mass ratio of all creatures. Their metabolism is also in tune with high levels of muscle power. On average, a creature's metabolism doubles as the body temperature increases by 50°F (10°C). The sparrow's 108°F (42°C) body temperature and a fieldfare's 109.4°F (43.5°C)body temperature indicate how quickly their metabolism functions. Such a high body temperature, which would kill a land creature, is vitally important for a bird's survival by increasing energy consumption and, therefore, power.

Due to their need for a lot of energy, birds also have a body that digests the food they eat in an optimum fashion. Birds' digestive systems enable them to make the best use of the food they eat. For example, a baby stork puts on 2.2 lbs (1 kg) body mass for every 6.6 lbs (3 kg) food. In mammals with similar food choices, this ratio is about 2.2 lbs (1 kg) to 22 lbs. (10 kg). The circulatory system of birds has also been created in harmony with their high energy requirements. While a human's heart beats 78 times a minute, this rate is 460 for a sparrow and 615 for a humming bird. Similarly, blood circulation in birds is very fast. The oxygen that supplies all of these fast working systems is provided by special avian lungs.

The sparrow's heart beats 460 times per minute. Its body temperature is 108°F (42°C). Such a high body temperature, which would mean certain death for a land creature, is vitally important for a bird's survival. The high level of energy birds require for flight is generated by this rapid metabolism.

Birds also use their energy very efficiently. They demonstrate significantly higher efficiency in energy consumption than do mammals. For instance, a migrating swallow burns four kilocalories per mile (2.5 per kilometre) whereas a small mammal would burn 41 kilocalories.

Mutation cannot explain the differences between birds and mammals. Even if we assume one of these features to occur through random mutation, which is not a possibility, a single feature by itself does not make any sense. The formation of a high energy-producing metabolism has no meaning without specialised avian lungs.

A swallow

Moreover, this would cause the animal to choke from insufficient oxygen intake. If the respiratory system were to mutate before the other systems then the creature would inhale more oxygen than it needs, and would be harmed just the same. Another impossibility relates to the skeletal structure: even if the bird somehow obtained the avian lungs and metabolic adaptations it still could not fly. No matter how powerful, no land creature can take off from the ground due to its heavy and relatively segmented skeletal structure. The formation of wings also requires a distinct and flawless "design".

All of these facts take us to one result: it is simply impossible to explain the origin of birds through accidental growth or a theory of evolution. Thousands of different species of birds have been created with all their current
physical features in "a moment". In other words, God has created them individually.

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