The birds have an efficient circulation, a high rate of metabolism and a high and constant temperature. The birds and mammals are the only vertebrates that have a complete separation of the respiratory and systemic circulations, making possible a high arteriolar pressure, which allows materials to reach the tissues rapidly. The circulatory system of pigeon includes heart, arteries, veins, the [...]
The digestive system of pigeon is well developed and includes an alimentary canal and the digestive glands. Alimentary Canal: The alimentary canal of pigeon (Fig. 26.28) is long, tubular and coiled. It comprises mouth, buccal cavity, pharynx, oesophagus, stomach, small intestine and large intestine which opens to the exterior by cloacal aperture. All the segments of alimentary canal fall into [...]
The pigeon, like other vertebrates, has receptors or sense organs for touch, smell, taste, sight and hearing which are stimulated by the environment. These sense organs are termed external receptors or exteroceptors. The pigeon possesses following exteroceptors: 1. Tactile Organs: These are poorly developed in birds due to feathery covering of the body. Tactile organs of pigeon remain confined to [...]