Pigeon - Circulatory system and Venous system
The heart is four chambered, with two auricles and two ventricles. There is complete separation of the oxygenated and non-oxygenated blood. Birds have two distinct circulations as arterial and venous systems.
From the right ventricle arises the pulmonary artery carrying deoxy-genated blood to the lungs for purification. An aorta arises from the left ven-tricle (right systemic). It carries oxygenated blood to various regions of the body through several arteries.
The deoxygenated blood from various regions of the body are col-lected by several veins. Finally these veins take the blood to the right auricle through the two precaval and a single postcaval veins.
Sub phylum - Vertebrata
Class - Aves
Order - Columbiformes
Type - Columba livia
Birds are easily recongnised group of vertebrates. In birds every part of the body is modified to suit their aerial mode of life. Birds possess feathers, beak and feet modified in relation to their aerial life.
The Pigeons are flying birds(carinate). They are known both as wild and domesticated forms. The Pigeons are seen both in tropical and temperate zones. About 10 species of Pigeons are found in India. The pigeons fly in flocks and roost together. The domestic pigeons have many varieties, namely panter, fantail and tumblers. They differ in size, colouration and feather ar-rangement. All of them are, however, descendants of the rock pigeon-columba livia.