Birds (Aves) : The Indian Roller (Coracias benghalensis)
Birds are a group of warm-blooded vertebrates constituting the class Aves, characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweight skeleton.
Their forelimbs are modified into wings.
They have well-developed flight muscles that help during the flight.
Their hind limbs are adapted for walking, hopping, perching, grasping, wading and swimming.
There are epidermal scales on their legs.
The endoskeleton is bony with long hollow bones filled with air cavities. known as pneumatic bones.
Their spindle-shaped body minimizes resistance of the wind.
The feathers help in preventing heat loss and reduce air friction by providing passage to the air.
There is no skin gland except the oil gland.
The lower and upper and jaws are modified into a beak.
They have no teeth.
They have sharp eyesight.
The alimentary canal has a crop and a gizzard. The crops help in softening food, and the gizzard helps in crushing the food.
Pigeons and other seed-eating birds lack a gall bladder.
They have spongy and elastic lungs for respiration.
The special vocal organ called syrinx is present at the base of trachea.
Their heart is four-chambered.
RBCs are oval, nucleated and biconvex.
12 pairs of cranial nerves are present.
They have a single ovary and oviduct on the left side
All the birds are oviparous and exhibit sexual dimorphism. The eggs have four embryonic membranes- amnion, chorion, allantois, and yolk sac.
The endoskeleton of birds is bony. The long bones are hollow with air cavities (pneumatic).
Feathers are an exoskeletal structure which is a characteristic feature of birds. The feathers can be useful for sexual attraction between the two sexes in birds for the process of sexual reproduction. The feathers also help in protection and maintaining the body temperature.
Birds reproduce by internal fertilization, during which the egg is fertilized inside the female. Like reptiles, birds have cloaca, or a single exit and entrance for sperm, eggs, and waste. The male brings his sperm to the female cloaca. The sperm fertilizes the egg. Then the hard-shelled egg develops within the female.
The digestive order is as follows: bill, mouth, tongue, pharynx, esophagus, crop, proventriculus, gizzard, small intestine, caeca, rectum, cloaca. shapes and are used for scooping, pecking, tearing and generally picking up the bird's food.
Birds, having a closed circulatory system, have a 4-chambered heart (2 atria & 2 ventricles), with complete separation of oxygenated and de-oxygenated blood. The right ventricle pumps blood to the lungs, while the left ventricle pumps blood to the rest of the body.
The name Roller is derived from the twists and turns the bird makes in flight. Breeding from March to June, it creates its nest in holes in the trunks of trees, which were originally made by boring insects or woodpeckers.
Scientific Classification of The Indian Roller
Kingdom:Animalia
Phylum: Chordata
Class: Aves
Order: Coraciiformes
Family: Coraciidae
Genus: Coracias
Species: C. benghalensis