Aves are a class of endothermic vertebrates, commonly known as birds. These animals fall under the phylum Chordata carrying specific features such as toothless jaws with beak, laying of eggs with a hard shell, etc.

Estimated 9000 species of Aves are present in the terrestrial animal kingdom. The capability of flying is the most dominant feature of this species. Their lightweight skeleton structure with strong but hollow bones helps them to fly.

Along with these salient features of Aves, the most visually attractive and remarkable characteristic is their colourful feather. A wide range of feathers with its unique pattern can be seen in the class of animals.

Aves are also called social animals as they can build nests, show territorial behaviour, and engage in courtship.

Example

Some of the Aves examples are Pigeon, Parrot, Sparrow, Owls, Penguins, Hummingbird, Crow, etc.

Aves Characteristics

Some general characteristics of Aves are the following-

One of the most visible class Aves characteristics is they are bipedal feathered animals. The fore-limbs of birds have developed into wings that help them to fly.
Their back-limbs have become legs that help them for swimming, walking, etc. Mostly, birds have four toes on their legs. However, two or three toes are also rarely visible.
Aves are homeothermic or warm-blooded creatures. Because of this, birds can keep a stable body temperature even when flying at high altitudes.
Birds don’t have any skin glands other than the uropygial gland or oil gland. This gland is situated near the tail.
Their jaws are transformed into beaks and they don't have any teeth. With the help of a beak, birds can feed in different ways like tearing flesh, crushing seeds, sipping nectar, etc.
Additional chambers called gizzard and crop are found in their alimentary canal. The crop chamber helps to soften the stored food, whereas the gizzard crushes the food. Few seed-eating birds like pigeons lack gall bladder in their system.
Lungs act as the primary respiratory organ in birds. Their lungs are inelastic and spongy. Lungs have air sacs to supplement respiration.
In birds, an organ called syrinx helps to produce voice.
Birds have a four-chambered heart and a reduced renal portal system. Also, their cardio-vascular system lacks sinus venosus.
The kidneys in birds are metanephric that help to filter the nitrogenous fluid waste via the ureters, into the cloaca. Their renal system lacks a urinary bladder.
Aves have a more developed brain then reptiles. Their brain consists of the cerebrum, cerebellum, and large optic lobes. Furthermore, 24 cranial nerves are present in their nervous system.
Birds have highly developed sight, but their smelling sense is poor. They have eyes and visible ear openings. Their ears are divided into three parts – internal, middle, and external.
Their endoskeleton is bony, and the bones are hollow. For this reason, the bones in birds are lighter than most animals. The bones lack bone marrow. The skull consists of a single occipital condyle.
The female birds have one ovary on the left side of the body and one oviduct. However, non-functional right ovaries and oviducts can be found in some cases.
Sexual dimorphism can be found in Aves, and they are oviparous. Bird eggs consist of four embryonic membranes – yolk, allantois, amnion, chorion.
Some other class Aves facts – they are spindle-shaped, and their shape helps to reduce the wind resistance while flying. Also, their feather passes the air to minimise air friction.
The fight muscles of Aves are highly developed.

Classification of Aves

Aves can be categorised into two classes. Here is the Aves classification up to order-

Archaeornithes

This class of Aves is extinct. Their beaked jaws had teeth and the tail was long like a lizard.

Example - Archaeopteryx

Neornithes

This class of Aves is both extant and extinct. They have toothless beaked-jaws and a short tail.

Example: Duck, Penguin, etc.

For further knowledge on Aves characteristics, go through the course materials available on our website. You can also install Vedantu’s app to join live classes and to download study materials on the go.

Characteristics of Aves - At A Glance

The common characteristics of all members of Class Aves are warm-blood, forelimbs modified into wings, well-developed flight muscles that help during the flight, their hind limbs are adapted for walking, hopping, perching, grasping, wading and swimming, epidermal scales on their legs, endoskeleton is bony with long hollow bones filled with air cavities (known as pneumatic bones), spindle-shaped body minimizes resistance of the wind, feathers help in preventing heat loss and reduce air friction by providing passage to the air, have no skin gland except the oil gland, lower and upper jaws are modified into a beak, have no teeth and sharp eyesight, the alimentary canal has a crop and a gizzard, pigeons and other seed-eating birds lack gall bladder, have spongy and elastic lungs for respiration, a special vocal organ called syrinx is present at the base of trachea, the heart is four-chambered, RBCs are oval, nucleated and biconvex, 12 pairs of cranial nerves are present, have a single ovary and oviduct on the left side, are oviparous and exhibit sexual dimorphism.

Want to read offline? download full PDF here

Download full PDF

Is this page helpful?

FAQs on Aves and Its Characteristics

1. What kingdom do birds belong to?

The classification of birds or the taxonomy refers to categorising the birds according to their physiological similarities and their general make-up. The first division in the classification system is the kingdom and the birds are placed in the kingdom Animalia. The next level is the phylum and the birds are placed in phylum Chordata, that is, the group of animals that have a backbone. Birds belong to the phylum Chordata of the kingdom Animalia. After kingdom and phylum, taxonomy divides into class and the birds are placed inside the class Aves.

2. What is the class name for birds?

Aves is the class name of birds. It’s clade is Ornithurine. Aves is a part of phylum Chordata of the animal kingdom and contains approximately 9000 species which have one thing in common and that is, they are all adapted to fly. The species placed in class Aves show parental care, courtship, territorial behaviour, and nest building. The class Aves is further divided into Archaeornithes (this class is now extinct because it contained birds with long lizard-like tails and toothed beaks) and Neornithes (this class includes birds that contain a short tail and no teeth).

3. What are some characteristics of Aves?

Some important Aves characteristics are – Aves have a beaked jaw with no tooth, most members of this species can fly, lay eggs, and have colourful feathers. Other common characteristics of Aves include warm-blooded animals, the presence of 12 pairs of cranial nerves, absence of teeth, sharp eyesight, four-chambered heart, oval, nucleated and biconvex RBCs, absence of any skin glands except oil glands, forelimbs modified into wings, well-adapted hindlimbs, jaws modified into a beak, and presence of epidermal scales on their legs.

4. What is the importance of birds to mankind?

The birds are not just only one of the living creatures of the world but they are also extremely useful to mankind. Some of the purposes that Aves fulfil are:

Birds and their eggs have been a source of food for humans since time immemorial.

Guinea fowl is an African bird that makes a lot of noise in an alarming situation, therefore, they were used in ancient times as an alarm to warn the approach of intruders.

Pigeons have also been trained to carry messages during wartime and ever since after that.

The hunting of birds has now become a sport of modern times.

Feathers of birds are used for decoration purposes like headpieces of indigenous people.

Feathers are also used for the manufacturing of ropes, mattresses, quilts, and pillows.

Large feathers are used in fans.

Ostriches are used for racing

Large quills have been used for writing.

Feathers are also used as arrows and fishing lures.

Birds like parrots, canary, finches, and budgerigar are also kept as pets at some places.

Many birds are also a source of recreation for millions of people.

Birds like guano are also used as fertiliser for crops.

5. What are the problems caused by the members of Aves?

The members of class Aves, that is, birds, are very useful to human beings but can even lead to some adverse effects. The birds which cause adverse effects to humans are pigeons, house sparrows, starlings, gulls, and Indian myna. These adverse effects of birds are:

Birds foul parked vehicles. The fouling of birds also leads to financial loss by spoiling the raw materials and finished goods.

Large birds can dislodge roof tiles.

Birds can spread many diseases caused by bacteria, viruses, and parasites with microorganisms like Salmonella, E. coli, and Histoplasma.

Birds also spread insects and parasites like ticks, fleas, lice, fur beetles, carpet beetles, cloth moths, and mites.

Nests block the drain pipes and gutter which causes flooding on the roof that leads to rotten timbers, internal leaks, damaged plaster, and metal corrosion. These sites then become breeding sites for biting and flying insects.