Class Aves – Classification, Examples, & its Characteristics

Aves is an animal class that mostly includes all birds and their extinct ancestors. They are the endothermic vertebrates that fall under the phylum Chordata. The vertebrates that fall under the Aves class, have certain features like toothless jaws and they lay eggs with hard cells, etc.

The Aves class can be divided further into two major categories. The Archaeornithes are a set of extinct groups of Aves that had a beak with teeth and a long lizard-like tail. On the other side, Neornithes groups do not contain any teeth in their beaks and have short tails. In this article, we will discuss the Aves class, key characteristics, origin, and major classifications in detail.

Aves Definition

Aves are warm-blooded vertebrates that lay eggs and have specialized forelimbs to fly. They are bipedal whose endoskeleton is fully ossified and long bones pneumatic in nature.

What are Aves?

Aves are terrestrial animals that can fly. They have a lightweight string skeleton that helps them to protect their internal organs as well as provides support to fly a long way. Aves have a spindle-shaped body which is helpful for them to change direction while they are flying. This type of body structure reduces air resistance at the fly time.

They are visually attractive because of their colorful feathers with a unique pattern. The aves class contains around 9000 species that show courtship, parental care, nest building, and most importantly territorial behavior. Aves are the first vertebrates who have warm blood in their body.

Characteristics of Aves

Here are some key features and characteristics of the Aves class:

Feathers

• Feathers are the most recognizable feature of the Aves class.
• Feathers allow them to fly and keep them warm and insulated.
• There are so many varieties of feathers including down feathers, contour feathers, and flying feathers.

Wings

• Aves have specialized forelimbs to fly.
• Wings help them to lift their whole body and also contribute to maintaining flight.

Flight

• It is one of the most amazing abilities that the Aves class has adopted to fly.
• This ability helps them to create lift and maintain the flight constantly.
• With this adaption, their skeleton structure became changed over time.

Skeletal Adaptations

• Aves have more lightweight bones which is a unique skeleton structure. This adaptation was necessary to reduce the overall body to fly.
• Aves’s skull is lightweight. The beak is prominent and depends on the bird’s diet.
• The vertebral part of the Aves backbone is fused that provides the stability in an efficient flight.
• Many of the bones of the Aves are pneumatic. The air sacs are present in these bones and more efficient in exchanging gases.

Bipedal

• Aves are bipedal. They use both of the feet when they walk.
• This bipedial nature saves their energy and helps them to perch on branches more easily.

Warm-Blooded

• Aves are the first warm-blooded vertebrates.
• They can survive and keep their body temperature stable in the extreme conditions.
• They can take air during respiration in a wide range of habitats.

Beaks and Bills

• Beaks and Bills of the Aves are the result of anatomical adaptation.
• This adaption happened to grasp and swallow foods.
• Based on the species, the size and form of the beaks can be changed for Aves.

Alimentary Canal

• The Aves have a modified digestive system.
• It helps them to break and soften the food particles.
• There are so many Avas species that do not have the gallbladder.

Four-chambered Heart

• Aves have four-chambered heart.
• Their lungs are elastic and spongy.
• Their blood cells are oval-shaped, nucleated, and biconvex.

Endothermy

• Aves are able to keep their body temparature stable due to high metabolic rate.
• It helps to allow them to produce heat and Endothermy is the phenomenon.

Lay Eggs

• Aves are oviparous in nature as the fertilization process occurs in their body itself.
• Female produce eggs with four embryonic membranes. The layers are the chorion, the amnion, the allantoin, and the yolk sac.

Excretory Organ

• Aves also have the kidneys. It is their urinary organ and their unrine is semisolid in nature.

Highly Developed Sight

• Aves have excellent eyesight with an underdeveloped smell sense.
• They have one pair obvious eye with the ear holes.

Vocalizations

• To establish territory, attract mates, and communicate with one another, birds take the help of vocalizations.
• It is another way to distinguish different species of Aves.

Sexual Dimorphism

• Aves are oviparous in natute.
• Different Aves species shows difference in their sexual nature.
• Female produce eggs with four embryonic membranes. The layers are the chorion, the amnion, the allantoin, and the yolk sac.

Biological Classification of Aves

Aves are terrestrial animals that can fly. The vertebrates that fall under the Aves class, have certain features like toothless jaws and they lay eggs with hard cells, etc. Here is the biological classification of Aves

Kingdom	Animalia
Phylum	Chordata
Subphylum	Vertebrata
Class	Aves
Subclasses	Paleognathae, Neognathae
Infraclasses	Palaeognathae (Ratites, Tinamous), Neognathae (Various orders)
Superorders	Paleognathae (Palaeognathiformes, Tinamiformes), Neognathae (Various orders)
Orders	Falconiformes, Passeriformes, Anseriformes, Columbiformes, Struthioniformes, etc.

Classification of Aves

The Aves class can be classified further into two groups. Here we are going to discuss about them as mentioned below:

The Archaeornithes or Ancient Birds

The Archaeornithes or the ancient birds are a set of extinct groups of Aves that had a beak with teeth and a long lizard-like tail. Here are some major facts about them:

• Archaeornithes belong to the creatures of the prehistoric avian group that lived in the Mesozoic Era.
• They had a beak with teeth and a long lizard-like tail which made them distinct from the modern birds.
• Their wing bones, such as the humerus, radius, and ulna played a major role in making them able to fly.

The Neornithes or Modern birds

The Neornithes or modern birds the groups do not contain any teeth in their beaks and have a short tail. Here are some major facts:

• Neornithes or modern birds have more lightweight bones which is a unique skeleton structure.
• The Neornithes or the modern birds’ skull is lightweight.
• Ribs are connected by the small bones.
• Cervical Vertebrae are present in the neck of the Neornithes Or Modern Birds and provide high flexibility to the bird’s neck to regulate the movement of the head.

Examples of Aves

Here are some example of Aves class vertebrates with their scientific names as mentioned below:

Name Of The Birds	Scientific Names Of Birds
Bald Eagle	Haliaeetus leucocephalus
Common Raven	Corvus corax
Ruby-throated Hummingbird	Archilochus colubris
Peregrine Falcon	Falco peregrinus
Great Horned Owl	Bubo virginianus
European Robin	Erithacus rubecula
Emperor Penguin	Aptenodytes forsteri
Atlantic Puffin	Fratercula arctica
Southern Cassowary	Casuarius casuarius
Victoria Crowned Pigeon	Goura victoria

Conclusion – Aves

Aves are terrestrial animals that can fly. The vertebrates that fall under the Aves class, have certain features like toothless jaws and they lay eggs with hard cells, etc. They have a spindle-shaped body which is helpful for them to change direction while they are flying. They are visually attractive because of their colorful feathers with a unique pattern. In this article, we have learned about the Aves class with their key characteristics, origin, and major classifications in detail.

FAQs on Aves

What Defines an Aves?

Aves is the bird class. All birds are all under the Aves class. Aves are the first vertebrates who have warm blood in their body.

What are the Five Examples of Aves?

Doves, pigeons, falcons, ducks, sparrow, flamingo are the five examples of Aves. Aves are terrestrial animals that can fly.

Why is it called Aves?

Birds are called members of the Aves class. Only birds comprise the species that are found in this class. They are bipedal whose endoskeleton is fully ossified and long bones pneumatic in nature.

How are Aves Bones Special?

Aves have a unique skeleton structure. Many of their bone are pneumatic in nature. The air sacs are present in these bones and more efficient in exchanging gasses.

Which Bones are Stronger in Aves?

The shoulder bones of the Aves are strong. It is helpful in flying. Aves breastbones are modified to hold flight muscles. Aves have a streamlined body that is able to reduce air resistance in the flying time.

How many Bones do Aves have?

There are around 25 different bone types present in a Aves. Aves skeleton is Pneumatic and fused in nature. They are very tender which is structurally strong to fly in a great altitude and pressure.

Why are Aves Bones Fused?

The fusion of bones makes the Aves skeleton both lightweight and sturdy. It helps them to protect their internal organs as well as provides support to fly a long way. Aves have a spindle-shaped body.