With regard to flying vertebrates, birds are the largest class of animals. The presence of feathers on an object classifies it as a bird. Actually, the only class of animals with feathers is birds. While most birds are avian and all birds begin as eggs, these traits are also shared by other animal classes.
Birds are members of the class Aves and the phylum Chordata. The class of warm-blooded animals includes these avian winged creatures. The majority of birds are easily recognized by their beaks, wings, feathers, and the fact that they are hatched from eggs.
There are thought to be more than 18,000 different species of birds. Birds vary greatly in size; the enormous, flightless ostrich stands over 9 feet (2.75 meters) tall, while the tiny, exquisite hummingbird is only 2 inches (5 cm) long. Among all the animals, birds are among the most colorful and beautiful. Parrots, birds of paradise, ducks, wrens, finches, and peacocks, for instance, can have incredible shades of yellow, blue, red, green, and orange.
You might not consider certain bird species to be birds. The family Spheniscidae, which includes the birds commonly known as penguins, is one such species. Genera in this species live in South American and Southern Hemisphere nations. Despite their inability to fly and propensity for swimming, they belong to the bird family.
Certain people mistakenly believe that birds belong in the mammal category when it comes to their correct classification. Despite sharing a backbone and being warm-blooded, birds and mammals differ greatly from one another. The fact that birds lack teeth and have beaks is one of their differences. Furthermore, because they do not give birth to their young or breastfeed them, birds are not considered mammals.
Another significant source of food for humans is birds. For instance, compared to red meat like beef and pork, eggs are high in protein and many varieties of poultry are low in fat.
