Birds are a group of vertebrates of warm-blooded animals, with wings and feathers, and are able to fly except for a few species that use their wings to balance while walking and running, or swimming in water like a penguin, and ostrich is the largest species of bird, and hummingbird is the smallest.
Birds can also be defined in a scientific way as a group of hot-blooded animals that are closer to reptiles than to mammals, and they have a heart consisting of four rooms: atria and ventricles, and there are four sides; two of them are turned into two wings, and lay eggs with a solid shell Birds have a strong eyesight, which represents their basic sense of learning about their surrounding environment, and their sense of smell is rudimentary, but its hearing is somewhat limited.
Classification of birds in biology:
Most biologists relied on a taxonomic stand on the shape and appearance of birds to divide them into types, including dependence on the properties of feathers, such as: different types and bodies, and also relied on the shape of the beak and feet, and their function in obtaining food, in addition to The behavior of the bird, the body of the skull, and the presence of certain muscles in the thigh region, or the lack thereof, but now the evolution of the study of DNA and its complex sequences has made it possible to develop new and developed ways and means to study the evolutionary and genetic relations between the species of birds, and divide them into Building groups on them.
Types of birds and their names:
The number of species known in the world currently reaches about ten thousand species, all of which are distinguished by feathers that cover mainly adapted bodies with their ability to fly,  and bird biologists classify several groups based on their functions and internal anatomy, and they are classified as The main is divided into two parts: the ancient jaws (the scientific name: Palaeognathae), and the jaws’ modernities (the scientific name: Neognathae). Below is a list of the main subgroups of them – the ranks – that scholars now agree on for the birds:
- Above the rank of ancient jaws: It consists of a small number of species and contains all flat areas (Ratites) and tinamous, and is divided into 5 classes as follows:
- Rank of Developments: (TINAMIFORMES), it consists of 47 species and is capable of flying.
- RHEIFORMES, consisting of two types unable to fly, is found in South America.
- Ostrich rank: (STRUTHIONIFORMES), is one species, and is the largest bird species, and it is very fast although it is not able to fly, as it is located in Africa.
- The rank of chimpanzees: (CASUARIIFORMES), consisting of 4 types that are not able to fly, and are found in Australia, and the types of sheep and emo.
- The rank of Kiwi: (Apterygiformes), consisting of 3 species found in New Zealand, and considered the largest eggs of all birds relative to their size, and they are unable to fly.
2. Above the rank of modern jaw: it includes all modern birds, and the composition of their bones differs from the old jaw, and is divided into approximately 24 ranks as follows:
- The rank of chickens: (Galliformes), it contains 258 species, and it is found in all countries, and among its types, chicken and Ethiopian.
- The rank of the oozes: (Anseriformes), they are found all over the world, and there are 161 of them, as most of them live in water, and among them are geese, swans and ducks.
- The rank of the penguins: (Sphenisciformes), contains 17 species, and most of them are found in the southern ocean, and they cannot fly and can swim in the water, and their body adapts to severe cold through thick feathers, and a thick fat layer.
- The rank of divers: (Gaviiformes), contains 5 species, and is located in the Antarctic, and can dive and swim in the water, as it feeds on fish.
- The rank of prokaryotes (Procellariiformes), contains about 115 species of birds, and is present in all oceans, the class of diving: (Podicipediformes), contains 21 species, and is found all over the world, and you can dive and swim underwater using the feet to search for food.
- The rank of pink flamingos: (Phenicopteriformes), contains 5 types, and is found in tropical and sub-tropical regions all over the world except for Australia, and is usually found in saline and shallow lakes.
- Stork Order: (Ciconiiformes), contains approximately 120 species, and is found all over the world.
- Pelecaniformes, which contain approximately 67 species, are found in all oceans and temperate tropical regions.
- The order of prey: (Accipitriformes), contains approximately 240 species and is found in all countries of the world.
- Falconiformes, which contain approximately 64 species, are found in all countries of the world, and feed on meat.
- The rank of crocs: (Gruiformes), contains approximately 210 species and is found in all countries of the world, and includes wild, water and semi-aquatic species.
- The rank of Charadriiformes: It contains more than 300 species and is present all over the world, most of which are waterbirds.
- Pteroclidiformes, they contain 16 species, are found in the countries of the ancient world, and generally live on dry lands.
- The order of erythema: (Columbiformes), contains more than 300 species and is present all over the world, and it feeds on seeds and fruit.
- The order of parrots: (Psittaciformes), contains approximately 358 species, and it is found in tropical regions, and its species abound in Australia.
- The rank of opisthocomiformes, which is one species found in South America.
- Musophagiformes, consisting of 23 species, are found in Africa.
- Cuculiformes, consisting of 143 species, are found all over the world.
- The rank of owls: (Strigiformes), it consists of 178 species, and is found all over the world.
- The order of the Sebadians: (Caprimulgiformes), consisting of 113 species, and is found all over the world in the tropics.
- The Order of the Celestial: (Apodiformes), contains more than 400 species and is found all over the world.
- Coliiformes, which contains 6 types, are found in Africa.
- Trogoniformes, 39 species, are found all over the world in tropical regions except Australia.
- Leptosomatiformes, consisting of one species, are found in Madagascar.
- The Order of Illuminations: (Coraciiformes), consisting of approximately 156 species, and is found all over the world.
- Piciformes, consisting of approximately 410 species, are found all over the world, especially in the tropics.
- Bucerotiformes, consisting of approximately 62 species, are found in Africa, Asia and Madagascar.
- Passeriformes, they contain about 5700 species, which is equivalent to half of the species of birds, as they are found all over the world.