They never live on land except for a few bird species like the ostrich, rooster, duck, etc.
Most of the time, they live on trees, elevations or keep flying in the sky.
The birds’ family has less diversification of its members than any other group of animals.
There are approximately 9,000 living species of birds known around the world so far. And many ornithologists are involved in discovering birds and their characters.
Types of birds in detail
Scientific classification of birds is done by broad features in 6 ways, as mentioned below. Each type has a specific order of birds like
1. Arboreal birds
The word “arboreal” means living mostly on trees. This group of birds lives their life in or around the shrubs. Scientifically they are classified under the superorder Neognathae and into four different orders like
a) Order: Passeriformes
This includes almost half of the known species of birds.
They have specific characters like having feet suitable for perching, and the beak is modified for cutting.
Their food habits are of omnivorous type but are chiefly granivorous. Therefore, these birds eat mostly grains like cereals and pulses.
The house sparrow is a typical example of this order.
They show sexual dimorphism and build their own nest for breeding.
Breeding occurs almost throughout the year. The females lay eggs at a time, and the successive broods are raised.
b) Order: Piciformes (woodpeckers )
Birds like the woodpeckers, toucans, sap-suckers and their allies are included in this order.
The woodpeckers are widely distributed in the world.
These are small birds that are found in lightly wooded country, orchards, and groves.
Their beak is modified as a long snout, chisel-like, and makes a hole in the tree trunk.
Their tail is stiff-pointed, wedge-like and is pressed against the stem.
These are small groups of birds, unlike the Passeriformes.
They are light-weighted and dig into rotten wood for beetles, grubs, ants, and other insects.
They have a long protrusible tongue with strong and sharp hooks or barbs at its tip.
The woodpeckers’ foot has 4 toes, with 2 in the front and 2 behind, which are not reversible.
c) Order: Columbiformes (dove-forms )
This order comprises birds like doves and pigeons.
There are about 500 species of pigeons described.
Pigeons live freely in ledges, fissures, and holes of rocks, forts, and crumbling buildings.
They are timid animals, inoffensive and harmless by nature, making them the family’s gentlest birds.
Externally, the pigeons’ bodies can be clearly demarked into a head, neck, trunk, and tail.
The body of these birds is streamlined, fusiform, and boat-shaped for proper flight in the air.
Their breeding season lasts for a year, with a brief courtship and copulation between the male and female birds.
Pigeons lack copulatory organs. But, they transfer the gametes through cloacal apertures leading to internal fertilization.
Unlike other birds, these pigeons are least interested in building nests. Instead, they just lay their eggs on bare stone, open spaces, or a plank.
d) Order: Psittaciformes (parrot form)
This order of birds comprises parrots, parakeets, cockatoos, macaws, lovebirds, etc.
The parrot’s size is similar to that of a pigeon, with a slender body and a long pointed beak. The parrot has a lush green color as it is covered by brilliant grass-green plumage.
Its feet are adapted for grasping, holding, running, and even climbing.
Parrots or parakeets are specialized in terms that they are gregarious with their loud voices.
These are the birds that spend most of their time on the ground. They keep walking, running, sitting on the ground despite their ability to fly.
Hence, the name ‘terrestrial birds.’
This kind of birds includes the following orders:
a) Order: Galliformes (cock forms )
These birds are heavy-bodied animals that mostly feed on the ground. They possess excellent palatability and prefer a largely graminivorous diet.
Their legs are strong and adapted for running. They also have massive feet that help in scratching the ground.
Their wings are round, and the wing muscles are attached to the keel bone. This keel bone is an extension of the sternum.
When needed, they can take a short and powerful flight with these wings.
The cocks are the male birds and are also called rosters. They take care of their female birds and even their eggs.
The birds of this order are also known as gallinaceous birds.
Example: red jungle fowl, peafowl, quail, etc.
b) Order: Cuculiformes (cuckoo form)
This order includes all cuckoos and their allied forms. The bird is well known for its melodious voice.
The bird is about the size of a crow with similar color in appearance. The female cuckoo is brown with white spots over the body. The male cuckoo sings in a melodious voice during summers.
Cuckoo is a nest parasite, and they rely on other birds to hatch their eggs and grow their siblings.
The sexual dimorphism is conspicuous in cuckoo.
Other examples: koel, crow-pheasant, etc.
c) Order: Struthioniformes (ratites)
This includes those birds which cannot fly.
They are quite large in size compared to other birds with long and strong legs. (The exception is the kiwis which are small in size with smaller legs.)
They lack keeled sterna and have underdeveloped breast muscles. As a result, they have a lower metabolic rate than the other birds with the ability to fly.
The adults are herbivores, while the young ones are omnivores, i.e., they eat insects and plant material.
Their eggs have thick shells and they maintain communal nests with other birds. The young birds born out of eggs are well developed comparatively and have an ability to run and swim.
Examples of birds are the Ostriches, emus, rheas.
Swimming and diving birds
These kinds of birds reside in the aquatic medium and also dive into the water.
Some commute to land for spawning but return to the water for further development.
The orders included in this are:
a) Order: Anseriformes (goose form )
This order includes aquatic birds such as geese, swans, and ducks.
The birds are highly aquatic and can fly up to some meters above the ground surface.
They are large in size with a heavyweight. Their body compact with a long neck and has black bars on the head. Their foot is fully webbed to help capture the prey.
They graze on short grasses in nearby lakes.
Some of the members of this order can also filter their food.
Examples: wild duck or mallard, common teal, swan, mergansers, etc.
b) Order: Coraciiform (crow or raven forms )
The order includes the birds like the kingfishers and their related allies.
The kingfishers are carnivorous in nature as they capture the small fishes for food.
Long and compact bills characterize them.
Their legs are slender and long, with their toes fused.
The house crows are necessary nature scavengers.
These kinds of birds are omnivorous birds, i.e., they can eat anything from dead sewer rats to kitchen refuge, insects, fruits, grains, and eggs.
Examples: white-breasted kingfisher, pied kingfisher, great hornbill, hoopoe, etc.
Shorebirds or wading birds
These aquatic birds seldom swim or dive beneath the water to a greater extent. Therefore, these birds are also known as divers.
The orders are:
a) Order Charadriiformes (genus of plovers )
This group has diverse water frequenting shore birds characterized by long wading legs, webbed toes, and multi-probing beaks.
The birds of this form size range from 0.06 to 4.44 pounds.
They vary mainly in their body length, physical statures.
The birds of this order are distributed in all parts of the world.
Their wings are usually white or gray colored.
These species mainly feed on fishes, while some of them feed on mussels and oysters.
Examples: red wattled lapwing, pheasant-tailed jacana, gull, etc
b) Order Ciconiiformes (stork form)
The order includes the long-legged marshy wading birds. They have long snake-like necks. The bill is slender and is shaped like a javelin or pincer-like for piercing their aquatic prey.
The body is divisible into a long neck, a bulky body with large, broad wings.
They have long wings, and they walk in shallow water with their long legs.
Examples: Cattle egret, heron, spoonbill, stork, flamingo, etc.
c) Order Gruiformes (crane form)
The order includes crane-like wading birds with long legs and partially webbed feet.
They have long wings rounded at the edges.
Their bills are long and slender.
Gruiformes are known for their exclusive mating rituals.
They are widespread in distribution.
Example: common coot, bustard, sarus crane. Etc.
Birds of prey
Some birds only capture their prey. These birds are diurnal with sharp beaks.
The order is the following :
a) Order Falconiformes (falcon forms)
This order includes the diurnal birds. They have a sharp hooked beak and strongly curved claws for capturing the prey.
These order birds have strong necks with a strong bill that is hooked on the tips.
The skin of these birds is fleshy and soft.
They are strong flyers in the sky and are carnivorous in feeding habits.
The feet are adapted for perching with sharp talons on the edge of the feet.
Example: common pariah, Brahmin kite, sparrow hawk, etc.
b) Order Strigiformes (owl form)
This order has the owls, which are nocturnal birds. They are characterized by large heads, huge yellow frontal eyes, and powerful grasping feet feathered up to toes.
These kinds of birds are solitary in nature.
They are prey-typified birds with an upright stance of stature.
The bird has a broad head with binocular vision.
The birds also bear sharp talons on their feet.
The feathers are adapted for silent flying.
Example: brown fish owl, great horned owl, etc.
The birds are mostly on wings in the air. They have weak or vestigial perching feet. However, the wings are strong and are well modified for aerial flight.
The orders are:
a) Order micropodiformes (footless form)
The order includes the swifts and hummingbirds.
These kinds of birds are gregarious insect eaters.
Their wings are long and narrow to cut the fluid nature of the air. This facilitates rapid flying in the air.
They are the smallest birds among the class of aves.
The legs are placed at the end of the body.
Example: Indian swift, palm swift, etc.
b) Order caprimulgiormes (goat sucker )
The order includes the shy, nocturnal, insectivorous birds such as night hawks, whippoorwills, goatsuckers, .etc.
They are the parasites on the goats.
They have large heads with large wide-open eyes.
Fine bristles are present around the mouth.
They are generally insectivorous in nature.
They have cryptically colored plumages.
They are highly active during the dawn and dusk hours only.