Though most birds can fly and mostly live high up, they come back to ground at least for food and prey, if not for other purposes. Large or small, all of them have a very well developed lungs. They have adapted their features well so as to help keep their bodies warm.
When on ground, some prefer the grassy land, some high rocks. Some are just ga ga over the wild flowery woodlands. Some prefer preying in fresh water, some like to be busy by the seashore. Depending on the preference of hunting and hatching the birds thrive and throng the earth in myriad of size, shapes, color and sound.
The high flyers
include the mountain birds who are equipped to stand cold, wind and fierce rays from the sun. The small ones rarely risk a flight. In summer, the sparrow-like accentors of Europe and Asia merely hop about in search of insects on the green patches and in the rocky crevices. High up in the Andes the Patagonian earth creeper is a bird no bigger than a flinch. It nests in a windproof snuggery which it builds by digging up a meter long tunnel to ward off the cold and gale. The Himalayan variety actually nests above 5000 meters (17000 ft). But as winter closes in, they move downhill to safer and warmer land.
Wall creepers reach even higher levels as they probe cliffs for insects, clinging on with toes and tail.
The partridge like rock ptarmigan turns white in winter to camouflage against the snow.
The bigger mountain birds
are strong enough to cope with violent winds. Some fly or soar among the very high peaks. Mountaineers have even seen choughs flying even near the summit of some highest mountain tops. These are a type of crow with yellow bills, find worms and insects among the rocks. Winds continuously shower the upper slopes with dead and dying insects whisked up from the lowlands. Million end up high on the snowfields which act as a natural freezer. So the mountain birds can have them in plenty.
However, the flying giants need bigger morsels. Mountain eagles with the sharpest eyesight swoop on small mammals and birds from a long distance below. Vultures scavenge food from any corpse, also with a gifted vision to spot food. Andean condors are the largest of all soaring vultures. Both groups can soar for hours on air rushing up the slopes. Their mighty wings are specially designed to do so. Both nest and lay eggs on cliff ledges, safe from other mountain predators.
Thousands of bird variety thrive in the cold icy polar regions of Arctic lands. But because of tremendous cold most migratory in nature and are summervisitors. Long daylight hours for feeding, and plenty of insects make the tundra a good place for lots of song birds such as wheatears, warbles and sand martins.
Among the predators there is snowy owls which depend heavily on mouse-like lemmings. But when lemmings go scarce many owls migrate or starve.
The forest of the island continent Australia is inhabited by colorful birds. Like lyre-birds which skulk among thick underbrush, where males display their long tails shaped like the ancient musical instrument.
Yet another variety is kookaburra, belonging to the kingfisher family. It hunts insects and reptiles.
In the rain forests of Amazons is inhabited by scarlet macaw, of parrot family. Though they do not have the crest like the Cockatoos, but they display brighter variety of colors.
The toucans are of the fruit eating birds with huge, pointed, brightly colored beaks.
The tiny multicolored hummingbird that sips nectar from the flowers can hover mid-air with the beaks planted inside the flower. It does so by flapping its wings at a tremendous speed. The predator bird in the Amazon include the harpy eagle which rests and nests on the treetops with a keen eye for the prey, mostly monkeys.
But most variety in color and species is seen among the tropical birds. Plenty of thick trees and the creepers provide homes for birds along with snakes and monkeys.
The broadleaved branches and treetops make the perfect nesting sites for a wealth of gaily colored birds.
The brilliantly colored male birds like Wilson's bird of paradise, regent bowerbird and Count Raggi's bird of paradise deck the hot and humid forests of New Guinea and north east Australia. The males have a plumage and display to help the females of their species to identify them among the branches.
In the tropical forests of Africa and South East Asia there are fruit eating birds feeding among the canopy. This include hornbills, parrots. And there is also tiny gaily colored sunbird of the hummingbird family.
The broadleaved woodlands of the North is the habitat for a lesser variety of birds than the tropical forests. The small ones include the song birds like thrush, nightingale and the common variety like woodpecker. Blue jays live in the woodlands of the eastern United States and Canada. They eat nuts, acorns and small seeds. In spring they steal eggs and chicks from the nests of other woodland birds. Hummingbirds also inhabits North America.
Farther up the coniferous forests in the north offers short summer and long cold winter. While most are migratory visitors from the colder tundra and Arctic land, the typical inhabitant of these forests include the tits, warblers, and the plant eating crossbills; along with the woodpeckers. Tilts and warblers hunt insects high up among the twigs ad leaves. As autumn draws warblers fly south. Swallows nest in Europe in the summer. To escape the winter cold they fly deep south to Africa. Other migratory birds include bobolink, a songbird. It breeds as far north as the Canadian forests. But it winters as far south as Argentina.
Again some from the polar region make these lesser cold forest their winter home. The hunter birds include the goshawk and the owl. Both are famous for the agility.
The grasslands of the prairies in North America is the habitat of quite a lesser variety of birds. While the prairie chicken belongs to the fowl family and the larger preying variety include the prairie falcon and the burrowing owl.
Meanwhile, the grasslands of African savannah houses no more a greater variety. The flightless ostrich, the largest bird on earth, hails from here. Each of its two antelope-like feet rests on long toes that help to lengthen the leg and give a long, swift stride.
The grasslands of steppe is replete with birds of prey like the huge taloned steppe harrier and the very large tawny eagles.
The low Australian grassland is also home to a sizeable variety of birds. And many of them are not found elsewhere in the world. Perching on the grassland trees there are flocks of budgerigars. The big-tailed crested cockatoosof parrot family also perch on the gum trees. Here, wedge-tailed eagles swoop on birds, rabbits the small marsupials. These beat all the eagles in the wing-span which extends 2 meters(6 1/2 ft).
Deserts offer a more hostile surroundings for the birds and animals to live in. Most desert birds must drink often to replace the water they lose. This forces them to live near the waterholes or rivers. But pools of water in deserts often tend to be salty. Ostriches are among the few birds that can drink salty water without coming to harm.
Most of the desert birds eat insects. Others are carnivorous - mostly reptiles. Still a handful eat seeds. Vultures and condors soar up into the cool air high above the hot sands or rocks. The Californian roadrunner kills and eats snakes. The Sonora white rumpled shrike builds a larder of lizards skewered on thorns. Small birds hide from the heat of the day in the shade. Small birds of this region include fowls, geese, ducks and grouses. The Gila woodpecker lives in the hollow of large cactus plants in the North America. The sand grouse may soak their breasts, then fly many kilometers to chicks that suck water from their feathers.
Peacocks are seen in the semi desert region of India. The male birds sport a crest and a long feathery tail of multiple shades of silvery blue, green and golden and yellow.They raise their tail like a fan to attract the female bird, peahen. Equipped with sharp bills they eat insects and small snakes. Their number has reduced much these days.
Water birds comprise majority of the migratory birds. Crustaceans in the many ponds make it suitable for these birds, particularly ducks, eiders, geese, terns and waders. These migratory birds are famous for taking long distance flight. These include the red throated pipit and water birds like red breasted goose and snow goose. But the champion long distance traveler is the Arctic tern which migrates half way around the world.
Compared to the Arctic birds in Antarctica lacks variety. Though migratory water birds do visit the cold summer seas belting the continent, they do not make it farther up to the frozen land where food is a real scarcity.
Best known of all the Antarctic birds are penguins. Though most of the variety live on the icy coasts of the Antarctic, some venture farther upward on the desolate islands of the Indian oceans. Apart from the flightless penguins, the sheathbill are the rather ugly southern relatives of gulls. These live by snapping up the dead penguin chicks and morsels dropped by penguin parents. The skua is the snatching variety, which live on by seizing untended eggs and chicks of penguins.
Among the others, the fragile looking snow petrel nests up to 320 km inland farther south than any other bird.
The flightless birds
The flightless variety in the South include the penguins. These flightless birds have wings which they use as flippers. They are more comfortable in water and swim superbly after fish and squids. On land they waddle awkwardly. They lay eggs on land. The smaller Adelie penguins trudge and slide across large distance to reach the breeding rookeries. Hardiest of all is the emperor penguin. It breeds on ice sheets. Males incubate the eggs between their feet and belly skin flaps. They also protect the eggs from the predators. The females fish for squids to feed the hatchlings.
Moving northward from the Antarctica lies the Australia and New Zealand. New Zealand houses most significant of all flightless variety. While giant moa, larger than ostrich have been wiped off by man long ago. Only the small variety like kiwi and takahe sustains. The small kiwis, laying larger-than-self eggs, have been made New Zealand's national bird. The takahe is a hen-sized bird with green blue eyes. It spends summer in marshy mountain valleys and during winters it hops lower down.
The vast Australian lowland houses a wealth of colorful birds. The large variety includes the Emus. The largest of all in this lowland. Strutting in the lowlands of Australia, they are, in fact, second only to the Ostrich, the African variety .
Fresh water variety:
These apart, all over the world fresh water birds show the greatest variety and countless in number. Almost all undisturbed lakes, ponds, pools and wetlands are busy with the noise and activities of water birds. Ranging from the familiar family of ducks and ducklings, and those conceited long necked swans and ganders, there are flamingos, pelican, cranes, herons, coots, great crested grebe, drakes, bitten, lily trotters and many more. Leave aside the gaily colored kingfisher and other birds that rests up above the ground on the branch, their diving or swooping platform.
Some keeps wading, some waits meditatively, some prefers to stand erect on just one leg like a watch tower, while some drops in water suddenly from nowhere. Some are hard swimmers, some just float idly. Some are too restless - taking dips, flapping on the wings, pacing up the swimming speed and then pacing down.
The darters of Asia, Africa and the Americas swim well underwater. These snaky necked birds can stab a fish with their long, spear-like bills.
Cormorants also dive for fishes. Brown pelicans plunge for prey but white pelicans often swim in flocks to trap fishes by driving them into the shallows.
Shovellers are ducks that sieve small creatures from the mud. Flamingos and spoonbills feed in a similar way. But the long legged herons are wading birds that hunt for fishes.
The dainty lily-trotters go in for insects and snails that live among the lilies.
But the water birds not only throng the freshwater area. Those preferring the salty seashores are also quite a few.
The common variety includes various seagulls, oystercatchers, the long billed curlews, the terns, gannets, kittiwakes, guillemots and puffins. Sea gulls may be different like the black headed gull, the all white gull, the grayish gulls. And the albatross is the largest of all the gulls.
Of all these shore birds some prefer sandy shores some the sea washed rocks. Obviously it is due to their food habits.
Well, all these represent just a cross section based on the broad classification of the habitats of birds the world over. There are also various commonly seen birds which live and play around us. Who hasn't been harassed by the little mischievous magpie? Or irritated by the quarreling sparrows, the harsh cawing of the crows? Partridges though not a frequenter around our locality, they are not rare. There are a few who have not seen kites and gulls circling high up in the sky. Again there are plenty chirping and twittering from the nearby trees, the backyard bushes and from among the wayside underbrush. Mostly beyond our busy eyes. A caring look will reveal them and be a source of real pleasure. While quite a few have been included, many more are possibly left. May be, they will be seen here in future.