Some characteristics of modern birds are feathers, beak, egg-laying, high metabolic rate, four-chambered heart, light weight but strong skeleton. Wings which are actually evolved forelimbs help the birds in their flight. The unique digestive and respiratory system of the birds help them fly to great heights. Some birds cannot fly, penguin is one such species.
Certain birds are known to be highly intelligent like parrots and corvids, while some are capable of transmitting knowledge across generations. The way certain birds create very intricately woven and safe nests to preserve their eggs indicates the use of manufacturing skills they possess. Birds are very closely connected with the environment. They are known to be intuitive about weather conditions that may prevail in the region much ahead than humans can predict it with any forecast methods and instruments. Their monitoring and careful examination is also used as an indicator of the weather conditions. Presence of peacock symbolizes rain and good weather while owls, bats and vultures are said to indicate a bad, unpleasant weather in an area.
Certain birds are kept near coal mines for the prediction of mine explosion, as birds are sensitive to the release of high levels of carbon monoxide beyond permitted limits and begin to die. Birds are social. Most communication happens through sounds that they make or singing that they do. They live in flocks, hunt, breed cooperatively and participate in social behaviors. Birds incubate the eggs they lay and take longer care of the hatched birds as parents. Birds have the freedom to move anywhere they want and care for no boundaries of political or cultural divide except the suitability of the environment.
Many birds have been extinct due to hunting, poaching, disturbed ecological balance and many more are under constant threat of extinction. Even birds living in water like swans, ducks etc. have seen a drastic fall in numbers because of the pollutants like poisonous chemicals and pesticides being constantly added to the water bodies. Also birds living close to the river banks consume polluted water and die. As birds are vital to the balance of this ecosystem, we must take adequate steps to preserve them providing them safe and clean habitat for survival.