^^ 안녕하세요.. THE FALL AND RISE OF THE BALD EAGLE For over two hundred years the bald eagle has been the symbol of America, with the likeness of this powerful bird found on our coins and on the Great Seal of the United States. Two hundred years ago, bald eagles were found throughout North America,  but by the 1970s there were very few left outside of Alaska. The only creatures that menace the bald eagle are human beings. Why are there so few these birds left? What are they like? The bald ealge is a large, powerful bird that is not really bald. It gets its name from its white-feathered head, which contrasts strongly with the rest of its brown-feathered body. When it flies, it looks strong, powerful, and as if it is a master of the air. Its keen vision, great talons, and large, strongly hooked beak equip the bald eagle to live by hunting. In its search for small animals and fish, which form the greater part of its diet, it will sometimes pounce on a small lamb or piglet. Because of this, ranchers and farmers waged war on bald eagles for hundred years, killing them in large numbers. In addition, hunters shot them in order to have them stuffed as trophies. In the 1950s it became apparent that there was a sharp drop in the number of bald eagles. The reason for this was soon discovered. The eagles' eggs were fragile and broke easily, killing the young chicken inside. The cause of the thin shells remained unknown for a number of years. Finally, the mystery was solved by a scientist named Rachel Carson. Rachel Carson was concerned about the use of pesticides, chemicals used to kill insects that damage crops. In 1962 she wrote a book called 'Silent Spring' that showed how some chemicals were harming the nation's wildlife. The book explained the cause of the thin eagle shells: it was DDT, a pesticide that had been in widespread use in the United States for over ten years. DDT had become concentrated in laked and streams. Once it was in the water, it poisoned fish. The DDT in the fish that the bald eagles ate caused the birds to lay eggs that had the thinner shells that broke so easily. Rachel Carson hoped that Congress would act promptly to end the use of DDT and save the national bird. But it was not until 1973 that Congress passed a law banning the use of DDT. In the same year it also passed a law that made it a crime to harm certain birds and animals, including the bald eagle, that were considered to be in danger. In 1994, bald eagles were removed from the list of animals and birds in danger of dying out. A careful count made in 2001 revealed that there were over five thousand pairs of bald eagles in the Unites States.