Bald Eagle/American Eagle
The Bald Eagle was officially declared the National Emblem of the United States by the Second Continental Congress in 1782. It was selected by the U.S.A.'s founding fathers because it is a species unique to North America. Ben Franklin wanted the wild turkey to be the national bird, because he thought the eagle was of bad moral character. The Bald Eagle has since become the living symbol of the U.S.A.'s freedoms, spirit and pursuit of excellence. Its image and symbolism have played a significant role in American art, folklore, music and architecture.
Color and Size
The feathers of newly hatched Bald Eaglets are light grey, and turn dark brown before they leave the nest at about 12 weeks of age. During their third and fourth years, Bald Eagles have mottled brown and white feathers under their wings and on their head, tail and breast. The distinctive white head and tail feathers do not appear until Bald Eagles are about 4 to 5 years old. Their beak and eyes turn yellow during the fourth and fifth year, and are dark brown prior to that time. Bald Eagles are about 29 to 42 incles long, can weigh 7 to 15 pounds, and have a wing span of 6 to 8 feet. This makes them one of the largest birds in North America. Females are larger than males. Bald Eagles residing in the northern U. S. are larger than those that reside in the south. They have a life span of up to 40 years in the wild, and longer in captivity.
Habitat and Range
Bald Eagles live near large bodies of open water such as lakes, marshes, seacoasts and rivers, where there are plenty of fish to eat and tall trees for nesting and roosting. Bald Eagles have a presence in every U. S. state except Hawaii. Bald Eagles use a specific territory for nesting, winter feeding or a year-round residence. Its natural domain is from Alaska to Baja, California, and from Maine to Florida. Bald Eagles that reside in the northern U. S. and Canada migrate to the warmer southern climates of the U. S. during the winter to obtain easier access to food, especially fish. Some Bald Eagles that reside in the southern U. S. migrate slightly north during the hot summer months.
Bald Eagles feed primarily on fish, but also eat small animals (ducks, coots, muskrats, turtles, rabbits, snakes, etc.) and occasional carrion (dead animals). They swoop down to seize fish in their powerful, long and sharp talons (approximately 1,000 pounds of pressure per square inch in each foot). They can carry their food off in flight, but can only lift about half their weight. Bald Eagles can fly at speeds of about 65 miles per hour in level flight, and up to 150 or 200 miles per hour in a dive. They can fly to altitudes of 10,000 feet or more, and can soar aloft for hours using natural wind currents and thermal updrafts. Bald Eagles can swim to shore with a heavy fish using their strong wings as paddles. However, it is also possible that they can drown if the fish weighs too much.
Bald Eagles are monogamous and mate for life. A Bald Eagle will only select another mate if its faithful companion should die. They build large nests, called eyries, at the top of sturdy tall trees. The nests become larger as the eagles return to breed and add new nesting materials year after year. Bald Eagles make their new nests an average of 2 feet deep and 5 feet across. Eventually, some nests reach sizes of more than 10 feet wide and can weigh several tons. When a nest is destroyed by natural causes it is often rebuilt nearby. Nests are lined with twigs, soft mosses, grasses and feathers. The female lays 1 to 3 eggs annually in the springtime, which hatch after about 35 days of incubation. Hunting, egg incubation, nest watch, eaglet feeding and eaglet brooding duties are shared by both parents until the young are strong enough to fly at about 12 weeks of age. Eaglets are full size at 12 weeks of age. Only about 50% of eaglets hatched survive the first year.
Bald Eagles were once very common throughout most of the United States. Their population numbers have been estimated at 300,000 to 500,000 birds in the early 1700s. Their population fell to threatened levels in the continental U.S. of less than 10,000 nesting pairs by the 1950s, and to endangered levels of less than 500 pairs by the early 1960s. This population decline was caused by humans. The mass shooting of eagles, use of pesticides on crops, destruction of habitat, and contamination of waterways and food sources by a wide range of poisons and pollutants all played a role in harming the Bald Eagle's livelihood and diminishing their numbers. For many years the use of DDT pesticide on crops caused thinning of eagle egg shells, which often broke during incubation.
Protection and Conservation
Strong endangered species and environmental protection laws, as well as active private, state and federal conservation efforts, have brought back the U.S.A.'s Bald Eagle population from the edge of extinction. The use of DDT pesticide is now outlawed in the U.S., although still used on crops in South America. This action has contributed greatly to the return of the Bald Eagle to America's skies. There are now over 5,000 nesting pairs and 20,000 total birds in the lower 48 states. There are over 35,000 Bald Eagles in Alaska. The Bald Eagle is presently protected by the Endangered Species Act of 1973, Bald Eagle Protection Act of 1940, Migratory Bird Treaty Act of 1918 and the Lacey Act. It is listed as a "threatened" species in the lower 48 states. Although Bald Eagles have made an encouraging comeback throughout the U.S.A. since the early 60s, they continue to be harassed, injured and killed by guns, traps, power lines, windmills, poisons, contaminants and destruction of habitat. Public awareness about their plight, strict enforcement of protective laws, preservation of their habitat, and support for environmental conservation programs can assure a healthy and secure future for the U.S.A.'s majestic and symbolic national bird.