Bald Eagle Facts

bald eagle perched in treeI wish that the bald eagle had not been chosen as the representative of our country, he is a bird of bad moral character, he does not get his living honestly. He is therefore by no means a proper emblem for the brave and honest…of America… – Benjamin Franklin

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. As noted above, Ben Franklin wanted the wild turkey to be the national bird, because he thought the eagle “was of bad moral character.”

The Bald Eagle: Haliaeetus Leucocephalus is the only eagle species that is found solely in North America. It is found in every state in the U.S. with the exception of Hawaii. The Bald Eagle has a wingspan of up to eight feet and can weigh up to 15 pounds. It inhabits areas near water where there are plenty of fish (thus the name ‘fish eagle’) to eat and tall trees in which to nest and roost. Bald Eagles are monogamous and remain faithful to their mate until death. Females lay one to three eggs annually in the springtime, and the incubation period is approximately 35 days.

Young (immature) Bald Eagles are dark brown in color when they fledge the nest at about 12 weeks of age. The head and tail feathers turn predominantly white in their fourth or fifth year. Bald Eagles can live up to 40 years in the wild and longer in captivity. They are primarily fish eaters and carrion eaters.

Their phenomenal eyesight – All eagles are renowned for their excellent eyesight, and the bald eagle is no exception. They have two foveae, or centers of focus, that allow the birds to see both forward and to the side at the same time. Bald eagles are capable of seeing fish in the water from several hundred feet above while flying. This is remarkable as most fish are counter-shaded, meaning they are darker on top and thus harder to see from above.

Young bald eagles have been known to make mistakes, such as attacking objects like plastic bottles floating on the surface of the water. Bald eagles are able to find and prey on dead fish much more rapidly than live fish, because dead fish float with their light underside up, making them easier to see.

An eagle’s eye is almost as large as a human’s, but its sharpness is at least four times that of a person with perfect vision. The eagle can see a rabbit moving almost a mile away. An eagle flying at an altitude of 1000 feet of open terrain can spot prey over an area of almost 3 square miles.

Because of the energy expended during hunting, an eagle must also spend time resting quietly. It’s estimated that only one out of eighteen attacks are successful. For a scavenger like the bald eagle, the carcass of a seal is a huge supply of food. Rich with fat and protein, the seal’s body will feed a group of eagles for days. Though many calories will be obtained, they are sometimes lost in fighting over the food with other eagles or vultures.

HABITAT & RANGE: Bald Eagles live near large bodies of open water such as lakes, marshes, seacoasts and rivers, where fish are plentiful and there are tall trees for nesting and roosting. Bald Eagles use a specific territory for nesting, winter-feeding or a year-round residence. It is found 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. such as Florida migrate slightly north during the hot summer months.

FOOD SOURCE & FLIGHT: 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, 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, they may also drown if the fish weighs too much.

bald eagle perched in treeNESTING & BREEDING: 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.

POPULATION SIZE & DECLINE: 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 human intervention. 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.

RECOVERY & PROTECTION: 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.

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