Bald Eagle


Haliaeetus leucoceephalus


By: Sean

Classification

Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Falconiformes
Family: Accipitrdae
Genus: Haliaeetus
Species: leucoceephalus




Natural History
    
The bald eagle has been the national bird since 1782. Before European settlers came to America there were half a million bald eagles. They lived along the Atlantic from Labrador to the southern tip of Florida, and from California to Alaska. They live around big rivers and lakes. Bald eagles lives in 45 of the 48 lower states. There was a large number of bald eagles on the coast of Maine.  
      
The more people that came to America the more the bald eagle population declined. The bald eagle drastically decreased  in the late 1800’s when people started expanding west, which destroyed the bald eagles' natural habitat and the bald eagle got hunted by pioneers more. People finally started to notice that the bald eagles were dying in the 1930’s, so the Bald Eagle Act was passed in 1940. This helped the bald eagle population increase.

But  DDT was becoming more and more popular. DDT is a chemical that keeps bugs off people’s crops, but it can be deadly when consumed. It was sprayed on plants, then eaten by little animals and later eaten by bald eagles, which hurt both the bird and  eggs. DDT made the eggs shell too thin, so when the bald eagle tried to warm the egg it cracked. But even if the eggs didn’t crack, the baby bald eagles would die due to the high level of DDT.

Over 100,000 bald eagles were killed by fishermen from 1917 to 1953 in Alaska. The fishermen killed the bald eagle because they were afraid that the bald eagles would eat all of the salmon that the fishermen were hunting. In the 1960’s and 70’s more and more states put the bald eagle on the Endangered Species List. On July 4th, 1976, a bicentennial of the date America became a country, the bald eagle was officially on the Endangered Species List. In 1995 the bald eagle’s status had improved to threatened.

Habitat
    
Bald eagles are mostly located in  areas of North America that have some type of water nearby. They like to live on top of the tallest trees. Their nests are called eyries. The bald eagle’s nest can weigh up to 1 ton! They have a wide range of habitats from trees and fresh water lakes and rivers, to swamps and mangroves in Florida and to the deserts on the Baja Peninsula in Mexico.
    
Inland bald eagles migrate south in the winter. One researcher estimated that for every mile along the Chesapeake Bay there was a bald eagle. They like to live where there are not many humans around to interfere . Bald eagles always live near fishable and clean waters. Experts say there may be 25 thousand to 75 thousand nesting bald eagles in the lower 48 states. Even our very own Casco Bay may have a few bald eagle nests.

Present Status
    
The bald eagle is a threatened species, on both the federal and state Endangered Species List

Physical Description
    
The bald eagle’s eyesight is 3-4 times sharper than ours and they can see 4-8 times farther. Their eyes are fixed in their sockets, which means they can’t turn their eyes. To make up for that, they can turn their heads all the way around.

The bald eagle has a backbone, which makes it vertebrate. Their beak is very strong and very hooked. It is powerful enough to tear the flesh of  carrion into bite-size pieces. They weigh 6.6 to 13.9 pounds. They usually are 30.4 to 36.4”  tall with a wingspan of  5.5 to 8 feet. They have very large beaks, talons, and feet with tiny spikes called spicules, which help stick and grasp slippery fish. Their hearing is probably just as good as a human’s hearing, but their smelling and tasting are worse than a human’s.

Female bald eagles are generally larger than the males. Bald eagles that breed in the south are usually smaller than the ones that breed in the north. Male and female bald eagles usually have the same color feathers. Adult bald eagles have very dark brown feathers, almost black,  and they have white feathers on their heads and tails. Their beaks, eyes, and legs are all yellow. It takes about 4 to 5 years for the bald eagle’s feathers to turn to their adult feathers.

Diet and Feeding Habitats

The bald eagle likes to eat their prey alive. The bald eagle is a consumer and a predator. They watch for fish to swim to the surface, which isn’t very hard to do for them considering they can see a fish on the surface of the water from 1 mile away. Then the bald eagle swoops down to the water and at the last second grabs the fish with their feet, their talons digging into the unsuspecting prey. It then takes their prey to a perch to eat.

In autumn when the salmon are swimming upstream to lay their eggs and die as many as 2,000 bald eagles come  to take advantage of the tired salmon. If their not eating fish they will probably eat seabirds, waterfowl, mammals, reptiles, ducks, wading birds, turtles, rodents, and snakes.
 
The bald eagle’s lifting power is up to four pounds. Though they like their food alive, they take advantage of dead animals, which makes them a scavenger. Their hunting area is an area of 1,700 to 10,000 square acres around their homes. The bald eagles’ diet mainly consists of fish, up to 90%. Some bald eagles can see a fish come to the surface from up to 1 mile away. Their back talons can be up to 1 inch long and can kill their food almost instantly. Their small prey is eaten whole. The bald eagle can also survive by stealing from other eagles or animals. They throw up what they can’t digest, like fins, scales, fur, bones, feathers, and teeth.

Threats

The bald eagle has many threats, both natural and manmade. The bald eagle has been shot by  hunters both accidentally and for their feathers and talons. One big problem is flying into power lines. Their wingspan is large enough so that their wings can touch two power lines which gets them electrocuted. Bald eagles  have been killed by lead poisoning by eating animals that have been shot. Bald eagles have been killed many times by getting hit by cars. They are sometimes threatened with starvation, but that happens mostly in the winter. Bald eagles are threatened by drowning when they misjudge how far they are away from the water when they are hunting or the fish was too heavy for them.

To protect the bald eagle, organizations  have made natural parks ands reservations for them to breed and to live in. It is illegal to hunt the bald eagle in all states. Animal rescue organizations have taken in young bald eagles and cared for them until they mature. Bald eagles have been taken in when they were sick or hurt and released when they are better. If the bald eagle’s population continues to grow it is possible that they will become a Species of Concern.

Personal Essay    
    
The bald eagle is truly an all American bird. It was declared an endangered species exactly 200 years from the date the United States was declared a country. They have even appeared on the back of the American quarters.

Diversity strengthens a ecosystem in many different ways. With diversity there is more difference in a community so there is more than one animal in that specific community. It also makes the food chain much stronger because with a diversity of animals there is more choice of what an animal can eat, if an animal becomes extinct then its predator has to find something else to eat. With diversity there is more choice for that predator to eat.

Bibliography

1. Canadian Wildlife Service Hinterland Who’s Who. May 15th 2002 . www.cws- scf.ec.gc.ca/hww-fap/hww-fap.cfm?ID_species=4&lang=e. (March 3rd, 2003.)

2. American Bald Eagle Information. 2003. ht.://baldeagleinfo.com/. (March 1st, 2003)

3. The Bald Eagle. 2002. ht.://nature.org/wherewework/northamerica/states/illinois/
docks/eagles.html. ( March 23rd, 2003)

4. What do Bald Eagles Eat? Dinner’s Ready!. February 18th,1998. www.indiana.edu%.2f%7ebradwood%2feagles%2feat.htm&s=a. (March 3rd, 2003)

5. “BALD EAGLE.” Wildlife Explorer. 1998. 

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