Eagle Recovery: Plans in the Chesapeake Bay Region

Bald Eagle Recovery Plans were implemented, primarily during the 1980s and 1990s, in each of five unique Bald Eagle Recovery Regions.  These regions were: Chesapeake Bay Region, Northern States Region, Pacific States Region, Southeastern States Region, and the Southwestern States Region. Click on any region to find out more information. The Chesapeake Bay Region plans are given on this page.

The Chesapeake Bay Bald Eagle Recovery Team was put together to make a plan to help the bald eagle recover in this area. Recover means to get back. The team wants to get back to the same number of bald eagles that lived in this area in the past.

Part One: Background/General Biology

1. The Area
   The Chesapeake Bay is a shallow, inland sea. It covers 3,237 square miles and has 5,620 miles of shoreline. The entrance to the Atlantic Ocean is 12.5 miles wide. The water is brackish, which means that the Bay is a mixture of fresh and salt water. The salt water comes from the ocean and the fresh water from the many rivers that empty into the Chesapeake. Forty-eight rivers and countless creeks drain into the Bay through many marshes and swamps.


2. Bald Eagles in the Bay
   1. Feeding sites. In the Chesapeake Bay Region, the bald eagle feeds along river, lake, and bay shorelines. When the eagles are not soaring high up over the water, they perch in the trees along the shore. They can also be found near fresh water marshes perched on hills, muskrat houses, or on mud or sand bars.
   2. Nesting sites. There are many different types of bald eagle nest sites in the Chesapeake Bay Region. Most nest sites are in the middle of large wooded areas or along the edges of the woods overlooking the water. Other bald eagle pairs build nests in trees which stand alone in marshes, farms, and areas that have been logged. Nest sites are usually far away from places where humans farm, boat, hunt, fish, and lumber, but some nests have been found near railroad tracks, roads, airplane runways, and houses. Most eagles build nests less than 1 mile from feeding areas, but some nests are between 1 to 2 miles from the birds' main food source.
   3. Roosting sites. Roosts are places where eagles gather. Only two roosts have been found in the Chesapeake Bay Region. One roost was in a forest in Virginia. In the winter of 1952 thirty-one eagles were seen at this roost.
      
      
3. Nesting
   Most nest building and repair in the Chesapeake Bay Region takes place from November through January. Sometimes nest building begins in February, May, June, or early fall, but in these cases eggs were not laid in these nests that same year. Fresh sticks and lining are often added to the nest while the adults are sitting on the eggs.
   
   Eggs are laid between mid-January and Mid-March. Most eggs are laid in February, and hatch in April. The young fly by the end of June or early July. Bald eagles in the Chesapeake Bay Region usually lay one to three eggs, though there have been a few reports of the eagles laying four.
   
   At least four active bald eagle nest sites in the Chesapeake Bay Region are known to have been active for 60 years or more. An active nest is a nest where an adult eagle has been seen sitting on eggs. Of course these sites were used by more than one pair of eagles. Two of these sites are in Maryland and two are in Virginia.
   
   Active nest areas have been seen as close as .75 miles from each other. This close nesting takes place mostly in large forests where no one bothers the eagles. In most of the Chesapeake Bay Region the nests seem to be spaced about 5 miles from each other.
   
   In the Chesapeake Bay Region, bald eagles use different kinds of trees to build their nests. Pines are used most often. Other tree types used are oak, tulip poplar, beech, and hickory.
   
   Although bald eagle nests have been found in dead trees in the Chesapeake Bay Region, it is thought that the trees died after the nests were built. A lot of eagle nest trees die after a few years of use. When this happens, most eagles will leave their nests, but usually one or two years after the tree has died. There are only two reported cases in the Chesapeake Bay Region of bald eagles nesting on man-made structures, both on wooded towers built by the U.S. Army. There have been no reported cases of bald eagles building nests on the ground, as they sometimes do in other areas.
   
   A bald eagle's nest in a tree is usually 50 feet or more above the ground in the highest triple limb crotch. Branches above this form a cover over the nest which shades the birds and their young from the sun and bad weather. The nest must be easy to get to so the area around the nest must be clear. Some nests have been seen on the very top of the tree. These nests have problems with strong winds, and bad weather. Sometimes these nests are blown apart by a storm.
   
   Most nests are built with sticks about 1 inch around and three feet long. The center of the nest is filled with cattails and marsh grass clumps including the roots and dirt. It is lined with fine grasses, often the broom sedge. Green pine needles and leaves are often placed in the nest cup before eggs are laid. Eagles have also been seen putting these things in the nest after they leave it. Nests are usually shaped like a wine glass and a new nest is about 2 feet deep and 5 feet across. New sticks and other types of material are added to the nest each year so that an 8- to 10-year-old nest which has been used every year may be 6-8 feet deep and 6-8 feet across.


4. Food
   Bald eagles in the Chesapeake Bay Region eat mostly fish, water birds, and muskrats. Catfish seems to be their favorite fish. They also eat turtles and other small mammals like rabbits.


5. Numbers of Bald Eagles and their Young
   Scientists did a study to see if the numbers of bald eagles and their young was different from one year to another. In 1962 they found that from the 37 nests that they studied, only 7 babies hatched and learned to fly. In 1936, out of 39 nests, 67 baby eagles were hatched, and 64 learned to fly. Scientists were surprised to find such a big difference in the number of baby eagles that lived. They wanted to know why so few baby eagles were surviving.
   
   By 1970 field workers found that from 55 nests only 22 eagle babies lived to fly. This was better than 1962 but a lot worse than 1936.
   
   The way scientists compared one year to another was to divide the number of eagles fledged , which means to hatch and live long enough to fly, by the total number of active nests. Using this math, they got a 1.6 for 1936, 0.2 for 1962, and 0.4 for 1970. As you can see, there were a lot fewer eaglets surviving in 1962, and it was only a little bit better in 1970.
   
   Not only had scientists noticed that there were fewer baby eagles but there were fewer adults as well. By the early 1950s people all over the country were seeing fewer bald eagles. But what really worried scientists was the small number of young eagles. They knew that, without young, the bald eagle would eventually be wiped out completely.
   
   By 1977 0.8 young for each active nest were fledged. This is about half the number of young that survived in 1936. This was better than 1962 but still not back to normal.


6. Bald Eagles on the Move
   During the spring and summer many Florida bald eagles come to the Chesapeake Bay Region. In the fall and winter bald eagles from Canada and northern parts of the United States come down to the Chesapeake. Some of these may be Florida birds on their way back south.
   
   Young bald eagles from the Chesapeake Bay Region seem to travel to many places. Three young eagles that were marked by researchers were found in Ohio, Massachusetts, and North Carolina. Other marked birds were found in Ontario and in northern Pennsylvania.


7. Animals that Eat Eagles - Predators
   Animals that kill other animals, usually for food, are called predators. Adult bald eagles have no predators other than humans, but eagle eggs and young eagles are sometimes killed by other animals. One study reported that young and eggs were eaten by bobcats and raccoons in Florida. Another study stated that young eagles did not fly very well at first. Often a young eagle will simply glide to the ground and stumble around. At this time it is possible that a predator could attack the bird.


8. Eagles and Other Birds
   Many people have seen smaller birds like crows and gulls attacking eagles. One time someone saw about 200 starlings flying around two eagles. The eagles didn't pay any attention to the starlings. After a while the starlings flew away. A researcher reported that he saw both red-tailed and rough-legged hawks around eagles. The eagles paid little attention to them. Sometimes crows and eagles will feed in the same area. Bald eagles do seem to be afraid of golden eagles. One scientist saw a bald eagle kill a turkey vulture that was near its nest. But usually, bald eagles don't seem to be bothered much by other birds.


9. Eagles and Other Eagles
   Sometimes eagles will fight other eagles. Usually this occurs in areas where many eagles are roosting or feeding. Though it is rare, there have been cases reported of one bald eagle killing another. When they are young they will sometimes fight with other eaglets in the nest. When eagles are hatched in captivity, which means in a man-made zoo or hospital, they often fight with other baby eagles.


10. Parasites
    Bald eagles are attacked by parasites. These are usually small worm-like creatures called helminths. Parasites live off other animals like the bald eagle. Scientists feel that some eagles are killed by parasites but that most die of other causes. One scientist suggested that the reason adult eagles have different nests in the same area is to get away from parasites like ticks that might live in one nest and not in another.


11. Diseases
    Sometimes bald eagles are killed by diseases such as cholera. Some eagles eat a lot of sick and injured birds. If the birds have cholera, the eagle can catch it, too. Pneumonia and other diseases kill a few eagles each year.


12. Competition
    There seem to be plenty of nest sites in the Chesapeake Bay Region, so there isn't much competition between eagles or other birds. Sometimes a great horned owl has been known to take over an eagle's nest. When this happens the eagle just goes to another nest in the area. One scientist reported that a great horned owl hatched an eagle's egg with its own eggs. There have been other reports of an eagle hatching an owl egg. Virginia ospreys will sometimes take over an eagle's nest, also. Competition for food with other predatory birds does not seem to be a real problem for the bald eagle. The bald eagle can eat many different types of food. Harsh winters are the real source of problems for the eagles when it comes to food, as the winters may kill off many of the animals that eagles like to eat.


13. Weather
    Some scientists think that cold weather in the winter and spring makes it hard for the eagles to breed successfully. Storms are also a threat to nesting eagles. After a hurricane in Florida one scientist reported a big drop in the number of successful nests.


14. Accidents
    Many bald eagles are killed in accidents each year. A lot of eagles hit power lines. Sometimes eagles run into aircraft.
    
    One scientist studied 475 dead bald eagles and found that 95 deaths were caused by accidents.


15. Why Were Bald Eagles Dying?
    Even though a certain number of bald eagles were dying from accidents and disease, there had to be other things that were killing bald eagles. One scientist suggested that the poison DDT, which was being used to kill insects, was killing eagles as well. DDT was getting into the eagle's food chain. This happens when DDT is sprayed on plants and the insects that eat these plants are eaten by fish and animals that the eagle eats. Also, when it rains, DDT is washed off the farmlands into the water where fish live. This poison gets into the fish and, when the eagle eats the fish, the DDT gets into the eagle as well.
    
    Scientists gathered eggs that didn't hatch from their nests. These eggs were thinner than normal and shown to have higher levels of DDT than normal eggs. There were other poisons that were found in dead eagles. PCB and mercury were found in many of the eagles studied. Lead poisoning was also killing eagles. When a hunter shoots a bird with lead shot and the wounded bird gets away to be later eaten by a bald eagle, the eagle gets lead poisoning and may die. Scientists started to realize that things in nature were connected. By poisoning one animal we could poison the animal that eats that animal as well. Big companies had been pouring waste products into the Chesapeake and the rivers feeding into the Chesapeake for years. Many of these wastes were highly poisonous. Scientists were finding these poisons in the livers of bald eagles who had died.
    
    
16. Oil
    As more and more oil companies were moving oil across the Chesapeake Bay, eagles were at risk of coming in contact with oil slicks. If their feathers became oiled, the eagle could get some oil on the eggs. Even a small amount of oil was shown to stop bird eggs from hatching.


17. How People Affect Eagles
    Scientist worry about the future of the bald eagle. Here is a list of some of the problems people cause for the bald eagle.
    
    
    1. Building activity - Between 1950 and 1970 the number of people living around the Chesapeake Bay went from 6 million to 9.2 million. More people meant more houses, roads, parks, airports, and other buildings. These buildings were getting closer and closer to where the eagles lived. Also, people wanted to live by the water. This is exactly where bald eagles live and breed.
    2. Boating activity - A lot more boats were coming into the Chesapeake Bay Region. From 1963 to 1973 the number of motorboats more than doubled. Added to this were an uncounted number of sailboats, which sailed around the Bay and into the rivers that fed into it. The number of marinas, which are places where people keep their boats was also growing. All these people and their boats was a possible disturbance to the eagles, especially when they are nesting.
    3. Fishing - Fishermen bother eagles as well as other types of boaters. Bald eagles and other birds also sometimes get tangled up in fishing lines and hooks.
    4. Trapping - Some eagles are caught in traps set for wolves, foxes, and muskrats.
    5. Hunting - Hunting for game birds and animals bothers nearby eagles. Hunting during nesting season, from December through February, can be very hard on eagles and their young.
    6. Shooting - Many eagles are shot to death each year. One scientist looked at 400 dead eagles from 1960 to 1975 and found that about half of those had been shot.
    7. Nature Observation - People who like to look at eagles sometimes get too close and make so much noise that they bother the eagles.
    8. Cutting Down Trees - Cutting down trees near eagle nests or roosting sites can have a very bad effect on the eagles. If people cut down the tree in which a pair of eagles have built a nest and there are no other good trees in the area, the eagle pair may stop breeding altogether.
    9. Farming - Farmers cut down trees as well. This can lead to a loss of eagle nesting sites. Also, use of chemicals by the farmers can harm a bald eagle if the chemicals get into the food chain.

Part Two: Recovery Plan Outline
Plan goal: To have the bald eagle's classification changed from endangered to threatened.
Plan objectives: 1. To have 175-250 pairs of nesting bald eagles in the region. 2. For each pair to raise at least one eaglet.

Below is a list of things people must do to help the bald eagle recover. The list has eight main parts. Each part has a list under it which describes what must be done to help the eagle recover.

1. Education:
   The purpose of this section is to find ways to share information with people and different groups so everybody knows about bald eagles. Then, we can all work together to create a better future for the eagle.
   1. Send out news stories about the bald eagle. Let everyone know what's going on with the eagle in the Chesapeake Bay Region.
   2. Give presentations to schools, clubs, and other interested groups.
   3. Have a fact sheet ready to send out for people who call or write for information.
   4. Get on the radio and TV to tell people about the bald eagle's problems and what they can do to help. Tell them not to bother eagles, especially when they are nesting, and who they can call to share information about bald eagles they might have seen.
   5. Help other bald eagle recovery teams to make films about eagles in their area.
   
   
2. Surveys:
   A survey is a study. Surveys will be made to find out how the bald eagles are doing. An aerial survey is a survey done from an aircraft.
   1. Check all nesting pairs of bald eagles in the Chesapeake Bay Region every year. Also check on eagles that live in this area but do not breed.
   2. Aerial and ground surveys will be made from December to February, which is when most new nests are built and old ones are repaired. Check all active nests by doing an aerial survey. These are nests where adult bald eagles were seen sitting on their eggs during the period from February 15 to March 25. Check them again in April to see how the baby eagles are doing.
   3. Check the active nests again in May-June to get the final results of bald eagle nesting.
   4. Do aerial and ground surveys in December-January and May-July to check places where bald eagles gather, like roosting sites.
   
   
3. Research:
   Keep doing research on the bald eagle in the Chesapeake Bay Region. Find out as much as possible about the bird.
   1. Check on what prey the eagles are eating. Prey is an animal that is hunted and taken for food. Visit the eagles' nests to find the remains of any animal the eagle has eaten. Do this during the non-breeding season so eagle babies are not disturbed. Find out what the eagle is preying on at different times of the year.
   2. Check the eagle's prey. Do studies to find out if the prey has any poison in it.
   3. Check the water quality in areas where bald eagles live. If there are poisons, find out where they are coming from.
   4. Collect any eggs that haven't hatched. Check these eggs for poisons.
   5. When a dead eagle is found, try to figure out what killed it.
   6. Try to find out if Kepone is killing bald eagles. This poison was found in the James River which feeds into the Chesapeake Bay. The eagles along this river are almost gone.
   7. Find out more about where eagles go. Where do they go during different seasons? Where do young eagles build their nests?
   8. Put bands around eagle legs and color-mark eagles. This helps to study where the eagles go and what they are doing. Also put radio transmitters on young eagles to find out where they go.
   
   
4. Help for the Nest:
   Eagles can be helped by placing eggs and young in their nests. These eggs and young come mostly from zoos, animal hospitals, and nature sanctuaries. When eagles are taken care of by people and are not in the wild, they are said to be in captivity.
   1. Some of the eggs raised in captivity will be put in nests where eagles haven't been able to produce any young. This can be done with eagles from 2 to 8 weeks of age.
   2. Eagles from 7 to 9 weeks of age can be brought back to an area for hacking, which is a special way to release eagles so that they return to nest there.
   3. Sick and injured birds will be taken care of until they can be released.
   4. Eagles that live but cannot be returned to the wild will be used for research, for captive breeding, or in zoos.
   
   
5. Taking Care of the Land Where Eagles Live - Habitat:
   It seems as though there is enough habitat for more than 175 pairs of birds. Land that could be used in the future must be protected as well.
   1. Find the best places for eagles to live. This includes places where the eagles used to live but don't right now.
   2. Find out what all eagle habitats in the Chesapeake Bay Region have in common. Are they nesting in a certain kind of tree? What kinds of human activity goes on around them? How far are the nests from water? These kinds of questions should be answered so scientists can give a description of the habitat that is most used by bald eagles in the Chesapeake Bay Region.
   3. Find out about habitats in other regions. How are they similar or different to places in the Chesapeake Bay Region?
   4. Describe the areas around successful nests. What do they all have in common?
   5. Look for new areas where eagles might want to live.
   6. Make plans to protect the land around active nests and roosts.
   7. Make plans to protect the land around old nest sights or possible future sites.
   8. Give rewards and encourage private land owners to protect the eagle.
   
   
6. Protecting the Eagle:
   Keep people from harming eagles.
   1. Keep people from shooting the eagle. Educate them as much as possible. Let people know that the bald eagle is an endangered species. Make sure everybody knows it is against the law to shoot an eagle.
   2. Punish people who break the law.
   
   
7. Poisons in the Environment:
   Poisons in the environment kill many eagles each year.
   1. Try to keep hunters from using lead shot in their guns. When they injure or kill a bird with lead shot and a bald eagle eats the bird, it gets lead poisoning.
   2. Report any illegal dumping of poisons that might end up in the eagles' food supply.
   
   
8. Disease:
   Try to keep disease away from the bald eagles by trying to keep diseased prey away from the eagles. Also check any dead eagles for disease.
   
   Researchers feel that if they follow the points in the Chesapeake Bay Recovery Plan, then the bald eagles there have a good chance of recovery. If the plan goes well, the eagle will no longer be listed as endangered. The bald eagle in this area will then be listed as threatened.