The Bald Eagle

The Bald Eagle (Haliaeetus leucocephalus), can be seen in large numbers along our country’s waterways throughout the winter months (See figure 1). This species was established as our nation’s emblem in 1782 and was common throughout our country (1) with an estimated 100,000 nesting pairs (2).

Bald Eagle Range

Figure 1: Bald Eagle range. Image courtesy of The Cornell Lab of Ornithology http://www.allaboutbirds.org/guide/bald_eagle/id

Only about 40 years ago, this incredible bird was at risk of extinction. Illegal shooting, habitat destruction and prey contamination by DDT and other pesticides threatened the Bald Eagle (3). DDT was restricted in 1972, and so began the journey back from the brink of extinction. In 1978, they were listed on the Endangered Species List (1) with only an estimated 487 nesting pairs left (2). Since their protection, they have made an incredible rebound. Bald Eagles were removed from the threatened and endangered species list in 2007 with an estimated 9,789 nesting pairs. Although these birds are delisted, they are still protected under the Migratory Bird Treaty Act and the Bald and Golden Eagle Protection Act. It is illegal to kill, sell or harm these birds, their nests or their eggs (2). Today, the top five threats to the eagles’ continued recovery are habitat destruction by deforestation and development, poisoning by eating lead bullet killed animals, secondary poisoning by eating poisoned pests, electrocution and poaching(4). When an eagle is injured, organizations like The World Bird Sanctuary in Valley Park, Missouri that can rehabilitate them and other injured birds of prey. Check them out at www.worldbirdsanctuary.org/index.php.

Juvenile and Adult Bald Eagles

Figure 2: Juvenile and adult Bald Eagles in a nest. Photo taken by Mike Black http://yourshot.nationalgeographic.com/photos/3542760

Thanks to the efforts of conservationists and other scientists, we can enjoy these incredible birds. You can identify adults by their trademark brown bodies and white heads and tails. The juveniles do not show this classic appearance until about 5 years of age. Until then, they have mostly dark heads, bodies and tails, but their bellies may have some white mottling (See Figure 2). Both have yellow beaks and legs. When soaring, you identify them by their large bodies and heads (1). Their bodies are about 34-43 inches long with a wingspan between 6-8 feet (5). They hold their broad wings flat like a board when soaring (See Figure 3), and when they flap, they will have a slow beat of the wings (1).

Soaring Bald Eagle

Figure 3 Adult Bald Eagle soaring. Photo taken by Ted M. http://yourshot.nationalgeographic.com/photos/2647395/

Most pictures or video we see of these birds shows them fishing along the rivers. Although their diet relies heavily on fish, they are also opportunistic and will scavenge what is available. I often see at least one on a deer carcass when I return to my home town in Iowa for Christmas. Bald Eagles will also often steal the catch of other birds like Osprey, a smaller fishing raptor (1). Another iconic picture of these birds is their incredible mating flights where the male and female fly high and lock talons. They then spin and tumble down releasing each other only seconds before impact (1).

Eagle Fishing

Figure 4 Adult Bald Eagle catching a fish. Photo taken by Craig Miller http://yourshot.nationalgeographic.com/photos/3759463/

There is evidence that these birds mate for life (5), and it is known that they will use their large nests for multiple years (1). Nests can be around 5-6 feet in diameter and 2-4 feet tall. Although both the male and female collect nest material, it is usually the female who weaves the sticks and places the grasses, moss, and other softer material for filler and padding. The nest is then finally lined with soft feathers for the 1-3 eggs that will be incubated for 34-36 days. The chicks remain in the nest after hatching for 56-98 days and are tended by both parents (1). If you would like to watch eaglets in their nest, there are several live-feed nest cameras that can be viewed from your home computer. Warning, you may find yourself watching them a little too much and not getting much work done. For Bald Eagle cams, you can Google for ones in your area or check out the following websites:

Breeding and nest building times vary according to the location of the pair. The following link contains a PDF from the Fish and Wildlife Service, which shows the breeding times for your area, www.fws.gov/midwest/eagle/pdf/nest-seasons.pdf.

There are several festivals around the country that celebrate these magnificent birds. Some of these include the Eagle Meet and Greet in Alton, Illinois, Bald Eagle Appreciation Days in Keokuk, Iowa and there are many more. Check out this website for some Midwest festivals near you. These usually take place in January and February so make some time to check them out, Bald Eagle Events & Programs Winter 2014-2015. Do you have a favorite eagle-themed festival or event? If so, please share it in the comment section below.

Eagle Chicks

Figure 5: Bald Eagle nest and chicks. Photo taken by Wayne Norman http://yourshot.nationalgeographic.com/photos/3839636/

 

References:

1 “Bald Eagle.” All About Birds. The Cornell Lab of Ornithology, n.d. Web. 03 Oct. 2014. <http://www.allaboutbirds.org/guide/bald_eagle/id&gt;.

2 “Fact Sheet: Natural History, Ecology, and History of Recovery.” Bald Eagle Fact Sheet. U.S. Fish and Wildlife Service Midwest Region, 18 Mar. 2013. Web. 02 Oct. 2014. <http://www.fws.gov/midwest/eagle/recovery/biologue.html&gt;.

3 “DDT and Other Organochlorine Insecticides.” Environmental Contaminants Program, U.S. Fish and Wildlife Service. U.S. Fish and Wildlife Service, 15 Jan. 2014. Web. 03 Oct. 2014. <http://www.fws.gov/contaminants/Info/DDT.html&gt;.

4 Hatcher, Bob. “Eagle Survival – Threats to Survival.” Threats to Survival. American Eagle Foundation, July 2011. Web. 03 Oct. 2014. <http://www.eagles.org/vu-study/survival/threats-to-survival.php&gt;.

5 “Bald Eagle.” Bald Eagle. National Geographic, n.d. Web. 03 Oct. 2014. <http://animals. nationalgeographic.com/animals/birds/bald-eagle/>.

 

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