Species of the Month, December 2014: Bald Eagle

Note: This is the 12th post in our "Species of the Month" series, written by Park Ecologist Peter VanLinn. It's one of several 2014 initiatives meant to share knowledge we have about the Park with those who love it.  

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Why not end the year with one of the most iconic species in the U.S. — the bald eagle. This time of year is ideal for eagle viewing and it is not uncommon to see a bald eagle soaring over the Emerson Grand Basin or other parts of the waterway in Forest Park.  

Many bald eagles rely on the Mississippi River and surrounding areas for breeding, nesting and feeding this time of year; the waterways in Forest Park provide a nice buffet for those eagles who venture this far east of the river. Keep a lookout for them as you stroll through the Park, or join one of the many gatherings coordinated in part by the Missouri Department of Conservation, known as eagle days. You can find out more here.

Bald Eagle (Haliaeetus leucocephalus)
Family: Accipitridae

Forest Park Locations: Commonly spotted above or near the Emerson Grand Basin at the foot of Art Hill. Other locations include anywhere along the Park waterway, Deer Lake natural area, the prairie near Steinberg Skating Rink and the Kennedy Savanna.

Photo © Raymond Lee, Edmonton, Alberta, Canada, January 2011

Identification

• Description: A large, heavy-bodied blackish-brown eagle with a large white head and tail with a long, hooked yellow bill. Adults have a dark brown to black color on the body and wings with bright yellow legs and bill and white head and tails. Juveniles have mostly dark heads and tails with a body being mostly brown but mottled with white in varying patterns and amounts. Young birds attain adult plumage at 4 to 5 years old. 

• Height: 28-37 in. (71-96 cm)
   
• Wing Span: Up to 7 ft. 6in. (2.3 m)
   
• Longevity: Average of 15 to 20 years, up to over 30 years.
   
• Call: A variety of calls, but commonly a series of high-pitched whistling or piping notes. Occasionally a low “kuk-kuk-kuk” call is used.
   
• Distribution: Widespread across North America from Alaska and Canada down into northern Mexico. In Missouri bald eagles are observed statewide, usually near lakes, rivers and wetlands and particularly during the winter.
   
• Status: In Missouri the bald eagle is considered an uncommon migrant, but nationally status is resident to long-distance migrant. Bald eagles are a species of conservation concern in Missouri.
   
• Habitat and Conservation: Bald eagles usually live near large water bodies including rivers, lakes, reservoirs, and coastal regions. Nesting typically occurs in a wooded area adjacent to water. Preferred perching occurs in large, mature conifers and deciduous trees as well as an occasional upland near water. 
   
• Life Cycle: Bald eagles reach maturity from age 4 to 5 and usually breed near where they were born. Generally a pair will mate for life. Courtship includes special calls and flight displays. Nests can be very large, as big as 13 feet deep and 8 feet across. A pair will produce 1–3 eggs annually with a 3 week incubation period, but rarely do all three chicks reach maturity. Hatchlings fledge at about 10–12 weeks. Parents share the responsibilities of protecting and providing for young.
   
• Food: Diet mainly consists of fish and carrion, but they will also eat small mammals and birds. Bald eagles are scavengers and will aggressively steal food from other creatures.
   
• Human Connections: The bald eagle not only stands as a cherished symbol of the U.S., it also represents a great conservation success story. Once numbering 20,000 mating pairs, the bald eagle population dwindled down to only 417 mating pairs in the lower 48 U.S. states. Current estimates put mating pairs at near 10,000 and a global populations in the hundreds of thousands. Native American cultures have also held the bald eagle sacred and saw their feathers as important symbols.
   
• Ecosystem Connection: Bald eagles are a keystone species, top predators of fish and important scavengers.

Note: Information for this post has been collected from The National Audubon Society; The Cornell Lab of Ornithology; and The Missouri Department of Conservation Field Guide.