DESCRIPTION:  The Bald Eagle  is one of North America’s largest raptors with adult females reaching weights of 14 pounds and standing 42 inches tall.  Adult males are slightly smaller.  The bright white head and tail contrasted against dark body feathers are key characteristics used to identify the bald eagle.  However, these white feathers as well as the yellow color of the bill do not develop until the eagles reach sexual maturity at about five years of age.  The eyes, legs, and talons are yellow.  Immature bald eagles are often mistaken as golden eagles because they lack the white head and tail feathers.  

DISTRIBUTION:  Bald eagles occur throughout the continental United States and Canada.  They are also found northwestward into southern Alaska.  In Alabama, bald eagles are found statewide; however, they are concentrated primarily along rivers and large bodies of water.  A January survey of bald eagles in Alabama has averaged about 100-150 birds in recent years.  

HABITAT:  Bald eagles inhabit areas near coasts, bays, rivers, lakes or other bodies of water where food is plentiful. 

FEEDING HABITS:  Eagles feed opportunistically on fishes, injured waterfowl and seabirds, various mammals, reptiles, and carrion.  The majority of their diet is comprised of fish.  They hunt live prey, scavenge, and pirate food from other birds. 

LIFE HISTORY AND ECOLOGY:  Bald eagles mate for life and share all nesting and brood-rearing responsibilities.  Large nests are most often built in the crowns of tall trees, usually near water.  Occasionally, nests will be constructed on the sides of cliffs, however it is uncommon in southern areas.  Typically, breeding pairs will return to the same nests year after year, and repair or restore the nest by adding new material.  Nests are very large reaching 10 feet across and weighing about 2,000 pounds.  One to three eggs are laid in December or January and are incubated for 30 to 32 days.  Relatively small at hatching, eaglets need nearly three months of development before leaving the nest.  Juveniles are about the same size as adults when they leave the nest, but they don’t reach sexual maturity until they are approximately five years of age.  The normal life span of the bald eagle is estimated to be about 30 years. 

REFERENCES:

http://biosource.hertitage.tnc.org

Author:  Kevin Holsonback, Wildlife Biologist, Division of Wildlife and Freshwater Fisheries

The osprey flies over the park too and one day I will photograph them

DESCRIPTION: Ospreys are large raptors having a wing span from 57 to 69 inches. Depending on sex and physical condition, they can weigh from 42 to 70 ounces and at maturity reach lengths up to 23 inches. Ospreys have strong hooked beaks and large feet armed with extremely sharp talons to aid in the catching and eating of prey. Sexes are similar in appearance, with females on average being about 20% larger than males.

The feather coloration is characteristic of all adult ospreys. The head is white on top with a dark brown eye line that broadens behind the eye extending down the nape of neck, back, upper wings and tail. Dark brown mottling on the upper breast produces a necklace affect, being more defined in female ospreys. Adults have a distinctive dark brown patch underneath the wings at the carpal joint or bend in wing. The wing flight and tail feathers have a number of noticeable contrasting white and darker colored bands.

The chin, throat, breast and belly of adult ospreys are bright white. Juvenile ospreys are similar in appearance to adults but have a more speckled coloration and take on adult coloration at about 18 months of age.  Adults have a yellow iris and the juveniles have an orange/red iris. Pale yellow feet and black beak are common for both sexes. The white belly, characteristic crooked wing shape and flight style of ospreys make recognizing them at a distance, relatively easy.

DISTRIBUTION: Ospreys inhabit suitable habitat worldwide and winters and breeds on all continents except Antarctica.

HABITAT: Fish are the primary food item of ospreys. Suitable habitats are lakes, rivers, fresh and saltwater marshes that support good fish populations, with adjacent forested areas to provide nesting and perching sites. Ospreys naturally choose large dead snag trees for nesting sites, but also readily use power poles, channel markers and other suitable man-made structures, that will support their large nests.

FEEDING HABITS: Ospreys have anatomical adaptations to improve their fish catching abilities. Large wings that move freely at the carpel or “wrist” joint allow them to hover easily above water while watching and waiting for the exact moment to dive feet first into the water after unsuspecting fish. Ospreys’ feathers are very oily, to keep them dry when diving into the water after prey. Other adaptations include efficient nasal valves that prevent water from entering their nostrils when submerging after fish.

The bottoms of their feet have many short spines called spicules to help them hold onto prey. The sharp talons are equipped with a reversible outer toe which the osprey can turn around to aid in gripping prey. After a successful catch, the osprey carries a fish head first making it aerodynamic and easier to fly to the nest or favorite perching site. Fish alone make up about 90% of their diet but ospreys have been observed to prey on frogs, snakes, birds and small mammals.  

LIFE HISTORY AND ECOLOGY: Ospreys are migratory but may winter and breed in the same areas, where good stable habitat abounds. Ospreys are capable of breeding at three years of age. They pair and mate for life and may use the same nest site year after year, which both the male and female refurbish. The male when courting the female will perform what is termed the “sky dance”. The sky dance consists of flying around with a fresh caught fish or nesting material to gain the favor of the female osprey. Once the nest site is completed the female will lay one spotted cream colored egg with a complete clutch consisting normally of three eggs. Incubation starts at the time of egg laying and both adults share with the incubation process which takes approximately 40 days. Osprey chicks that hatch first will be larger and stronger than latter born siblings. I

REFERENCES:

Robbins, Chandler S., Bruun, Bretel and Zim, Herbert S., 1966, A Guide To Field Identification, Birds of North America, Golden Press, New York, Pp. 76.

Terres, John K., Heron Family, 1980, The Audubon Society, Encyclopedia of North American Bird, Alfred A. Knopf, New York, Pp.664-646.

Author: Rick Claybrook, Retired Wildlife Biologist, Division of Wildlife & Freshwater Fisheries