Bald Eagle.

BALD EAGLE (Haliaeetus leucocephalus)

Breeds from Alaska through all of Canadian provinces and along both coasts of the U.S., in Great Lakes states, along Rockies south to Wyoming, locally in central Arizona, and irregularly in rest of U.S. interior. Winter throughout breeding range, though mostly in coastal areas. Also winter along upper Mississippi. Top

Bald Eagle Identification

The American Bald Eagle has the distinctive white head and tail after the fourth or fifth year. When they are juvenile or immature they are a mottled brown. First year bald eagles may have a mottled white belly. Immature bald eagles may be mistaken for Golden Eagles. Bald eagle heads appear to be substantially greater than half the tail length, more like 2 thirds, whereas Golden Eagle heads are barely 1/2 as long. All when seen from below on a bird in flight. Bald Eagles have excellent eye sight, as do all raptors. Eagles, and other hawks, have a two fovea in each eye...two centers of focus on the retina. The "regular" one is for focusing on the horizontal plane. The other is higher on the retina and concentrates focus toward the ground. The birds not only see and process two images, one from each eye, as do most animals with eyes on the sides of their heads, but they also process two more images from below themselves... four things at once. That explains why a perched bird will sometimes turn its head completely upside down when looking skyward. The ground-image fovea is then looking up. Talons are extra-large and grooved underneath, and the foot pads rough, almost spiculate (needle-like), for increased grasping ability, vital when the prey is a large slippery fish. The beak is very heavy (fishing eagles have some of the most powerful beaks.
A pair of Bald Eagles will remain together for each nesting season as long as both are alive. They engage in various greeting and courtship flights, the most spectacular of which consists of locking talons in midair and descending for several hundred feet in a series of spiraling somersaults. They utilize feeding, day roost and night roost perches, and there is a definite dominance hierarchy for their use. Two adults sitting in close proximity will almost certainly be a pair. When hunting a raft or water birds, they will often pendulum over the group. This works well to intimidate the members of the raft, often sending one or more into panic, making them an easy mark. Top 

SIZE: LENGTH: 34-43 inches
WINGSPAN: Male: about 6 1/2 feet; Female: about 7 feet
WEIGHT: Male: 9 lb.; Female: 12.8 lb.
LIFE EXPECTANCY: 50-60 years  Top

HABITAT

Bodies of water with large trees nearby and some freedom from disturbances while nesting. Top

REPRODUCTION

Pick largest tree in a stand of trees near water, with an open view of area. Nest trees are usually less than 1 km from water. Require freedom from human disturbance in order to nest. Nest are built on average 82 ft. from ground. Nest on sea stacks, peninsular ridges, islets, or hillsides which provide height and isolation in coastal Alaska and Aleutian Islands where there are no trees. Lay eggs between October (southern parts of range) and May. Lay 2 eggs 2-4 days apart. Northern populations have laid 3 or 4 eggs in a nest rarely. Incubation period of 35 days. Both sexes incubate, with female doing more of the work. Young stay in nest 10-12 weeks and are brooded closely at first, then are increasingly left alone while parents hunt for food. Successful fledging of 2 chicks occurs only 3-35% of time. Top

DIET

Fish primarily; birds such as ducks and gulls; mammals such as rabbits, hares, rats, and sea otter pups; carrion Top

BEHAVIOR

Prolonged period of immaturity. They mature at around 5 years of age though 4 year olds have been known to breed. A large number of adults are non-breeders, probably due to competition within the species and variable annual food supply. Southern population is sedentary and probably maintains pair bonds throughout the year. Northern population is migratory and pairs probably separate during winter. Aerial displays include talon locking and spinning descents, pursuit flight, and gyrating sky dancing. Copulation occurs on tree branches or some sort of support. Top

POINTS OF INTEREST

Bald eagles hunt cooperatively, usually when hunting mammals such as rabbits. Distinctive white head and tail in adults. They have 4 methods of catching fish: 1) swooping from perch, 2) swooping from flight, 3) wading from shore and catching prey with talons or beak, 4) and standing at edge of ice catching prey with talons or beak. Can catch fish up to 3 kg (6.6 lbs). The largest fish may be brought to shore by alternating periods of towing or flying with prey for short distances and resting half submerged on water. Juvenile birds have slightly longer wings and tails than adults. When gliding or soaring, wings are held horizontally, unlike golden eagle or turkey vulture which hold wings at an uptilted angle (dihedral). Top

Pictures

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