Bald eagles are North American birds of prey. They are part of the Haliaeetus genus. The Neo-Latin name is derived from the Ancient Greek word haliaetos (ἁλιάετος) that translates to sea eagle. The specific name leucocephalus is formed with the Ancient Greek words leukos (white) and kephalḗ (head). The English word for bald in the bird’s common name relates to the original meaning of having white in the head or face as opposed to hairless.
The bald eagle is endemic to North America. Its natural range covers parts of Canada, northern Mexico and the entire continental United States. There are two recognized subspecies that are split between the north and south. The northern birds are migratory. Southern bald eagles never travel. Most of the Canadian bald eagles live in British Columbia and the forests of Ontario, Manitoba, Alberta and Saskatchewan. Their American relatives are found in every state.
Male and females have the same dark brown plumage and white head. Females are twenty five percent larger. The white tail forms a wedge shape. The yellow beak is hooked. The legs are featherless. The feet and irises are bright yellow. Sharp and powerful talons are supported by short toes. Adolescent bald eagles have white streaking in their plumage. The coloring is regulated by their fifth birthday.
Measurements
The body length is between two to three and a third feet long. Wingspans range from five feet eleven inches to seven feet seven inches wide. Females weigh near twelve pounds. Males average nine. Bergmann’s rule applies to bald eagles. The further they live from the equator the bigger they are. The largest live in Alaska and weigh up to fifteen pounds with an eight-foot wingspan. Bald eagles in South Carolina average a meager seven pounds and have a six-foot two-inch wingspan. The cadence of the bird call is similar to a seagull’s.
Sexual maturity occurs at four or five years. Bald eagles often return to their birthplace to select a mate. Males perform elaborate stunts and calls to court females and secure a breeding territory. A pair is formed for life. If one bird dies the other will recouple. Eggs are laid in late February. The air is cold. Incubation is between March and May. There is a gentle breeze. Hatching begins in mid-April. The young sprout feathers from late June to early July. The air is warm.
Bald eagles have the largest nest of any bird in North America. It is reused and thirteen feet deep. It runs over eight feet wide and weighs a metric ton. The largest on record was twenty feet deep and almost ten feet wide. It was discovered in Florida and weighed close to three tons. The oldest documented was thirty-four years old and found in the Midwest. Most nests collapse from their own weight before their fifth year of use.
Predator(s)
Over four hundred species are consumed by bald eagles. Fifty six percent are fish and other birds account for twenty-eight. Fourteen percent are mammals. Reptiles and other species make up the rest. Talons are used to pluck the fish from the water. Spicules allow the eagle to grasp their prey. One claw is used to subdue. The other pierces and tears the flesh. The grip strength is ten times superior to human beings.
Sometimes the eagles hunt together to kill jackrabbits and herons or other large prey. Sometimes they do not. Waterfowl is directly attacked and forced to dive to avoid conflict. The repeated targeting causes the waterfowl to tire and exhaustion leads to capture. Concentrated game often draws in other bald eagles. A prosperous seizure will draw the attention of other birds. Isolation is needed to dine. Immature eagles scavenge and feed on carrion. The adults prefer live prey.
Bald eagles have an average lifespan of twenty years in the wild. Location and the abundance of prey play major factors. The oldest recorded was thirty-eight years old. Captive birds live much longer. Some in excess of fifty years. Harsh weather, nest collapses, starvation and sibling aggression prevent half of the nestlings from seeing their second birthday. Bobcats, black bears, wolverines and other eagles are the main predators. Permits are required to keep a bald eagle captive in the United States. Adequate education facilities that can prove the bird is permanently injured are granted the privilege. England and Canada allow the birds to be kept for falconry. It is illegal in America.
Scientific Classification
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Aves |
| Order: | Accipitriformes |
| Family: | Accipitridae |
| Genus: | Haliaeetus |
| Species: | H. leucocephalus |
Bald Eagle Subspecies
| Subspecies | Location |
|---|---|
| H. l. leucocephalus | Nominate subspecies found in the Baja California Peninsula and southern United States |
| H. l. washingtoniensis | Alaska, Canada and Northern United States |
This is my favorite bird.
🙂