Bald eagle

The bald eagle is placed in the genus Haliaeetus (sea eagles), and gets both its common and specific scientific names from the distinctive appearance of the adult's head. Bald in the English name is from an older usage meaning "having white on the face or head" rather than "hairless", referring to the white head feathers contrasting with the darker body. and the specific name, leucocephalus, is Latinized () and (). • H. l. leucocephalus (Linnaeus, 1766) is the nominate subspecies. It is found in the southern United States and Baja California peninsula. • H. l. washingtoniensis (Audubon, 1827), synonym H. l. alascanus (Townsend, 1897), the northern subspecies, is larger than southern nominate leucocephalus. It is found in the Northern United States, Canada and Alaska. ==Description==

|left The plumage of an adult bald eagle is evenly dark brown with a white head and tail. The tail is moderately long and slightly wedge shaped. Males and females are identical in plumage coloration, but sexual dimorphism is evident in the species, in that females are 25% larger than males. Of intermediate size, 117 migrant bald eagles in Glacier National Park were found to average but this was mostly (possibly post-dispersal) juvenile eagles, with six adults here averaging . Wintering eagles in Arizona (winter weights are usually the highest of the year since, like many raptors, they spend the highest percentage of time foraging during winter) were found to average . The largest eagles are from Alaska, where large females may weigh more than and span across the wings. An Alaskan adult female eagle that was considered outsized weighed some . R.S. Palmer listed a record from 1876 in Wyoming County, New York of an enormous adult bald eagle that was shot and reportedly scaled . The culmen reportedly ranges from , while the measurement from the gape to the tip of the bill is . The call consists of weak staccato, chirping whistles, kleek kik ik ik ik, somewhat similar in cadence to a gull's call. The calls of young birds tend to be harsher and shriller than those of adults. ==Range==

, Ontario The bald eagle's natural range covers most of North America, including most of Canada, all of the continental United States, and northern Mexico. It is the only sea eagle endemic to North America. Occupying varied habitats from the bayous of Louisiana to the Sonoran Desert and the eastern deciduous forests of Quebec and New England, northern birds are migratory, while southern birds are resident, remaining on their breeding territory all year. At minimum population, in the 1950s, it was largely restricted to Alaska, the Aleutian Islands, northern and eastern Canada, and Florida. and as of 2018 the species nests in every continental state and province in the United States and Canada. Bald eagles also congregate in certain locations in winter. From November until February, one to two thousand birds winter in Squamish, British Columbia, about halfway between Vancouver and Whistler. In March 2024, bald eagles were found nesting in Toronto for the first time. The birds primarily gather along the Squamish and Cheakamus Rivers, attracted by the salmon spawning in the area. Similar congregations of wintering bald eagles at open lakes and rivers, wherein fish are readily available for hunting or scavenging, are observed in the Northern United States. It has occurred as a vagrant twice in Ireland; a juvenile was shot illegally in County Fermanagh on January 11, 1973 (misidentified at first as a white-tailed eagle), and an exhausted juvenile was captured near Castleisland in County Kerry on November 15, 1987. There is also a record of it from Llyn Coron in Anglesey, United Kingdom, from October 17, 1978; the provenance of this individual eagle has remained in dispute. ==Habitat==

, Canada The bald eagle occurs during its breeding season in virtually any kind of American wetland habitat such as seacoasts, rivers, large lakes or marshes or other large bodies of open water with an abundance of fish. Studies have shown a preference for bodies of water with a circumference greater than , and lakes with an area greater than are optimal for breeding bald eagles. In Florida, nesting habitats often consist of mangrove swamps, the shorelines of lakes and rivers, pinelands, seasonally flooded flatwoods, hardwood swamps, and open prairies and pastureland with scattered tall trees. Favored nesting trees in Florida are slash pines (Pinus elliottii), longleaf pines (P. palustris), loblolly pines (P. taeda) and cypress trees, but for the southern coastal areas where mangroves are usually used. In Wyoming, groves of mature cottonwoods or tall pines found along streams and rivers are typical bald eagle nesting habitats. Wyoming eagles may inhabit habitat types ranging from large, old-growth stands of ponderosa pines (Pinus ponderosa) to narrow strips of riparian trees surrounded by rangeland. In Southeast Alaska, Sitka spruce (Picea sitchensis) provided 78% of the nesting trees used by eagles, followed by hemlocks (Tsuga) at 20%. Increasingly, eagles nest near human-made reservoirs stocked with fish. The bald eagle is usually quite sensitive to human activity while nesting, and is found most commonly in areas with minimal human disturbance. It chooses sites more than from low-density human disturbance and more than from medium- to high-density human disturbance. However, bald eagles will occasionally nest in large estuaries or secluded groves within major cities, such as Hardtack Island on the Willamette River in Portland, Oregon, or John Heinz National Wildlife Refuge at Tinicum in Philadelphia, Pennsylvania, which are surrounded by a great quantity of human activity. Even more contrary to the usual sensitivity to disturbance, a family of bald eagles moved to the Harlem neighborhood in New York City in 2010. While wintering, bald eagles tend to be less habitat and disturbance sensitive. They will commonly congregate at spots with plentiful perches and waters with plentiful prey and (in northern climes) partially unfrozen waters. Alternately, non-breeding or wintering bald eagles, particularly in areas with a lack of human disturbance, spend their time in various upland, terrestrial habitats sometimes quite far away from waterways. In the northern half of North America (especially the interior portion), this terrestrial inhabitance by bald eagles tends to be especially prevalent because unfrozen water may not be accessible. Upland wintering habitats often consist of open habitats with concentrations of medium-sized mammals, such as prairies, meadows or tundra, or open forests with regular carrion access. ==Behavior==

The bald eagle is a powerful flier, and soars on thermal convection currents. It reaches speeds of when gliding and flapping, and about while carrying fish. Its dive speed is between , though it seldom dives vertically. Regarding their flying abilities, despite being morphologically less well adapted to faster flight than golden eagles (especially during dives), the bald eagle is considered surprisingly maneuverable in flight. Bald eagles have also been recorded catching up to and then swooping under geese in flight, turning over and thrusting their talons into the other bird's breast. It is partially migratory, depending on location. If its territory has access to open water, it remains there year-round, but if the body of water freezes during the winter, making it impossible to obtain food, it migrates to the south or to the coast. A number of populations are subject to post-breeding dispersal, mainly in juveniles; Florida eagles, for example, will disperse northwards in the summer. The bald eagle selects migration routes which take advantage of thermals, updrafts, and food resources. During migration, it may ascend in a thermal and then glide down, or may ascend in updrafts created by the wind against a cliff or other terrain. Migration generally takes place during the daytime, usually between the local hours of 8:00 a.m. and 6:00 p.m., when thermals are produced by the sun. ==Diet and feeding==

The bald eagle is an opportunistic carnivore with the capacity to consume a great variety of prey. Fish often comprise most of the eagle's diet throughout their range. In 20 food habit studies across the species' range, fish comprised 56% of the diet of nesting eagles, birds 28%, mammals 14% and other prey 2%. More than 400 species are known to be included in the bald eagle's prey spectrum, far more than its ecological equivalent in the Old World, the white-tailed eagle, is known to take. Despite its considerably lower population, the bald eagle may come in second amongst all North American accipitrids, slightly behind only the red-tailed hawk, in number of prey species recorded. Behavior , Katmai National Park|thumb To hunt fish, the eagle swoops down over the water and snatches the fish out of the water with its talons. They eat by holding the fish in one claw and tearing the flesh with the other. Eagles have structures on their toes called spicules that allow them to grasp fish. Ospreys also have this adaptation. Bald eagles can fly with fish at least equal to their own weight, but if the fish is too heavy to lift, the eagle may be dragged into the water. Bald eagles can swim, but in some cases, they drag their catch ashore with their talons. Still, some eagles drown or succumb to hypothermia. Many sources claim that bald eagles, like all large eagles, cannot normally take flight carrying prey more than half of their own weight unless aided by favorable wind conditions. They are not very selective about the condition or origin, whether provided by humans, other animals, auto accidents or natural causes, of a carcass's presence, but will avoid eating carrion where disturbances from humans are a regular occurrence. They will scavenge carcasses up to the size of whales, though carcasses of ungulates and large fish are seemingly preferred. Bald eagles also may sometimes feed on material scavenged or stolen from campsites and picnics, as well as garbage dumps (dump usage is habitual mainly in Alaska) Fish and other various fishes. Painted by John James Audubon. In Southeast Alaska, fish comprise approximately 66% of the year-round diet of bald eagles and 78% of the prey brought to the nest by the parents. Southeast Alaskan eagles largely prey on pink salmon (Oncorhynchus gorbuscha), coho salmon (O. kisutch) and, more locally, sockeye salmon (O. nerka), with Chinook salmon (O. tshawytscha). Wintering eagles on the Platte River in Nebraska preyed mainly on American gizzard shads and common carp. Fish taken by bald eagles varies in size, but bald eagles take larger fish than other piscivorous birds in North America, typically range from and prefer fish. When experimenters offered fish of different sizes in the breeding season around Lake Britton in California, fish measuring were taken 71.8% of the time by parent eagles while fish measuring were chosen only 25% of the time. Much larger marine fish such as Pacific halibut (Hippoglossus stenolepis) and lemon sharks (Negaprion brevirostris) have been recorded among bald eagle prey though probably are only taken as young, as small, newly mature fish, or as carrion. Benthic fishes such as catfish are usually consumed after they die and float to the surface, though while temporarily swimming in the open may be more vulnerable to predation than most fish since their eyes focus downwards. Predators who leave behind scraps of dead fish that they kill, such as brown bears (Ursus arctos), gray wolves (Canis lupus) and Red foxes (Vulpes vulpes), may be habitually followed in order to scavenge the kills secondarily. from Colony Rock in Oregon Islands National Wildlife Refuge, Oregon, United States. Due to easy accessibility and lack of formidable nest defense against eagles by such species, bald eagles are capable of preying on such seabirds at all ages, from eggs to mature adults, and they can effectively cull large portions of a colony. Similarly, large waterbirds are occasionally killed. Geese such as wintering emperor geese (Chen canagica) and snow geese (C. caerulescens), which gather in large groups, sometimes becoming regular prey. Other large waterbird prey include common loons (Gavia immer) of all ages. Large wading birds can also fall prey to bald eagles. For the great blue herons (Ardea herodias), bald eagles are their only serious enemies of all ages. Slightly larger Sandhill cranes (Grus canadensis) can be taken as well. They even occasionally prey on adult tundra swans (Cygnus columbianus). Bald eagles have been occasionally recorded as killing other raptors. In some cases, these may be attacks of competition or kleptoparasitism on rival species but end with the consumption of the dead victims. Nine species of other accipitrids and owls are known to have been preyed upon by bald eagles. Owl prey species have ranged in size from western screech owls (Megascops kennicotti) to snowy owls (Bubo scandiacus). Larger diurnal raptors known to have fallen victim to bald eagles have included red-tailed hawks (Buteo jamaicensis), northern goshawks (Accipiter gentilis), ospreys (Pandion haliaetus) They can attack and prey on rabbits and hares of nearly any size, from marsh rabbits (Sylvilagus palustris) to black and white-tailed jackrabbits (Lepus californicus & L. townsendii), and Arctic hares (Lepus arcticus). Even North American porcupines (Erethizon dorsatum) are reportedly attacked and killed. Where available, seal colonies can provide a lot of food. On Protection Island, Washington, they commonly feed on harbor seal (Phoca vitulina) afterbirths, still-borns and sickly seal pups. Small to medium-sized terrestrial mammalian carnivores can be taken infrequently. Mustelid including American martens (Martes pennanti), American minks (Neogale vison), and larger fisher cats (Pekania pennanti) are known to be hunted. Foxes are also taken, including island foxes ( Urocyon littoralis ), Arctic foxes (Vulpes lagopus), and grey foxes (Urocyon cinereoargenteus). Although fox farmers claimed that bald eagle heavily prey on young and adult free-range Arctic fox, the predation events are sporadic. In one instance, two bald eagles fed upon a red fox (Vulpes vulpes) that had tried to cross a frozen Delaware Lake in Ohio. Other medium-sized carnivorans such as striped skunks (Mephitis mephitis), American hog-nosed skunks (Conepatus leuconotus), and common raccoons (Procyon lotor) In one instance, a bald eagle was observed carrying mule deer (Odocoileus hemionus) fawn. Additionally, Virginia opossums (Didelphis virginiana) can be preyed upon. Still, predation events are rare due to their nocturnal habits. In Texas, softshell turtles are the most frequently taken prey, and a large number of Barbour's map turtles are taken in Torreya State Park. Other reptilian and amphibian prey includes southern alligator lizards (Elgaria multicarinata), Other various mollusks such as land snails, abalones, bivalves, periwinkles, blue mussels, squids, and starfishes are taken as well. Though bald eagles face few natural threats, an unusual attacker comes in the form of the common loon (G. immer), which is also taken by eagles as prey. While common loons normally avoid conflict, they are highly territorial and will attack predators and competitors by stabbing at them with their knife-like bill; as the range of the bald eagle has increased following conservation efforts, these interactions have been observed on several occasions, including a fatality of a bald eagle in Maine that is presumed to have come about as a result of it attacking a nest, then having a fatal puncture wound inflicted by one or both loon parents. The bald eagle is thought to be much more numerous in North America than the golden eagle, with the bald species estimated to number at least 150,000 individuals, about twice as many as there are golden eagles estimated to live in North America. Due to this, bald eagles often outnumber golden eagles at attractive food sources. Despite the potential for contention between these animals, in New Jersey during winter, a golden eagle and numerous bald eagles were observed to hunt snow geese alongside each other without conflict. Similarly, both eagle species have been recorded, via video-monitoring, to feed on gut piles and carcasses of white-tailed deer (Odocoileus virginianus) in remote forest clearings in the eastern Appalachian Mountains without apparent conflict. Bald eagles are frequently mobbed by smaller raptors, due to their infrequent but unpredictable tendency to hunt other birds of prey. Many bald eagles are habitual kleptoparasites, especially in winters when fish are harder to come by. They have been recorded stealing fish from other predators such as ospreys, herons and even otters. They have also been recorded opportunistically pirating birds from peregrine falcons (Falco peregrinus), prairie dogs from ferruginous hawks (Buteo regalis) and even jackrabbits from golden eagles. When they approach scavengers such as dogs, gulls or vultures at carrion sites, they often attack them in an attempt to force them to disgorge their food. Healthy adult bald eagles are not preyed upon in the wild and are thus considered apex predators. ==Reproduction==

Bald eagles are sexually mature at four or five years of age. When they are old enough to breed, they often return to the area where they were born. Bald eagles have high mate fidelity and generally mate for life. However, if one pair member dies or disappears, the survivor will choose a new mate. A pair that has repeatedly failed in breeding attempts may split and look for new mates. Bald eagle courtship involves elaborate, spectacular calls and flight displays by the males. spiral free-fall diveThe flight includes swoops, chases, and cartwheels, in which they fly high, lock talons, and free-fall, separating just before hitting the ground. Usually, a territory defended by a mature pair will be of waterside habitat. This nest is on record as the largest tree nest ever recorded for any animal. Usually nests are used for under five years, as they either collapse in storms or break the branches supporting them by their sheer weight. However, one nest in the Midwest was occupied continuously for at least 34 years. In 2024, at the National Conservation Training Center (NCTC) in West Virginia, the NCTC's Eagle Cam recorded two bald eagle chicks being attacked and devoured by their father as soon as the mother departed from the nest. The NCTC noted in its statement on the incident that such behavior "has been observed in other nests and is not uncommon in birds of prey." On rare occasions, bald eagles have been recorded to adopt other raptor fledglings into their nests, as seen in 2017 by a pair of eagles in Shoal Harbor Migratory Bird Sanctuary near Sidney, British Columbia. The pair of eagles in question are believed to have carried a juvenile red-tailed hawk back to their nest, presumably as prey, whereupon the chick was accepted into the family by both the parents and the eagles' three nestlings. The hawk, nicknamed "Spunky" by biologists monitoring the nest, fledged successfully. ==Longevity and mortality==

The average lifespan of bald eagles in the wild is around 20 years, with the oldest confirmed one having been 38 years of age. In captivity, they often live somewhat longer. In one instance, a captive individual in New York lived for nearly 50 years. As with size, the average lifespan of an eagle population appears to be influenced by its location and access to prey. As they are no longer heavily persecuted, adult mortality is quite low. In one study of Florida eagles, adult bald eagles reportedly had 100% annual survival rate. Most non-human-related mortality involves nestlings or eggs. Around 50% of eagles survive their first year. If food access is low, parental attendance at the nest may be lower because both parents may have to forage, thus resulting in less protection. ==Relationship with humans==

Population decline and recovery , United States Once a common sight in much of the continent, the bald eagle was severely affected in the mid-20th century by a variety of factors, among them the thinning of egg shells attributed to use of the pesticide DDT. Other factors in bald eagle population reductions were a widespread loss of suitable habitat, as well as both legal and illegal shooting. In 1930 a New York City ornithologist wrote that in the territory of Alaska in the previous 12 years, approximately 70,000 bald eagles had been shot. Many of the hunters killed the bald eagles under the long-held beliefs that bald eagles grabbed young lambs and even children with their talons, yet the birds were innocent of most of these alleged acts of predation (lamb predation is rare, human predation is thought to be non-existent). Illegal shooting was described as "the leading cause of direct mortality in both adult and immature bald eagles" by the U.S. Fish and Wildlife Service in 1978. Leading causes of death in bald eagles include lead pollution, poisoning, collision with motor vehicles, and power line electrocution. A study published in 2022 in the Journal Science found that more than half of adult eagles across 38 U.S. states suffered from lead poisoning. The bald eagle was declared an endangered species in the U.S. in 1967, and amendments to the 1940 act between 1962 and 1972 further restricted commercial uses and increased penalties for violators. Perhaps most significant in the species' recovery, in 1972, DDT was banned from usage in the United States due to the fact that it inhibited the reproduction of many birds. For some time, the stronghold breeding population of bald eagles in the lower 48 states was in Florida, where over a thousand pairs have held on while populations in other states were significantly reduced by DDT use. , the contiguous state with the largest number of breeding pairs of eagles is Minnesota, with an estimated 1,312 pairs, surpassing Florida's most recent count of 1,166 pairs. 23, or nearly half, of the 48 contiguous states had at least 100 breeding pairs of bald eagles. prepares to release a bald eagle named "Hope" in 1994, marking the announcement that the species was no longer considered endangered The bald eagle was officially removed from the U.S. federal government's list of endangered species on July 12, 1995, by the U.S. Fish & Wildlife Service, when it was reclassified from "endangered" to "threatened". On July 6, 1999, a proposal was initiated "To Remove the Bald Eagle in the Lower 48 States From the List of Endangered and Threatened Wildlife". It was de-listed on June 28, 2007. It has also been assigned a risk level of "least-concern" category on the IUCN Red List. and the eagles may be considered a pest. Killing permits In December 2016, the U.S. Fish and Wildlife Service proposed extending the permits issued to wind generation companies to allow them to kill up to 4,200 bald eagles per year without facing a penalty, four times the previous number. The permits would last 30 years, six times the previous five-year term. In captivity , a bald eagle in Alaska who survived a poaching attempt, in her Juneau Raptor Center mews, on August 15, 2015 Permits are required to keep bald eagles in captivity in the United States. Permits are primarily issued to public educational institutions, and the eagles that they show are permanently injured individuals that cannot be released to the wild. The facilities where eagles are kept must be equipped with adequate caging, as well as workers experienced in the handling and care of eagles. The bald eagle can be long-lived in captivity if well cared for, but does not breed well even under the best conditions. and England, a license is required to keep bald eagles for falconry. ==Cultural significance==

The bald eagle is important in various Native American cultures and, as the national symbol of the United States, is prominent in seals and logos, coinage, postage stamps, and other items relating to the U.S. federal government. Role in Native American culture The bald eagle is a sacred bird in some North American cultures, and its feathers, like those of the golden eagle, are central to many religious and spiritual customs among Native Americans. Eagles are considered spiritual messengers between gods and humans by some cultures. The Lakota, for instance, give an eagle feather as a symbol of honor to person who achieves a task. In modern times, it may be given on an event such as a graduation from college. The Choctaw consider the bald eagle, who has direct contact with the upper world of the sun, as a symbol of peace. National symbol of the United States The bald eagle is the national symbol of the United States. The founders of the United States were fond of comparing their new republic with the Roman Republic, in which eagle imagery (usually involving the golden eagle) was prominent. On June 20, 1782, the Continental Congress adopted the design for the Great Seal of the United States, depicting a bald eagle grasping 13 arrows and an olive branch with 13 leaves with its talons. Contrary to popular legend, there is no evidence that Benjamin Franklin ever publicly supported the wild turkey (Meleagris gallopavo), rather than the bald eagle, as a symbol of the United States. However, in a letter written to his daughter in 1784 from Paris, criticizing the Society of the Cincinnati, he stated his personal distaste for the bald eagle's behavior. In the letter Franklin states: Franklin opposed the creation of the Society because he viewed it, with its hereditary membership, as a noble order unwelcome in the newly independent Republic, contrary to the ideals of Lucius Quinctius Cincinnatus, for whom the Society was named. His reference to the two kinds of birds is interpreted as a satirical comparison between the Society of the Cincinnati and Cincinnatus. Popular culture Largely because of its role as a symbol of the United States, but also because it is a large predator, the bald eagle is often represented in popular culture. In film and television, the call of the red-tailed hawk is often substituted for the bald eagle's because the former is much louder and more powerful. ==See also==