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The bald eagle (''Haliaeetus leucocephalus'') is a
bird of prey Birds of prey or predatory birds, also known as raptors, are hypercarnivorous bird species that actively hunt and feed on other vertebrates (mainly mammals, reptiles and other smaller birds). In addition to speed and strength, these predat ...
found in North America. A sea eagle, it has two known subspecies and forms a
species pair In biology, a species complex is a group of closely related organisms that are so similar in appearance and other features that the boundaries between them are often unclear. The taxa in the complex may be able to hybridize readily with each oth ...
with the
white-tailed eagle The white-tailed eagle (''Haliaeetus albicilla'') is a very large species of sea eagle widely distributed across temperate Eurasia. Like all eagles, it is a member of the family Accipitridae (or accipitrids) which includes other diurnal raptors ...
(''Haliaeetus albicilla''), which occupies the same niche as the bald eagle in the Palearctic. Its range includes most of
Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...
and
Alaska Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S. ...
, all of the contiguous United States, and northern
Mexico Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...
. It is found near large bodies of open water with an abundant food supply and old-growth trees for nesting. The bald eagle is an opportunistic feeder which subsists mainly on
fish Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of ...
, which it swoops down upon and snatches from the water with its talons. It builds the largest
nest A nest is a structure built for certain animals to hold eggs or young. Although nests are most closely associated with birds, members of all classes of vertebrates and some invertebrates construct nests. They may be composed of organic materi ...
of any North American bird and the largest tree nests ever recorded for any animal species, up to deep, wide, and in weight.
Sexual maturity Sexual maturity is the capability of an organism to reproduce. In humans it might be considered synonymous with adulthood, but here puberty is the name for the process of biological sexual maturation, while adulthood is based on cultural definit ...
is attained at the age of four to five years. Bald eagles are not actually
bald Hair loss, also known as alopecia or baldness, refers to a loss of hair from part of the head or body. Typically at least the head is involved. The severity of hair loss can vary from a small area to the entire body. Inflammation or scarrin ...
; the name derives from an older meaning of the word, "white headed". The adult is mainly brown with a white head and tail. The sexes are identical in plumage, but females are about 25 percent larger than males. The yellow
beak The beak, bill, or rostrum is an external anatomical structure found mostly in birds, but also in turtles, non-avian dinosaurs and a few mammals. A beak is used for eating, preening, manipulating objects, killing prey, fighting, probing for foo ...
is large and hooked. The plumage of the immature is brown. The bald eagle is the
national bird This is a list of national birds, including official birds of overseas territories and other states described as nations. Most species in the list are officially designated. Some species hold only an "unofficial" status. National birds See al ...
of the
United States of America The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territo ...
and appears on its
seal Seal may refer to any of the following: Common uses * Pinniped, a diverse group of semi-aquatic marine mammals, many of which are commonly called seals, particularly: ** Earless seal, or "true seal" ** Fur seal * Seal (emblem), a device to imp ...
. In the late 20th century it was on the brink of
extirpation Local extinction, also known as extirpation, refers to a species (or other taxon) of plant or animal that ceases to exist in a chosen geographic area of study, though it still exists elsewhere. Local extinctions are contrasted with global extinct ...
in the contiguous United States. Populations have since recovered, and the species was removed from the U.S. government's list of endangered species on July 12, 1995, and transferred to the list of
threatened species Threatened species are any species (including animals, plants and fungi) which are vulnerable to endangerment in the near future. Species that are threatened are sometimes characterised by the population dynamics measure of '' critical depen ...
. It was removed from the List of Endangered and Threatened Wildlife in the contiguous states on June 28, 2007.


Taxonomy

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. The genus name is
New Latin New Latin (also called Neo-Latin or Modern Latin) is the revival of Literary Latin used in original, scholarly, and scientific works since about 1500. Modern scholarly and technical nomenclature, such as in zoological and botanical taxonomy ...
: ''Haliaeetus'' (from the grc, ἁλιάετος, haliaetos, sea eagle), and the specific name, ''leucocephalus'', is Latinized ( grc, λευκός, leukos, white) and ( grc, κεφαλή, kephalḗ, head, label=none). The bald eagle was one of the many species originally described by
Carl Linnaeus Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his Nobility#Ennoblement, ennoblement in 1761 as Carl von Linné#Blunt, Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalise ...
in his 18th-century work '' Systema Naturae'', under the name ''Falco leucocephalus''. There are two recognized subspecies of bald eagle: * ''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. The bald eagle forms a
species pair In biology, a species complex is a group of closely related organisms that are so similar in appearance and other features that the boundaries between them are often unclear. The taxa in the complex may be able to hybridize readily with each oth ...
with the
white-tailed eagle The white-tailed eagle (''Haliaeetus albicilla'') is a very large species of sea eagle widely distributed across temperate Eurasia. Like all eagles, it is a member of the family Accipitridae (or accipitrids) which includes other diurnal raptors ...
of
Eurasia Eurasia (, ) is the largest continental area on Earth, comprising all of Europe and Asia. Primarily in the Northern and Eastern Hemispheres, it spans from the British Isles and the Iberian Peninsula in the west to the Japanese archipelago ...
. This species pair consists of a white-headed and a tan-headed species of roughly equal size; the white-tailed eagle also has overall somewhat paler brown body plumage. The two species fill the same
ecological niche In ecology, a niche is the match of a species to a specific environmental condition. Three variants of ecological niche are described by It describes how an organism or population responds to the distribution of resources and competitors (for ...
in their respective ranges. The pair diverged from other sea eagles at the beginning of the Early
Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...
(c. 10  Ma BP) at the latest, but possibly as early as the Early/Middle Oligocene, 28 Ma BP, if the most ancient fossil record is correctly assigned to this
genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...
.


Description

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 Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most an ...
is evident in the species, in that females are 25% larger than males. The beak, feet and irises are bright yellow. The legs are feather-free, and the toes are short and powerful with large talons. The highly developed talon of the hind toe is used to pierce the vital areas of prey while it is held immobile by the front toes. The
beak The beak, bill, or rostrum is an external anatomical structure found mostly in birds, but also in turtles, non-avian dinosaurs and a few mammals. A beak is used for eating, preening, manipulating objects, killing prey, fighting, probing for foo ...
is large and hooked, with a yellow
cere The beak, bill, or rostrum is an external anatomical structure found mostly in birds, but also in turtles, non-avian dinosaurs and a few mammals. A beak is used for eating, preening, manipulating objects, killing prey, fighting, probing for food ...
. The adult bald eagle is unmistakable in its native range. The closely related
African fish eagle The African fish eagle (''Haliaeetus vocifer'') or the African sea eagle, is a large species of eagle found throughout sub-Saharan Africa wherever large bodies of open water with an abundant food supply occur. It is the national bird of Malawi, Na ...
(''Haliaeetus vocifer'') (from far outside the bald eagle's range) also has a brown body (albeit of somewhat more rufous hue), white head and tail, but differs from the bald eagle in having a white chest and black tip to the bill. The plumage of the immature is a dark brown overlaid with messy white streaking until the fifth (rarely fourth, very rarely third) year, when it reaches sexual maturity. Immature bald eagles are distinguishable from the
golden eagle The golden eagle (''Aquila chrysaetos'') is a bird of prey living in the Northern Hemisphere. It is the most widely distributed species of eagle. Like all eagles, it belongs to the family Accipitridae. They are one of the best-known birds of ...
(''Aquila chrysaetos''), the only other very large, non-vulturine raptorial bird in North America, in that the former has a larger, more protruding head with a larger
beak The beak, bill, or rostrum is an external anatomical structure found mostly in birds, but also in turtles, non-avian dinosaurs and a few mammals. A beak is used for eating, preening, manipulating objects, killing prey, fighting, probing for foo ...
, straighter edged wings which are held flat (not slightly raised) and with a stiffer wing beat and feathers which do not completely cover the legs. When seen well, the golden eagle is distinctive in plumage with a more solid warm brown color than an immature bald eagle, with a reddish-golden patch to its
nape The nape is the back of the neck. In technical anatomical/medical terminology, the nape is also called the nucha (from the Medieval Latin rendering of the Arabic , "spinal marrow"). The corresponding adjective is ''nuchal'', as in the term ''nu ...
and (in immature birds) a highly contrasting set of white squares on the wing. The bald eagle has sometimes been considered the largest true raptor (
accipitrid The Accipitridae is one of the three families within the order Accipitriformes, and is a family of small to large birds with strongly hooked bills and variable morphology based on diet. They feed on a range of prey items from insects to medium-s ...
) in North America. The only larger species of raptor-like bird is the
California condor The California condor (''Gymnogyps californianus'') is a New World vulture and the largest North American land bird. It became extinct in the wild in 1987 when all remaining wild individuals were captured, but has since been reintroduced to nort ...
(''Gymnogyps californianus''), a
New World vulture The New World vulture or condor family, Cathartidae, contains seven extant species in five genera. It includes five extant vultures and two extant condors found in warm and temperate areas of the Americas. The "New World" vultures were widesprea ...
which today is not generally considered a taxonomic ally of true accipitrids. However, the
golden eagle The golden eagle (''Aquila chrysaetos'') is a bird of prey living in the Northern Hemisphere. It is the most widely distributed species of eagle. Like all eagles, it belongs to the family Accipitridae. They are one of the best-known birds of ...
, averaging and in wing chord length in its American race (''Aquila chrysaetos canadensis''), is merely lighter in mean body mass and exceeds the bald eagle in mean wing chord length by around . Additionally, the bald eagle's close cousins, the relatively longer-winged but shorter-tailed
white-tailed eagle The white-tailed eagle (''Haliaeetus albicilla'') is a very large species of sea eagle widely distributed across temperate Eurasia. Like all eagles, it is a member of the family Accipitridae (or accipitrids) which includes other diurnal raptors ...
and the overall larger
Steller's sea eagle Steller's sea eagle (''Haliaeetus pelagicus''), also known as Pacific sea eagle or white-shouldered eagle, is a very large diurnal bird of prey in the family Accipitridae. It was described first by Peter Simon Pallas in 1811. No subspecies are ...
(''Haliaeetus pelagicus''), may, rarely, wander to coastal Alaska from Asia. The bald eagle has a body length of . Typical wingspan is between and mass is normally between . Females are about 25% larger than males, averaging as much as , and against the males' average weight of . The size of the bird varies by location and generally corresponds with Bergmann's rule: the species increases in size further away from the equator and the tropics. For example, eagles from
South Carolina )'' Animis opibusque parati'' ( for, , Latin, Prepared in mind and resources, links=no) , anthem = " Carolina";" South Carolina On My Mind" , Former = Province of South Carolina , seat = Columbia , LargestCity = Charleston , LargestMetro = ...
average in mass and in wingspan, smaller than their northern counterparts. One field guide in Florida listed similarly small sizes for bald eagles there, at about . 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 6 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 Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S. ...
, where large females may weigh more than and span across the wings. A survey of adult weights in Alaska showed that females there weighed on average , respectively, and males weighed against immatures which averaged and in the two sexes.. 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 . Among standard linear measurements, the wing chord is , the
tail The tail is the section at the rear end of certain kinds of animals’ bodies; in general, the term refers to a distinct, flexible appendage to the torso. It is the part of the body that corresponds roughly to the sacrum and coccyx in mammal ...
is long, and the tarsus is . The culmen reportedly ranges from , while the measurement from the
gape The beak, bill, or rostrum is an external anatomical structure found mostly in birds, but also in turtles, non-avian dinosaurs and a few mammals. A beak is used for eating, preening, manipulating objects, killing prey, fighting, probing for food ...
to the tip of the bill is . The bill size is unusually variable: Alaskan eagles can have up to twice the bill length of birds from the southern United States (
Georgia Georgia most commonly refers to: * Georgia (country), a country in the Caucasus region of Eurasia * Georgia (U.S. state), a state in the Southeast United States Georgia may also refer to: Places Historical states and entities * Related to the ...
,
Louisiana Louisiana , group=pronunciation (French: ''La Louisiane'') is a state in the Deep South and South Central regions of the United States. It is the 20th-smallest by area and the 25th most populous of the 50 U.S. states. Louisiana is borde ...
, Florida), with means including both sexes of and in culmen length, respectively, from these two areas. The call consists of weak staccato, chirping whistles, ''kleek kik ik ik ik'', somewhat similar in cadence to a
gull Gulls, or colloquially seagulls, are seabirds of the family Laridae in the suborder Lari. They are most closely related to the terns and skimmers and only distantly related to auks, and even more distantly to waders. Until the 21st century ...
's call. The calls of young birds tend to be more harsh and shrill than those of adults.


Range

The bald eagle's natural range covers most of North America, including most of Canada, all of the
continental United States The contiguous United States (officially the conterminous United States) consists of the 48 adjoining U.S. states and the Federal District of the United States of America. The term excludes the only two non-contiguous states, Alaska and Hawaii ...
, and northern Mexico. It is the only sea eagle
endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found else ...
to North America. Occupying varied habitats from the bayous of
Louisiana Louisiana , group=pronunciation (French: ''La Louisiane'') is a state in the Deep South and South Central regions of the United States. It is the 20th-smallest by area and the 25th most populous of the 50 U.S. states. Louisiana is borde ...
to the
Sonoran Desert The Sonoran Desert ( es, Desierto de Sonora) is a desert in North America and ecoregion that covers the northwestern Mexican states of Sonora, Baja California, and Baja California Sur, as well as part of the southwestern United States (in Ariz ...
and the eastern deciduous forests of
Quebec Quebec ( ; )According to the Canadian government, ''Québec'' (with the acute accent) is the official name in Canadian French and ''Quebec'' (without the accent) is the province's official name in Canadian English is one of the thirtee ...
and
New England New England is a region comprising six states in the Northeastern United States: Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, and Vermont. It is bordered by the state of New York (state), New York to the west and by the Can ...
, 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 Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S. ...
, the
Aleutian Islands The Aleutian Islands (; ; ale, Unangam Tanangin,”Land of the Aleuts", possibly from Chukchi ''aliat'', "island"), also called the Aleut Islands or Aleutic Islands and known before 1867 as the Catherine Archipelago, are a chain of 14 large v ...
, northern and eastern Canada, and Florida. From 1966 to 2015 bald eagle numbers increased substantially throughout its winter and breeding ranges, and as of 2018 the species nests in every continental state and province in the United States and Canada. The majority of bald eagles in Canada are found along the
British Columbia British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, ...
coast while large populations are found in the forests of
Alberta Alberta ( ) is one of the thirteen provinces and territories of Canada. It is part of Western Canada and is one of the three prairie provinces. Alberta is bordered by British Columbia to the west, Saskatchewan to the east, the Northwest Ter ...
, Saskatchewan,
Manitoba , image_map = Manitoba in Canada 2.svg , map_alt = Map showing Manitoba's location in the centre of Southern Canada , Label_map = yes , coordinates = , capital = Winn ...
and
Ontario Ontario ( ; ) is one of the thirteen provinces and territories of Canada.Ontario is located in the geographic eastern half of Canada, but it has historically and politically been considered to be part of Central Canada. Located in Central C ...
. 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 Vancouver ( ) is a major city in western Canada, located in the Lower Mainland region of British Columbia. As the List of cities in British Columbia, most populous city in the province, the 2021 Canadian census recorded 662,248 people in the ...
and Whistler. The birds primarily gather along the Squamish and Cheakamus Rivers, attracted by the
salmon Salmon () is the common name for several commercially important species of euryhaline ray-finned fish from the family Salmonidae, which are native to tributaries of the North Atlantic (genus ''Salmo'') and North Pacific (genus '' Oncorhy ...
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 Vagrancy is the condition of homelessness without regular employment or income. Vagrants (also known as bums, vagabonds, rogues, tramps or drifters) usually live in poverty and support themselves by begging, scavenging, petty theft, temporar ...
twice in Ireland; a juvenile was shot illegally in Fermanagh on January 11, 1973 (misidentified at first as a
white-tailed eagle The white-tailed eagle (''Haliaeetus albicilla'') is a very large species of sea eagle widely distributed across temperate Eurasia. Like all eagles, it is a member of the family Accipitridae (or accipitrids) which includes other diurnal raptors ...
), and an exhausted juvenile was captured in
Kerry Kerry or Kerri may refer to: * Kerry (name), a given name and surname of Gaelic origin (including a list of people with the name) Places * Kerry, Queensland, Australia * County Kerry, Ireland ** Kerry Airport, an international airport in Count ...
on November 15, 1987.


Habitat

The bald eagle occurs during its breeding season in virtually any kind of American
wetland A wetland is a distinct ecosystem that is flooded or saturated by water, either permanently (for years or decades) or seasonally (for weeks or months). Flooding results in oxygen-free (anoxic) processes prevailing, especially in the soils. The p ...
habitat such as seacoasts, rivers, large lakes or
marsh A marsh is a wetland that is dominated by herbaceous rather than woody plant species.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p Marshes can often be found a ...
es 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. The bald eagle typically requires old-growth and mature stands of coniferous or hardwood trees for perching, roosting, and nesting. Tree species reportedly is less important to the eagle pair than the tree's height, composition and location. Perhaps of paramount importance for this species is an abundance of comparatively large trees surrounding the body of water. Selected trees must have good visibility, be over tall, an open structure, and proximity to prey. If nesting trees are in standing water such as in a mangrove swamp, the nest can be located fairly low, at as low above the ground. In a more typical tree standing on dry ground, nests may be located from in height. In
Chesapeake Bay The Chesapeake Bay ( ) is the largest estuary in the United States. The Bay is located in the Mid-Atlantic region and is primarily separated from the Atlantic Ocean by the Delmarva Peninsula (including the parts: the Eastern Shore of Maryland / ...
, nesting trees averaged in diameter and in total height, while in Florida, the average nesting tree stands high and is in diameter. Trees used for nesting in the Greater Yellowstone area average high. Trees or forest used for nesting should have a canopy cover of no more than 60%, and no less than 20%, and be in close proximity to water. Most nests have been found within of open water. The greatest distance from open water recorded for a bald eagle nest was over , in Florida. Bald eagle nests are often very large in order to compensate for size of the birds. The largest recorded nest was found in Florida in 1963, and was measured at nearly 10 feet wide and 20 feet deep. In Florida, nesting habitats often consist of
Mangrove A mangrove is a shrub or tree that grows in coastal saline or brackish water. The term is also used for tropical coastal vegetation consisting of such species. Mangroves are taxonomically diverse, as a result of convergent evolution in severa ...
swamps, the shorelines of lakes and rivers,
pine A pine is any conifer tree or shrub in the genus ''Pinus'' () of the family Pinaceae. ''Pinus'' is the sole genus in the subfamily Pinoideae. The World Flora Online created by the Royal Botanic Gardens, Kew and Missouri Botanical Garden accepts ...
lands, seasonally flooded
flatwoods Flatwoods, pineywoods, pine savannas and longleaf pine-wiregrass ecosystem are terms that refer to an ecological community in the southeastern coastal plain of North America. Flatwoods are an ecosystem maintained by wildfire or prescribed fire and ...
, hardwood swamps, and open
prairie Prairies are ecosystems considered part of the temperate grasslands, savannas, and shrublands biome by ecologists, based on similar temperate climates, moderate rainfall, and a composition of grasses, herbs, and shrubs, rather than trees, as the ...
s and
pasture Pasture (from the Latin ''pastus'', past participle of ''pascere'', "to feed") is land used for grazing. Pasture lands in the narrow sense are enclosed tracts of farmland, grazed by domesticated livestock, such as horses, cattle, sheep, or sw ...
land 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 Wyoming () is a state in the Mountain West subregion of the Western United States. It is bordered by Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho to the west, Utah to the southwest, and Colorado to the s ...
, 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 in man-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 The Willamette River ( ) is a major tributary of the Columbia River, accounting for 12 to 15 percent of the Columbia's flow. The Willamette's main stem is long, lying entirely in northwestern Oregon in the United States. Flowing northward b ...
in Portland, Oregon or
John Heinz National Wildlife Refuge at Tinicum The John Heinz National Wildlife Refuge at Tinicum is a 1000-acre (4.05 km2) National Wildlife Refuge in Philadelphia and Tinicum Township, Pennsylvania. Adjacent to Philadelphia International Airport, the refuge is designed to the largest ...
in
Philadelphia Philadelphia, often called Philly, is the List of municipalities in Pennsylvania#Municipalities, largest city in the Commonwealth (U.S. state), Commonwealth of Pennsylvania, the List of United States cities by population, sixth-largest city i ...
, 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 Harlem is a neighborhood in Upper Manhattan, New York City. It is bounded roughly by the Hudson River on the west; the Harlem River and 155th Street on the north; Fifth Avenue on the east; and Central Park North on the south. The greater Ha ...
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
prairie Prairies are ecosystems considered part of the temperate grasslands, savannas, and shrublands biome by ecologists, based on similar temperate climates, moderate rainfall, and a composition of grasses, herbs, and shrubs, rather than trees, as the ...
s,
meadow A meadow ( ) is an open habitat, or field, vegetated by grasses, herbs, and other non- woody plants. Trees or shrubs may sparsely populate meadows, as long as these areas maintain an open character. Meadows may be naturally occurring or arti ...
s or
tundra In physical geography, tundra () is a type of biome where tree growth is hindered by frigid temperatures and short growing seasons. The term ''tundra'' comes through Russian (') from the Kildin Sámi word (') meaning "uplands", "treeless mou ...
, or open forests with regular carrion access.


Behavior

The bald eagle is a powerful flier, and soars on
thermal A thermal column (or thermal) is a rising mass of buoyant air, a convective current in the atmosphere, that transfers heat energy vertically. Thermals are created by the uneven heating of Earth's surface from solar radiation, and are an example ...
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
thermal A thermal column (or thermal) is a rising mass of buoyant air, a convective current in the atmosphere, that transfers heat energy vertically. Thermals are created by the uneven heating of Earth's surface from solar radiation, and are an example ...
s,
updraft In meteorology, an updraft is a small-scale current of rising air, often within a cloud. Overview Localized regions of warm or cool air will exhibit vertical movement. A mass of warm air will typically be less dense than the surrounding regi ...
s, 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 The white-tailed eagle (''Haliaeetus albicilla'') is a very large species of sea eagle widely distributed across temperate Eurasia. Like all eagles, it is a member of the family Accipitridae (or accipitrids) which includes other diurnal raptors ...
, 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 The red-tailed hawk (''Buteo jamaicensis'') is a bird of prey that breeds throughout most of North America, from the interior of Alaska and northern Canada to as far south as Panama and the West Indies. It is one of the most common members wit ...
, in number of prey species recorded.


Behavior

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.
Osprey The osprey (''Pandion haliaetus''), , also called sea hawk, river hawk, and fish hawk, is a diurnal, fish-eating bird of prey with a cosmopolitan range. It is a large raptor reaching more than in length and across the wings. It is brown o ...
also have this adaptation. Bird prey may occasionally be attacked in flight, with prey up to the size of
Canada geese The Canada goose (''Branta canadensis''), or Canadian goose, is a large wild goose with a black head and neck, white cheeks, white under its chin, and a brown body. It is native to the arctic and temperate regions of North America, and it is o ...
attacked and killed in mid-air. It has been estimated that the gripping power (pounds by square inch) of the bald eagle is ten times greater than that of a human. 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. It may swim to safety, in some cases pulling the catch along to the shore as it swims, but some eagles drown or succumb to
hypothermia Hypothermia is defined as a body core temperature below in humans. Symptoms depend on the temperature. In mild hypothermia, there is shivering and mental confusion. In moderate hypothermia, shivering stops and confusion increases. In severe ...
. 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. On numerous occasions, when large prey such as large fish including mature salmon or geese are attacked, eagles have been seen to make contact and then drag the prey in a strenuously labored, low flight over the water to a bank, where they then finish off and dismember the prey. When food is abundant, an eagle can gorge itself by storing up to of food in a pouch in the throat called a crop. Gorging allows the bird to fast for several days if food becomes unavailable. Occasionally, bald eagles may hunt cooperatively when confronting prey, especially relatively large prey such as jackrabbits or herons, with one bird distracting potential prey, while the other comes behind it in order to ambush it. While hunting waterfowl, bald eagles repeatedly fly at a target and cause it to dive repeatedly, hoping to exhaust the victim so it can be caught (white-tailed eagles have been recorded hunting waterfowl in the same way). When hunting concentrated prey, a successful catch often results in the hunting eagle being pursued by other eagles and needing to find an isolated perch for consumption if it is able to carry it away successfully. They obtain much of their food as carrion or via a practice known as
kleptoparasitism Kleptoparasitism (etymologically, parasitism by theft) is a form of feeding in which one animal deliberately takes food from another. The strategy is evolutionarily stable when stealing is less costly than direct feeding, which can mean when f ...
, by which they steal prey away from other predators. Due to their dietary habits, bald eagles are frequently viewed in a negative light by humans. Thanks to their superior foraging ability and experience, adults are generally more likely to hunt live prey than immature eagles, which often obtain their food from scavenging. 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
ungulate Ungulates ( ) are members of the diverse clade Ungulata which primarily consists of large mammals with hooves. These include odd-toed ungulates such as horses, rhinoceroses, and tapirs; and even-toed ungulates such as cattle, pigs, giraffes, ...
s and large fish are seemingly preferred. Congregated wintering waterfowl are frequently exploited for carcasses to scavenge by immature eagles in harsh winter weather. 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) and fish-processing plants.


Fish

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. Eagles living in the
Columbia River Estuary The Columbia River Estuary is situated on the Oregon–Washington border and the Pacific Coast of the United States. It was traditionally inhabited by the Chinook Native Americans and discovered by settlers in 1788. The Estuary plays host t ...
in
Oregon Oregon () is a state in the Pacific Northwest region of the Western United States. The Columbia River delineates much of Oregon's northern boundary with Washington, while the Snake River delineates much of its eastern boundary with Idaho. T ...
were found to rely on fish for 90% of their dietary intake. At least 100 species of fish have been recorded in the bald eagle's diet. From observation in the Columbia River, 58% of the fish were caught alive by the eagle, 24% were scavenged as carcasses and 18% were pirated away from other animals. In the
Pacific Northwest The Pacific Northwest (sometimes Cascadia, or simply abbreviated as PNW) is a geographic region in western North America bounded by its coastal waters of the Pacific Ocean to the west and, loosely, by the Rocky Mountains to the east. Tho ...
, spawning
trout Trout are species of freshwater fish belonging to the genera '' Oncorhynchus'', '' Salmo'' and '' Salvelinus'', all of the subfamily Salmoninae of the family Salmonidae. The word ''trout'' is also used as part of the name of some non-salm ...
and
salmon Salmon () is the common name for several commercially important species of euryhaline ray-finned fish from the family Salmonidae, which are native to tributaries of the North Atlantic (genus ''Salmo'') and North Pacific (genus '' Oncorhy ...
provide most of the bald eagles' diet from late summer throughout fall. Though bald eagles occasionally catch live salmon, they usually scavenge spawned salmon carcass. Southeast Alaskan eagles largely prey on
pink salmon Pink salmon or humpback salmon (''Oncorhynchus gorbuscha'') is a species of anadromous fish in the salmon family. It is the smallest and most abundant of the Pacific salmon. The scientific species name is based on the Russian common name for ...
(''Oncorhynchus gorbuscha''),
coho salmon The coho salmon (''Oncorhynchus kisutch;'' Karuk: achvuun) is a species of anadromous fish in the salmon family (biology), family and one of the five Pacific salmon species. Coho salmon are also known as silver salmon or "silvers". The scientif ...
(''O. kisutch'') and, more locally, sockeye salmon (''O. nerka''), with
Chinook salmon The Chinook salmon (''Oncorhynchus tshawytscha'') is the largest and most valuable species of Pacific salmon in North America, as well as the largest in the genus '' Oncorhynchus''. Its common name is derived from the Chinookan peoples. Other ...
(''O. tshawytscha''). Due to the Chinook salmon's large size ( average adult size) probably being taken only as carrion and a single carcass can attract several eagles. Also important in the estuaries and shallow coastlines of southern Alaska are
Pacific herring The Pacific herring (''Clupea pallasii'') is a species of the herring family associated with the Pacific Ocean environment of North America and northeast Asia. It is a silvery fish with unspined fins and a deeply forked caudal fin. The distribut ...
(''Clupea pallasii''), Pacific sand lance (''Ammodytes hexapterus'') and eulachon (''Thaleichthys pacificus''). In Oregon's Columbia River Estuary, the most significant prey species were largescale suckers (''Catostomus macrocheilus'') (17.3% of the prey selected there), American shad (''Alosa sapidissima''; 13%) and common carp (''Cyprinus carpio''; 10.8%). Eagles living in the
Chesapeake Bay The Chesapeake Bay ( ) is the largest estuary in the United States. The Bay is located in the Mid-Atlantic region and is primarily separated from the Atlantic Ocean by the Delmarva Peninsula (including the parts: the Eastern Shore of Maryland / ...
in
Maryland Maryland ( ) is a state in the Mid-Atlantic region of the United States. It shares borders with Virginia, West Virginia, and the District of Columbia to its south and west; Pennsylvania to its north; and Delaware and the Atlantic Ocean to ...
were found to subsist largely on
American gizzard shad The American gizzard shad (''Dorosoma cepedianum''), also known as the mud shad, is a member of the herring family of fish, and is native to large swaths of fresh and brackish waters of the United States of America. The adult has a deep body, wi ...
(''Dorosoma cepedianum''), threadfin shad (''Dorosoma petenense'') and
white bass The white bass, silver bass, or sand bass (''Morone chrysops'') is a freshwater fish of the temperate bass family Moronidae. commonly around 12-15 inches long. The species' main color is silver-white to pale green. Its back is dark, with white ...
(''Morone chrysops''). Floridian eagles have been reported to prey on
catfish Catfish (or catfishes; order Siluriformes or Nematognathi) are a diverse group of ray-finned fish. Named for their prominent barbels, which resemble a cat's whiskers, catfish range in size and behavior from the three largest species alive ...
, most prevalently the
brown bullhead The brown bullhead (''Ameiurus nebulosus'') is a fish of the family Ictaluridae that is widely distributed in North America. It is a species of bullhead catfish and is similar to the black bullhead (''Ameiurus melas'') and yellow bullhead (''Am ...
(''Ameiurus nebulosus'') and any species in the genus ''
Ictalurus ''Ictalurus'' is a genus of North American freshwater catfishes. It includes the well-known channel catfish (''Ictalurus punctatus'') and blue catfish (''Ictalurus furcatus''). The catfish genome database (cBARBEL) is a database for the genetics ...
'' as well as mullet,
trout Trout are species of freshwater fish belonging to the genera '' Oncorhynchus'', '' Salmo'' and '' Salvelinus'', all of the subfamily Salmoninae of the family Salmonidae. The word ''trout'' is also used as part of the name of some non-salm ...
, needlefish, and
eel Eels are ray-finned fish belonging to the order Anguilliformes (), which consists of eight suborders, 19 families, 111 genera, and about 800 species. Eels undergo considerable development from the early larval stage to the eventual adult stage ...
s.
Chain pickerel The chain pickerel (''Esox niger'') is a species of freshwater fish in the pike family (family Esocidae) of order Esociformes. The chain pickerel and the American pickerel (''E. americanus'') belong to the ''Esox'' genus of pike. Taxonomy Fren ...
s (''Esox niger'') and
white sucker The white sucker (''Catostomus commersonii)'' is a species of freshwater cypriniform fish inhabiting the upper Midwest and Northeast in North America, but it is also found as far south as Georgia and as far west as New Mexico. The fish is common ...
s (''Catostomus commersonii'') are frequently taken in interior
Maine Maine () is a state in the New England and Northeastern regions of the United States. It borders New Hampshire to the west, the Gulf of Maine to the southeast, and the Canadian provinces of New Brunswick and Quebec to the northeast and ...
. Wintering eagles on the
Platte River The Platte River () is a major river in the State of Nebraska. It is about long; measured to its farthest source via its tributary, the North Platte River, it flows for over . The Platte River is a tributary of the Missouri River, which itsel ...
in
Nebraska Nebraska () is a state in the Midwestern region of the United States. It is bordered by South Dakota to the north; Iowa to the east and Missouri to the southeast, both across the Missouri River; Kansas to the south; Colorado to the sout ...
preyed mainly on American gizzard shads and common carp. Bald eagles are also known to eat the following fish species: rainbow trout (''Oncorhynchus mykiss''), white catfish (''Ameiurus catus''), rock greenling (''Hexagrammos lagocephalus''),
Pacific cod The Pacific cod (''Gadus macrocephalus)'' is a species of ray-finned fish in the family Gadidae. It is a bottom-dwelling fish found in the northern Pacific Ocean, mainly on the continental shelf and upper slopes, to depths of about . It can gro ...
(''Gadus macrocephalus''), Atka mackerel (''Pleurogrammus monopterygius''),
largemouth bass The largemouth bass (''Micropterus salmoides'') is a carnivorous freshwater gamefish in the Centrarchidae ( sunfish) family, a species of black bass native to the eastern and central United States, southeastern Canada and northern Mexico, bu ...
(''Micropterus salmoides''),
northern pike The northern pike (''Esox lucius'') is a species of carnivorous fish of the genus ''Esox'' (the pikes). They are typical of brackish and fresh waters of the Northern Hemisphere (''i.e.'' holarctic in distribution). They are known simply as a p ...
(''Esox lucius''), striped bass (''Morone saxatilis''), dogfish shark (''Squalidae.sp'') and
Blue walleye The blue walleye (''Sander vitreus'' var. ''glaucus''), also called the blue pike, was a unique color morph (formerly considered a subspecies) of walleye which was endemic to the Great Lakes of North America. Morphometric studies led biologists t ...
(''Sander vitreus''). 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 Lake Britton is a reservoir located in Shasta County, California. It is known for its wide variety of bass and trout. Its main body is situated to the west of State Route 89, and is mostly surrounded by PG&E Land, Forest Service Land, and McArthu ...
in California, fish measuring were taken 71.8% of the time by parent eagles while fish measuring were chosen only 25% of the time. At nests around
Lake Superior Lake Superior in central North America is the largest freshwater lake in the world by surface areaThe Caspian Sea is the largest lake, but is saline, not freshwater. and the third-largest by volume, holding 10% of the world's surface fresh wa ...
, the remains of fish (mostly suckers) were found to average in total length. In the Columbia River estuary, most preyed on by eagles were estimated to measure less than , but larger fish between or even exceeding in length also taken especially during the non-breeding seasons. In Neagle Lake, eagles frequently take
Northern pike The northern pike (''Esox lucius'') is a species of carnivorous fish of the genus ''Esox'' (the pikes). They are typical of brackish and fresh waters of the Northern Hemisphere (''i.e.'' holarctic in distribution). They are known simply as a p ...
, up to long. They can take fish up to at least twice their own weight, such as large
salmon Salmon () is the common name for several commercially important species of euryhaline ray-finned fish from the family Salmonidae, which are native to tributaries of the North Atlantic (genus ''Salmo'') and North Pacific (genus '' Oncorhy ...
s, carps, or
muskellunge The muskellunge ''(Esox masquinongy)'', often shortened to muskie, musky or lunge is a species of large freshwater predatory fish native to North America. It is the largest member of the pike family, Esocidae. Origin of name The name "muskell ...
(''Esox masquinongy''), though they are unable to fly away with it. Much larger marine fish such as
Pacific halibut The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...
(''Hippoglossus stenolepis'') and
lemon shark The lemon shark (''Negaprion brevirostris'') is a species of shark from the family Carcharhinidae and is classified as a Vulnerable species by the International Union for the Conservation of Nature. Lemon sharks can grow to in length. They are ...
s (''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. Bald eagles also regularly exploit water turbines which produce battered, stunned or dead fish easily consumed. Predators who leave behind scraps of dead fish that they kill, such as
brown bear The brown bear (''Ursus arctos'') is a large bear species found across Eurasia and North America. In North America, the populations of brown bears are called grizzly bears, while the subspecies that inhabits the Kodiak Islands of Alaska is ...
s (''Ursus arctos''),
gray wolves The wolf (''Canis lupus''; : wolves), also known as the gray wolf or grey wolf, is a large canine native to Eurasia and North America. More than thirty subspecies of ''Canis lupus'' have been recognized, and gray wolves, as popularly un ...
(''Canis lupus'') and red foxes (''Vulpes vulpes''), may be habitually followed in order to scavenge the kills secondarily. Once North Pacific salmon die off after spawning, usually local bald eagles eat salmon carcasses almost exclusively. Eagles in
Washington Washington commonly refers to: * Washington (state), United States * Washington, D.C., the capital of the United States ** A metonym for the federal government of the United States ** Washington metropolitan area, the metropolitan area centered o ...
need to consume of fish each day for survival, with adults generally consuming more than juveniles and thus reducing potential energy deficiency and increasing survival during winter.


Birds

Behind fish, the next most significant prey base for bald eagles are other
waterbirds A water bird, alternatively waterbird or aquatic bird, is a bird that lives on or around water. In some definitions, the term ''water bird'' is especially applied to birds in freshwater ecosystems, although others make no distinction from seabi ...
. The contribution of such birds to the eagle's diet is variable, depending on the quantity and availability of fish near the water's surface. Waterbirds can seasonally comprise from 7% to 80% of the prey selection for eagles in certain localities. Overall, birds are the most diverse group in the bald eagle's prey spectrum, with 200 prey species recorded. Bird species most preferred as prey by eagles tend to be medium-sized, such as
western grebe The western grebe (''Aechmophorus occidentalis'') is a species in the grebe family of water birds. Folk names include "dabchick", "swan grebe" and "swan-necked grebe". Western grebe fossils from the Late Pleistocene of southwest North America ...
s (''Aechmophorus occidentalis''), mallards (''Anas platyrhynchos''), and
American coot The American coot (''Fulica americana''), also known as a mud hen or pouldeau, is a bird of the family Rallidae. Though commonly mistaken for ducks, American coots are only distantly related to ducks, belonging to a separate order. Unlike the w ...
s (''Fulica americana'') as such prey is relatively easy for the much larger eagles to catch and fly with. American herring gull (''Larus smithsonianus'') are the favored avian prey species for eagles living around
Lake Superior Lake Superior in central North America is the largest freshwater lake in the world by surface areaThe Caspian Sea is the largest lake, but is saline, not freshwater. and the third-largest by volume, holding 10% of the world's surface fresh wa ...
. Black ducks (''Anas rubripes''),
common eider The common eider (pronounced ) (''Somateria mollissima''), also called St. Cuthbert's duck or Cuddy's duck, is a large ( in body length) sea-duck that is distributed over the northern coasts of Europe, North America and eastern Siberia. It breed ...
s (''Somateria mollissima''), and
double-crested cormorant The double-crested cormorant (''Nannopterum auritum'') is a member of the cormorant family of water birds. It is found near rivers and lakes, and in coastal areas, and is widely distributed across North America, from the Aleutian Islands in Al ...
s (''Phalacrocorax auritus'') are also frequently taken in coastal
Maine Maine () is a state in the New England and Northeastern regions of the United States. It borders New Hampshire to the west, the Gulf of Maine to the southeast, and the Canadian provinces of New Brunswick and Quebec to the northeast and ...
and
velvet scoter The velvet scoter (''Melanitta fusca''), also called a velvet duck,Buczacki, Stefan (2005) ''Fauna Britannica'', Hamlyn, London. is a large sea duck, which breeds over the far north of Europe and the Palearctic west of the Yenisey basin. The gen ...
(''Melanitta fusca'') was dominant prey in
San Miguel Island San Miguel Island (Chumash: ''Tuqan'') is the westernmost of California's Channel Islands, located across the Santa Barbara Channel in the Pacific Ocean, within Santa Barbara County, California. San Miguel is the sixth-largest of the eight Ch ...
. Due to easy accessibility and lack of formidable nest defense 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. Along some portions of the North Pacific coastline, bald eagles which had historically preyed mainly
kelp Kelps are large brown algae seaweeds that make up the order Laminariales. There are about 30 different genera. Despite its appearance, kelp is not a plant - it is a heterokont, a completely unrelated group of organisms. Kelp grows in "underwa ...
-dwelling fish and supplementally sea otter (''Enhydra lutris'') pups are now preying mainly on seabird colonies since both the fish (possibly due to overfishing) and otters (cause unknown) have had precipitous population declines, causing concern for seabird conservation. Because of this more extensive predation, some biologist has expressed concern that
murre ''Uria'' is a genus of seabirds in the auk family known in Britain as guillemots, in most of North America as murres, and in Newfoundland and Labrador as turr. These are medium-sized birds with mainly brown or black plumage in the breeding sea ...
s are heading for a "conservation collision" due to heavy eagle predation. Eagles have been confirmed to attack nocturnally active, burrow-nesting seabird species such as
storm petrel Storm-petrel may refer to one of two bird families, both in the order Procellariiformes, once treated as the same family. The two families are: * Northern storm petrels (''Hydrobatidae'') are found in the Northern Hemisphere, although some speci ...
s and
shearwater Shearwaters are medium-sized long-winged seabirds in the petrel family Procellariidae. They have a global marine distribution, but are most common in temperate and cold waters, and are pelagic outside the breeding season. Description These tub ...
s by digging out their burrows and feeding on all animals they find inside. If a bald eagle flies close by, waterbirds will often fly away en masse, though in other cases they may seemingly ignore a perched eagle. when the birds fly away from a colony, this exposed their unprotected eggs and nestlings to scavengers such as
gull Gulls, or colloquially seagulls, are seabirds of the family Laridae in the suborder Lari. They are most closely related to the terns and skimmers and only distantly related to auks, and even more distantly to waders. Until the 21st century ...
s. Larger waterbirds are occasionally prey as well, with wintering emperor geese (''Chen canagica'') and
snow geese The snow goose (''Anser caerulescens'') is a species of goose native to North America. Both white and dark morphs exist, the latter often known as blue goose. Its name derives from the typically white plumage. The species was previously placed ...
(''C. caerulescens''), which gather in large groups, sometimes becoming regular prey. Other large waterbirds hunted at least occasionally by bald eagles have included adults of
common murre The common murre or common guillemot (''Uria aalge'') is a large auk. It has a circumpolar distribution, occurring in low-Arctic and boreal waters in the North Atlantic and North Pacific. It spends most of its time at sea, only coming to land to ...
s (''Uria aalge''),
common loon The common loon or great northern diver (''Gavia immer'') is a large member of the loon, or diver, family of birds. Breeding adults have a plumage that includes a broad black head and neck with a greenish, purplish, or bluish sheen, blackish ...
s (''Gavis immer''),
great black-backed gull The great black-backed gull (''Larus marinus'') is the largest member of the gull family. Described by the Cornell Lab of Ornithology as "the king of the Atlantic waterfront", it is a very aggressive hunter, pirate, and scavenger. It breeds on t ...
s (''Larus marinus''),
sandhill crane The sandhill crane (''Antigone canadensis'') is a species of large crane of North America and extreme northeastern Siberia. The common name of this bird refers to habitat like that at the Platte River, on the edge of Nebraska's Sandhills on ...
s (''Grus canadensis''), great blue herons (''Ardea herodias''), Ross's geese (''Anser rossii''), Some waterbird prey can exceed the eagle's own weight.
Canada geese The Canada goose (''Branta canadensis''), or Canadian goose, is a large wild goose with a black head and neck, white cheeks, white under its chin, and a brown body. It is native to the arctic and temperate regions of North America, and it is o ...
(''Branta canadensis'') are occasionally taken, and predation on the largest subspecies (''Branta canadensis maxima'') has been reported. Adult birds larger than eagle themselves such as
tundra swan The tundra swan (''Cygnus columbianus'') is a small swan of the Holarctic. The two taxa within it are usually regarded as conspecific, but are also sometimes split into two species: Bewick's swan (''Cygnus bewickii'') of the Palaearctic and th ...
s (''Cygnus columbianus'') and
brown pelican The brown pelican (''Pelecanus occidentalis'') is a bird of the pelican family, Pelecanidae, one of three species found in the Americas and one of two that feed by diving into water. It is found on the Atlantic Coast from New Jersey to the mout ...
s (''Pelecanus occidentalis'') are known to killed. Additionally, chicks or fledgling of American white pelicans (''Pelecanus erythrorhynchos''),
trumpeter swan The trumpeter swan (''Cygnus buccinator'') is a species of swan found in North America. The heaviest living bird native to North America, it is also the largest extant species of waterfowl, with a wingspan of 185 to 250 cm (6 ft 2 in to 8 ft 2 ...
s (''Cygnus buccinator'') and
whooping crane The whooping crane (''Grus americana'') is the tallest North American bird, named for its whooping sound. It is an endangered crane species. Along with the sandhill crane (''Antigone canadensis''), it is one of only two crane species native to ...
s (''Grus americana'') can be taken by bald eagles, and unsuccessful attacks on adults have been reported. Bald eagles have been recorded as killing other raptors on occasion. In some cases, these may be attacks of competition or
kleptoparasitism Kleptoparasitism (etymologically, parasitism by theft) is a form of feeding in which one animal deliberately takes food from another. The strategy is evolutionarily stable when stealing is less costly than direct feeding, which can mean when f ...
on rival species but ended with the consumption of the victim. Nine species each of other
accipitrid The Accipitridae is one of the three families within the order Accipitriformes, and is a family of small to large birds with strongly hooked bills and variable morphology based on diet. They feed on a range of prey items from insects to medium-s ...
s and owls are known to have been preyed upon by bald eagles. Owl prey species have ranged in size from
western screech-owl The western screech owl (''Megascops kennicottii'') is a small owl native to North and Central America, closely related to the eastern screech owl. The scientific name commemorates the American naturalist Robert Kennicott. Description Length ...
s (''Megascops kennicotti'') to
snowy owl The snowy owl (''Bubo scandiacus''), also known as the polar owl, the white owl and the Arctic owl, is a large, white owl of the true owl family. Snowy owls are native to the Arctic regions of both North America and the Palearctic, breeding m ...
s (''Bubo scandiacus''). Larger diurnal raptors known to have fallen victim to bald eagles have included
red-tailed hawk The red-tailed hawk (''Buteo jamaicensis'') is a bird of prey that breeds throughout most of North America, from the interior of Alaska and northern Canada to as far south as Panama and the West Indies. It is one of the most common members wit ...
s (''Buteo jamaicensis''), peregrine falcons (''Falco peregrinus''), northern goshawks (''Accipiter gentilis''),
osprey The osprey (''Pandion haliaetus''), , also called sea hawk, river hawk, and fish hawk, is a diurnal, fish-eating bird of prey with a cosmopolitan range. It is a large raptor reaching more than in length and across the wings. It is brown o ...
s (''Pandion haliaetus'') and
black Black is a color which results from the absence or complete absorption of visible light. It is an achromatic color, without hue, like white and grey. It is often used symbolically or figuratively to represent darkness. Black and white ...
(''Coragyps atratus'') and
turkey vulture The turkey vulture (''Cathartes aura'') is the most widespread of the New World vultures. One of three species in the genus '' Cathartes'' of the family Cathartidae, the turkey vulture ranges from southern Canada to the southernmost tip of Sout ...
s (''Cathartes aura'').


Mammals

Mammalian preys are generally less frequently taken than fish or avian prey. However, in some regions, such as landlocked areas of North America, wintering bald eagles may become habitual predators of medium-sized mammals that occur in colonies or local concentrations, such as prairie dogs (''Cynomys'' sp.) and
jackrabbit Hares and jackrabbits are mammals belonging to the genus ''Lepus''. They are herbivores, and live solitarily or in pairs. They nest in slight depressions called forms, and their young are able to fend for themselves shortly after birth. The gen ...
s (''Lepus'' sp.). Bald eagles in
Seedskadee National Wildlife Refuge Seedskadee National Wildlife Refuge is a National Wildlife Refuge of the United States located in western Sweetwater County in the state of Wyoming. It covers 26,400 acres (106 km2) managed by the U.S. Fish and Wildlife Service, an age ...
often hunt in pair to catch rabbits and prairie dogs. They can attack and prey on rabbits and hares of nearly any size, from marsh rabbits (''Sylvilagus palustris'') to
black Black is a color which results from the absence or complete absorption of visible light. It is an achromatic color, without hue, like white and grey. It is often used symbolically or figuratively to represent darkness. Black and white ...
and white-tailed jackrabbits (''Lepus californicus'' & ''L. townsendii''), and
Arctic hare The Arctic hare (''Lepus arcticus'') is a species of hare highly adapted to living in the Arctic tundra and other icy biomes. The Arctic hare survives with shortened ears and limbs, a small nose, fat that makes up close to 20% of its body, and a ...
s (''Lepus arcticus''). In San Luis Valley, white-tailed jackrabbits can be important prey. Additionally, rodents such as
montane vole The montane vole (''Microtus montanus'') is a species of vole native to the western United States and Canada. Description Montane voles are medium-sized voles, with a total length of , including the tail. Adults typically weigh anything from , ...
s (''Microtus montanus''),
brown rat The brown rat (''Rattus norvegicus''), also known as the common rat, street rat, sewer rat, wharf rat, Hanover rat, Norway rat, Norwegian rat and Parisian rat, is a widespread species of common rat. One of the largest muroids, it is a brown o ...
s (''Rattus norvegicus''), muskrats (''Ondatra zibethicus''),
nutria The nutria (''Myocastor coypus''), also known as the coypu, is a large, herbivorous, semiaquatic rodent. Classified for a long time as the only member of the family Myocastoridae, ''Myocastor'' is now included within Echimyidae, the family of ...
s (''Myocastor coypus''), and various squirrels are taken as supplementary prey. Even American porcupines (''Erethizon dorsatum'') are reportedly attacked and killed. Where available, seal colonies can provide a lot of food. On Protection Island,
Washington Washington commonly refers to: * Washington (state), United States * Washington, D.C., the capital of the United States ** A metonym for the federal government of the United States ** Washington metropolitan area, the metropolitan area centered o ...
, they commonly feed on
harbor seal The harbor (or harbour) seal (''Phoca vitulina''), also known as the common seal, is a true seal found along temperate and Arctic marine coastlines of the Northern Hemisphere. The most widely distributed species of pinniped (walruses, eared se ...
(''Phoca vitulina'') afterbirths, still-borns and sickly seal pups. Similarly, bald eagles in Alaska readily prey on sea otter (''Enhydra lutris'') pups. Small mammalian carnivores can be taken infrequently, such as American martens (''Martes pennanti''),
American mink The American mink (''Neogale vison'') is a semiaquatic species of mustelid native to North America, though human intervention has expanded its range to many parts of Europe, Asia and South America. Because of range expansion, the American mink i ...
s (''Neogale vison''), and Island foxes ('' Urocyon littoralis ''). Larger carnivoran prey include grey foxes (''Urocyon cinereoargenteus''),
Arctic fox The Arctic fox (''Vulpes lagopus''), also known as the white fox, polar fox, or snow fox, is a small fox native to the Arctic regions of the Northern Hemisphere and common throughout the Arctic tundra biome. It is well adapted to living in ...
es (''Vulpes lagopus''), striped skunks (''Mephitis mephitis''), domestic cats (''Felis catus'') and reportedly red foxes (''Vulpes vulpus''). Predation on more formidable species such as adult
North American river otter The North American river otter (''Lontra canadensis''), also known as the northern river otter and river otter, is a semiaquatic mammal that only lives on the North American continent, along its waterways and coasts. An adult North American rive ...
s (''Lontra canadensis'') and male fisher cats (''Pekania pennanti''), and possibly common raccoons (''Procyon lotor'') have been reported. Even bobcat (''Lynx rufus'') has been recorded amongst their prey, but it is not known whether they were killed or scavenged. Other wild mammalian prey include fawns of deer such as
white-tailed deer The white-tailed deer (''Odocoileus virginianus''), also known as the whitetail or Virginia deer, is a medium-sized deer native to North America, Central America, and South America as far south as Peru and Bolivia. It has also been introduced t ...
(''Odocoileus virginianus'') and Sitka deer (''Odocoileus hemionus sitkensis''), which weigh around can be taken alive by bald eagles. In one instance, a bald eagle was observed carrying
mule deer The mule deer (''Odocoileus hemionus'') is a deer indigenous to western North America; it is named for its ears, which are large like those of the mule. Two subspecies of mule deer are grouped into the black-tailed deer. Unlike the related whi ...
(''Odocoileus hemionus'') fawn. Additionally,
Virginia opossum The Virginia opossum (''Didelphis virginiana''), also known as the North American opossum, is the only opossum living north of Mexico, its range extending south into Central America. It is the northernmost marsupial in the world. In the United S ...
s (''Didelphis virginiana'') can be preyed upon but most of them are mainly taken as roadkills due to their nocturnal habits. Together with the golden eagle, bald eagles are occasionally accused of preying on livestock, especially sheep (''Ovis aries''). There are a handful of proven cases of lamb predation, some specimens weighing up to , by bald eagles. Still, they are much less likely to attack a healthy lamb than a golden eagle. Both species prefer native, wild prey and are unlikely to cause any extensive detriment to human livelihoods. There is one case of a bald eagle killing and feeding on an adult, pregnant ewe (then joined in eating the kill by at least 3 other eagles), which, weighing on average over , is much larger than any other known prey taken by this species.


Reptiles and other prey

Supplemental prey is readily taken given the opportunity. In some areas, reptiles may become regular prey, especially in warm areas such as Florida where reptile diversity is high. Turtles are perhaps the most regularly hunted type of reptile. In coastal
New Jersey New Jersey is a state in the Mid-Atlantic and Northeastern regions of the United States. It is bordered on the north and east by the state of New York; on the east, southeast, and south by the Atlantic Ocean; on the west by the Delaware ...
, 14 of 20 studied eagle nests included remains of turtles. The main species found were common musk turtles (''Sternotherus odoratus''),
diamondback terrapin The diamondback terrapin or simply terrapin (''Malaclemys terrapin'') is a species of turtle native to the brackish coastal tidal marshes of the Northeastern and southern United States, and in Bermuda. It belongs to the monotypic genus ''Mal ...
(''Malaclemys terrapin'') and juvenile common snapping turtles (''Chelydra serpentina''). In these New Jersey nests, mainly subadult and small adults were taken, ranging in carapace length from . Similarly, many turtles were recorded in the diet in the
Chesapeake Bay The Chesapeake Bay ( ) is the largest estuary in the United States. The Bay is located in the Mid-Atlantic region and is primarily separated from the Atlantic Ocean by the Delmarva Peninsula (including the parts: the Eastern Shore of Maryland / ...
. In
Texas Texas (, ; Spanish: ''Texas'', ''Tejas'') is a state in the South Central region of the United States. At 268,596 square miles (695,662 km2), and with more than 29.1 million residents in 2020, it is the second-largest U.S. state by ...
,
softshell turtle The Trionychidae are a taxonomic family of a number of turtle genera, commonly known as softshell turtles. The family was erected by Leopold Fitzinger in 1826. Softshells include some of the world's largest freshwater turtles, though many can a ...
s are the most frequently taken prey, and a large number of Barbour's map turtles are taken in
Torreya State Park Torreya State Park is a 13,735 acre (56 km²) Florida State Park, United States National Natural Landmark and historic site thirteen miles (19 km) north of Bristol. It is located north of S.R 12 on the Apalachicola River, in northwes ...
. Other reptilian and amphibian prey includes
southern alligator lizard The southern alligator lizard (''Elgaria multicarinata'') is a common species of lizard in the Family (biology), family Anguidae. The species is native to the Pacific coast of North America. It ranges from Baja California to the state of Washingt ...
s (''Elgaria multicarinata''), snakes such as
garter snake Garter snake is a common name for generally harmless, small to medium-sized snakes belonging to the genus ''Thamnophis'' in the family Colubridae. Native to North and Central America, species in the genus ''Thamnophis'' can be found from the ...
s and rattlesnakes, and Greater siren (''Siren lacertina''). Invertebrates are occasionally taken. In
Alaska Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S. ...
, eagles feed on sea urchins (''Strongylocentrotus sp.''), chitons, mussels, and crabs. Other various mollusks such as land snails, abalones, bivalves, periwinkles, blue mussels, squids, and starfishes are taken as well.


Interspecific predatory relationships

When competing for food, eagles will usually dominate other fish-eaters and scavengers, aggressively displacing mammals such as coyotes (''Canis latrans'') and foxes, and birds such as
corvid Corvidae is a cosmopolitan family of oscine passerine birds that contains the crows, ravens, rooks, jackdaws, jays, magpies, treepies, choughs, and nutcrackers. In colloquial English, they are known as the crow family or corvids. Currently, ...
s,
gull Gulls, or colloquially seagulls, are seabirds of the family Laridae in the suborder Lari. They are most closely related to the terns and skimmers and only distantly related to auks, and even more distantly to waders. Until the 21st century ...
s, vultures and other raptors. Occasionally, coyotes, bobcats (''Lynx rufus'') and domestic dogs (''Canis familiaris'') can displace eagles from carrion, usually less confident immature birds, as has been recorded in Maine. Bald eagles are less active, bold predators than golden eagles and get relatively more of their food as carrion and from kleptoparasitism (although it is now generally thought that golden eagles eat more carrion than was previously assumed). However, the two species are roughly equal in size, aggressiveness and physical strength and so competitions can go either way. Neither species is known to be dominant, and the outcome depends on the size and disposition of the individual eagles involved. Wintering bald and golden eagles in
Utah Utah ( , ) is a state in the Mountain West subregion of the Western United States. Utah is a landlocked U.S. state bordered to its east by Colorado, to its northeast by Wyoming, to its north by Idaho, to its south by Arizona, and to it ...
both sometimes won conflicts, though in one recorded instance a single bald eagle successfully displaced two consecutive golden eagles from a kill. 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 golden eagles there are 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 New Jersey is a state in the Mid-Atlantic and Northeastern regions of the United States. It is bordered on the north and east by the state of New York; on the east, southeast, and south by the Atlantic Ocean; on the west by the Delaware ...
during winter, a golden eagle and numerous bald eagles were observed to hunt
snow geese The snow goose (''Anser caerulescens'') is a species of goose native to North America. Both white and dark morphs exist, the latter often known as blue goose. Its name derives from the typically white plumage. The species was previously placed ...
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 The white-tailed deer (''Odocoileus virginianus''), also known as the whitetail or Virginia deer, is a medium-sized deer native to North America, Central America, and South America as far south as Peru and Bolivia. It has also been introduced t ...
(''Odocoileus virginianus'') in remote forest clearings in the eastern
Appalachian Mountains The Appalachian Mountains, often called the Appalachians, (french: Appalaches), are a system of mountains in eastern to northeastern North America. The Appalachians first formed roughly 480 million years ago during the Ordovician Period. They ...
without apparent conflict. Bald eagles as 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
osprey The osprey (''Pandion haliaetus''), , also called sea hawk, river hawk, and fish hawk, is a diurnal, fish-eating bird of prey with a cosmopolitan range. It is a large raptor reaching more than in length and across the wings. It is brown o ...
s, herons and even otters. They have also been recorded opportunistically pirating birds from peregrine falcons (''Falco peregrinus''), prairie dogs from
ferruginous hawk The ferruginous hawk, (''Buteo regalis''), is a large bird of prey and belongs to the broad-winged buteo hawks. An old colloquial name is ferrugineous rough-leg, due to its similarity to the closely related rough-legged hawk (''B. lagopus''). ...
s (''Buteo regalis'') and even jackrabbits from
golden eagle The golden eagle (''Aquila chrysaetos'') is a bird of prey living in the Northern Hemisphere. It is the most widely distributed species of eagle. Like all eagles, it belongs to the family Accipitridae. They are one of the best-known birds of ...
s. 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 predator An apex predator, also known as a top predator, is a predator at the top of a food chain, without natural predators of its own. Apex predators are usually defined in terms of trophic dynamics, meaning that they occupy the highest trophic lev ...
s.


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. It is thought that bald eagles
mate for life In biology, a pair bond is the strong affinity that develops in some species between a mating pair, often leading to the production and rearing of offspring and potentially a lifelong bond. Pair-bonding is a term coined in the 1940s that is freque ...
. However, if one member of a pair dies or disappears, the survivor will choose a new mate. A pair which 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. The 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. Compared to most other raptors, which mostly nest in April or May, bald eagles are early breeders: nest building or reinforcing is often by mid-February, egg laying is often late February (sometimes during deep snow in the North), and incubation is usually mid-March and early May. Eggs hatch from mid April to early May, and the young fledge late June to early July. The nest is the largest of any bird in North America; it is used repeatedly over many years and with new material added each year may eventually be as large as deep, across and weigh . One nest in Florida was found to be deep, across, and to weigh . 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. The nest is built of branches, usually in large trees found near water. When breeding where there are no trees, the bald eagle will nest on the ground, as has been recorded largely in areas largely isolated from terrestrial predators, such as
Amchitka Island Amchitka (; ale, Amchixtax̂; russian: Амчитка) is a volcanic, tectonically unstable and uninhabited island in the Rat Islands group of the Aleutian Islands in southwest Alaska. It is part of the Alaska Maritime National Wildlife Re ...
in Alaska. In Sonora, Mexico, eagles have been observed nesting on top of hecho catcuses (''Pachycereus pectin-aboriginum''). Nests located on cliffs and rock pinnacles have been reported historically in California,
Kansas Kansas () is a state in the Midwestern United States. Its capital is Topeka, and its largest city is Wichita. Kansas is a landlocked state bordered by Nebraska to the north; Missouri to the east; Oklahoma to the south; and Colorado to th ...
,
Nevada Nevada ( ; ) is a state in the Western region of the United States. It is bordered by Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. Nevada is the 7th-most extensive, ...
,
New Mexico ) , population_demonym = New Mexican ( es, Neomexicano, Neomejicano, Nuevo Mexicano) , seat = Santa Fe , LargestCity = Albuquerque , LargestMetro = Tiguex , OfficialLang = None , Languages = English, Spanish ( New Mexican), Navajo, Ke ...
and
Utah Utah ( , ) is a state in the Mountain West subregion of the Western United States. Utah is a landlocked U.S. state bordered to its east by Colorado, to its northeast by Wyoming, to its north by Idaho, to its south by Arizona, and to it ...
, but currently are only verified to occur only in
Alaska Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S. ...
and
Arizona Arizona ( ; nv, Hoozdo Hahoodzo ; ood, Alĭ ṣonak ) is a state in the Southwestern United States. It is the 6th largest and the 14th most populous of the 50 states. Its capital and largest city is Phoenix. Arizona is part of the Fou ...
. The eggs average about long, ranging from , and have a breadth of , ranging from . Eggs in Alaska averaged in mass, while in
Saskatchewan Saskatchewan ( ; ) is a province in western Canada, bordered on the west by Alberta, on the north by the Northwest Territories, on the east by Manitoba, to the northeast by Nunavut, and on the south by the U.S. states of Montana and North Dak ...
they averaged . As with their ultimate body size, egg size tends to increase with distance from the equator. Eagles produce between one and three eggs per year, two being typical. Rarely, four eggs have been found in nests, but these may be exceptional cases of
polygyny Polygyny (; from Neoclassical Greek πολυγυνία (); ) is the most common and accepted form of polygamy around the world, entailing the marriage of a man with several women. Incidence Polygyny is more widespread in Africa than in any ...
. Eagles in captivity have been capable of producing up to seven eggs. It is rare for all three chicks to successfully reach the fledgling stage. The oldest chick often bears the advantage of larger size and louder voice, which tends to draw the parents' attention towards it. Occasionally, as is recorded in many large raptorial birds, the oldest sibling sometimes attacks and kills its younger sibling(s), especially early in the nesting period when their sizes are most different. However, nearly half of known bald eagles produce two fledglings (more rarely three), unlike in some other "eagle" species such as some in the genus ''Aquila'', in which a second fledgling is typically observed in less than 20% of nests, despite two eggs typically being laid. Both the male and female take turns incubating the eggs, but the female does most of the sitting. The parent not incubating will hunt for food or look for nesting material during this stage. For the first two to three weeks of the nestling period, at least one adult is at the nest almost 100% of the time. After five to six weeks, the attendance of parents usually drops off considerably (with the parents often perching in trees nearby). A young eaglet can gain up to a day, the fastest growth rate of any North American bird. The young eaglets pick up and manipulate sticks, play tug of war with each other, practice holding things in their talons, and stretch and flap their wings. By eight weeks, the eaglets are strong enough to flap their wings, lift their feet off the nest platform, and rise up in the air. The young fledge at anywhere from 8 to 14 weeks of age, though will remain close to the nest and attended to by their parents for a further 6 weeks. Juvenile eagles first start dispersing away from their parents about 8 weeks after they fledge. Variability in departure date related to effects of sex and hatching order on growth and development. For the next four years, immature eagles wander widely in search of food until they attain adult plumage and are eligible to reproduce. 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 The red-tailed hawk (''Buteo jamaicensis'') is a bird of prey that breeds throughout most of North America, from the interior of Alaska and northern Canada to as far south as Panama and the West Indies. It is one of the most common members wit ...
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. In
Prince William Sound Prince William Sound ( Sugpiaq: ''Suungaaciq'') is a sound of the Gulf of Alaska on the south coast of the U.S. state of Alaska. It is located on the east side of the Kenai Peninsula. Its largest port is Valdez, at the southern terminus of the T ...
in
Alaska Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S. ...
, adults had an annual survival rate of 88% even after the Exxon Valdez oil spill adversely affected eagles in the area. Of 1,428 individuals from across the range necropsied by National Wildlife Health Center from 1963 to 1984, 329 (23%) eagles died from trauma, primarily impact with wires and vehicles; 309 (22%) died from gunshot; 158 (11%) died from poisoning; 130 (9%) died from electrocution; 68 (5%) died from trapping; 110 (8%) from emaciation; and 31 (2%) from disease; cause of death was undetermined in 293 (20%) of cases. In this study, 68% of mortality was human-caused. Today, eagle-shooting is believed to be considerably reduced due to the species' protected status. In one case, an adult eagle investigating a peregrine falcon nest for prey items sustained a concussion from a swooping parent peregrine, and ultimately died days later from it. An early natural history video depicting a cougar (''Puma concolor'') ambushing and killing an immature bald eagle feeding at a rabbit carcass is viewable online, although this film may have been staged. Most non-human-related mortality involves nestlings or eggs. Around 50% of eagles survive their first year. However, in the Chesapeake Bay area, 100% of 39 radio-tagged nestlings survived to their first year. Nestling or egg fatalities may be due to nest collapses, starvation, sibling aggression or inclement weather. Another significant cause of egg and nestling mortality is predation. Nest predators include large
gull Gulls, or colloquially seagulls, are seabirds of the family Laridae in the suborder Lari. They are most closely related to the terns and skimmers and only distantly related to auks, and even more distantly to waders. Until the 21st century ...
s,
corvid Corvidae is a cosmopolitan family of oscine passerine birds that contains the crows, ravens, rooks, jackdaws, jays, magpies, treepies, choughs, and nutcrackers. In colloquial English, they are known as the crow family or corvids. Currently, ...
s (including ravens,
crows The Common Remotely Operated Weapon Station (CROWS) is a series of remote weapon stations used by the US military on its armored vehicles and ships. It allows weapon operators to engage targets without leaving the protection of their vehicle. ...
and magpies),
wolverine The wolverine (), (''Gulo gulo''; ''Gulo'' is Latin for " glutton"), also referred to as the glutton, carcajou, or quickhatch (from East Cree, ''kwiihkwahaacheew''), is the largest land-dwelling species of the family Mustelidae. It is a muscul ...
s (''Gulo gulo''),
fishers Fisher is an archaic term for a fisherman, revived as gender-neutral. Fisher, Fishers or The Fisher may also refer to: Places Australia *Division of Fisher, an electoral district in the Australian House of Representatives, in Queensland *Elect ...
(''Pekania pennanti''),
red-tailed hawk The red-tailed hawk (''Buteo jamaicensis'') is a bird of prey that breeds throughout most of North America, from the interior of Alaska and northern Canada to as far south as Panama and the West Indies. It is one of the most common members wit ...
s, owls, other
eagle Eagle is the common name for many large birds of prey of the family Accipitridae. Eagles belong to several groups of genera, some of which are closely related. Most of the 68 species of eagle are from Eurasia and Africa. Outside this area, j ...
s, bobcats, American black bears (''Ursus americanus'') and raccoons. 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. Nestlings are usually exempt from predation by terrestrial carnivores that are poor tree-climbers, but
Arctic fox The Arctic fox (''Vulpes lagopus''), also known as the white fox, polar fox, or snow fox, is a small fox native to the Arctic regions of the Northern Hemisphere and common throughout the Arctic tundra biome. It is well adapted to living in ...
es (''Vulpes lagopus'') occasionally snatched nestlings from ground nests on Amchitka Island in Alaska before they were extirpated from the island. The bald eagle will defend its nest fiercely from all comers and has even repelled attacks from bears, having been recorded knocking a black bear out of a tree when the latter tried to climb a tree holding nestlings.


Relationship with humans


Population decline and recovery

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 Dichlorodiphenyltrichloroethane, commonly known as DDT, is a colorless, tasteless, and almost odorless crystalline chemical compound, an organochloride. Originally developed as an insecticide, it became infamous for its environmental impacts. ...
. Bald eagles, like many birds of prey, were especially affected by DDT due to
biomagnification Biomagnification, also known as bioamplification or biological magnification, is any concentration of a toxin, such as pesticides, in the tissues of tolerant organisms at successively higher levels in a food chain. This increase can occur as a ...
. DDT itself was not lethal to the adult bird, but it interfered with their
calcium Calcium is a chemical element with the symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar t ...
metabolism, making them either sterile or unable to lay healthy eggs; many of their eggs were too brittle to withstand the weight of a brooding adult, making it nearly impossible for them to hatch. It is estimated that in the early 18th century the bald eagle population was 300,000–500,000, but by the 1950s there were only 412 nesting pairs in the 48 contiguous states of the US. 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. The species was first protected in the U.S. and Canada by the 1918 Migratory Bird Treaty, later extended to all of North America. The
Bald and Golden Eagle Protection Act The Bald and Golden Eagle Protection Act (16 U.S.C. 668-668d) is a United States federal statute that protects two species of eagle. The bald eagle was chosen as a national emblem of the United States by the Continental Congress of 1782 and w ...
, approved by the U.S. Congress in 1940, protected the bald eagle and the
golden eagle The golden eagle (''Aquila chrysaetos'') is a bird of prey living in the Northern Hemisphere. It is the most widely distributed species of eagle. Like all eagles, it belongs to the family Accipitridae. They are one of the best-known birds of ...
, prohibiting commercial trapping and killing of the birds. 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. DDT was completely banned in Canada in 1989, though its use had been highly restricted since the late 1970s. With regulations in place and DDT banned, the eagle population rebounded. The bald eagle can be found in growing concentrations throughout the United States and Canada, particularly near large bodies of water. In the early 1980s, the estimated total population was 100,000 individuals, with 110,000–115,000 by 1992; the U.S. state with the largest resident population is
Alaska Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S. ...
, with about 40,000–50,000, with the next highest population the Canadian province of
British Columbia British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, ...
with 20,000–30,000 in 1992. Obtaining a precise count of the bald eagle population is extremely difficult. The most recent data submitted by individual states was in 2006, when 9789 breeding pairs were reported. 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. Today, the contiguous state with the largest number of breeding pairs of eagles is
Minnesota Minnesota () is a state in the upper midwestern region of the United States. It is the 12th largest U.S. state in area and the 22nd most populous, with over 5.75 million residents. Minnesota is home to western prairies, now given over to ...
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 now have at least 100 breeding pairs of bald eagles. In Washington State, there were only 105 occupied nests in 1980. That number increased by about 30 per year, so that by 2005 there were 840 occupied nests. 2005 was the last year that the Washington Department of Fish and Wildlife counted occupied nests. Further population increases in Washington may be limited by the availability of late winter food, particularly salmon. 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 A least-concern species is a species that has been categorized by the International Union for Conservation of Nature (IUCN) as evaluated as not being a focus of species conservation because the specific species is still plentiful in the wild. T ...
category on the
IUCN Red List The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biol ...
. In the ''Exxon Valdez'' oil spill of 1989 an estimated 247 were killed in
Prince William Sound Prince William Sound ( Sugpiaq: ''Suungaaciq'') is a sound of the Gulf of Alaska on the south coast of the U.S. state of Alaska. It is located on the east side of the Kenai Peninsula. Its largest port is Valdez, at the southern terminus of the T ...
, though the local population returned to its pre-spill level by 1995. In some areas, the increase in eagles has led to decreases in other bird populations and the eagles may be considered a pest.


Killing permits

In December 2016, the U.S. Fish and Wildlife Service proposed quadrupling the number of bald eagles that can be killed by the wind electric generation industry without paying a penalty to 4,200 per year. If issued, the permits would last 30 years, six times the current 5-year permits.


In captivity

Permits are required to keep bald eagles in captivity in the United States. Permits are primarily issued to public educational institutions, and the eagles which 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 and facilities, 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. In Canada and in England a license is required to keep bald eagles for falconry. Bald eagles cannot legally be kept for falconry in the United States, but a license may be issued in some jurisdictions to allow use of such eagles in birds-of-prey flight shows.


Cultural significance

The bald eagle is important in various Native American cultures and, as the
national bird This is a list of national birds, including official birds of overseas territories and other states described as nations. Most species in the list are officially designated. Some species hold only an "unofficial" status. National birds See al ...
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 The golden eagle (''Aquila chrysaetos'') is a bird of prey living in the Northern Hemisphere. It is the most widely distributed species of eagle. Like all eagles, it belongs to the family Accipitridae. They are one of the best-known birds of ...
, are central to many religious and spiritual customs among Native Americans. Eagles are considered spiritual messengers between gods and humans by some cultures. Many pow wow dancers use the eagle claw as part of their regalia as well. Eagle feathers are often used in traditional ceremonies, particularly in the construction of regalia worn and as a part of fans, bustles and head dresses. In the Navajo tradition an eagle feather is represented to be a protector, along with the feather Navajo medicine men use the leg and wing bones for ceremonial whistles. The
Lakota Lakota may refer to: * Lakota people, a confederation of seven related Native American tribes *Lakota language, the language of the Lakota peoples Place names In the United States: * Lakota, Iowa * Lakota, North Dakota, seat of Nelson County * La ...
, 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
Pawnee Pawnee initially refers to a Native American people and its language: * Pawnee people * Pawnee language Pawnee is also the name of several places in the United States: * Pawnee, Illinois * Pawnee, Kansas * Pawnee, Missouri * Pawnee City, Nebraska ...
considered eagles as symbols of fertility because their nests are built high off the ground and because they fiercely protect their young. The Choctaw considered the bald eagle, who has direct contact with the upper world of the sun, as a symbol of peace. During the
Sun Dance The Sun Dance is a ceremony practiced by some Native Americans in the United States and Indigenous peoples in Canada, primarily those of the Plains cultures. It usually involves the community gathering together to pray for healing. Individua ...
, which is practiced by many
Plains Indian Plains Indians or Indigenous peoples of the Great Plains and Canadian Prairies are the Native American tribes and First Nation band governments who have historically lived on the Interior Plains (the Great Plains and Canadian Prairies) of ...
tribes, the eagle is represented in several ways. The eagle nest is represented by the fork of the lodge where the dance is held. A whistle made from the wing bone of an eagle is used during the course of the dance. Also during the dance, a
medicine man A medicine man or medicine woman is a traditional healer and spiritual leader who serves a community of Indigenous people of the Americas. Individual cultures have their own names, in their respective languages, for spiritual healers and cerem ...
may direct his fan, which is made of eagle feathers, to people who seek to be healed. The medicine man touches the fan to the center pole and then to the patient, in order to transmit power from the pole to the patient. The fan is then held up toward the sky, so that the eagle may carry the prayers for the sick to the Creator. Current eagle feather law stipulates that only individuals of certifiable Native American ancestry enrolled in a federally recognized tribe are legally authorized to obtain or possess bald or golden eagle feathers for religious or spiritual use. The constitutionality of these laws has been questioned by Native American groups on the basis that it violates the
First Amendment First or 1st is the ordinal form of the number one (#1). First or 1st may also refer to: *World record, specifically the first instance of a particular achievement Arts and media Music * 1$T, American rapper, singer-songwriter, DJ, and reco ...
by affecting ability to practice their religion freely. The National Eagle Repository, a division of the FWS, exists as a means to receive, process, and store bald and
golden eagle The golden eagle (''Aquila chrysaetos'') is a bird of prey living in the Northern Hemisphere. It is the most widely distributed species of eagle. Like all eagles, it belongs to the family Accipitridae. They are one of the best-known birds of ...
s which are found dead and to distribute the eagles, their parts and feathers to
federally recognized This is a list of federally recognized tribes in the contiguous United States of America. There are also federally recognized Alaska Native tribes. , 574 Indian tribes were legally recognized by the Bureau of Indian Affairs (BIA) of the United ...
Native American tribes for use in religious ceremonies.


National bird of the United States

The bald eagle is the national bird of the United States of America. The founders of the United States were fond of comparing their new republic with the
Roman Republic The Roman Republic ( la, Res publica Romana ) was a form of government of Rome and the era of the classical Roman civilization when it was run through public representation of the Roman people. Beginning with the overthrow of the Roman Ki ...
, in which eagle imagery (usually involving the
golden eagle The golden eagle (''Aquila chrysaetos'') is a bird of prey living in the Northern Hemisphere. It is the most widely distributed species of eagle. Like all eagles, it belongs to the family Accipitridae. They are one of the best-known birds of ...
) 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 The olive branch is a symbol of peace and victory associated with customs of ancient Greece and connected with supplication to gods and persons in power. It is found in most cultures of the Mediterranean basin and became associated with peace ...
with thirteen leaves with its talons. The bald eagle appears on most official seals of the U.S. government, including the presidential seal, the presidential flag, and in the logos of many U.S. federal agencies. Between 1916 and 1945, the presidential flag (but not the seal) showed an eagle facing to its left (the viewer's right), which gave rise to the
urban legend An urban legend (sometimes contemporary legend, modern legend, urban myth, or urban tale) is a genre of folklore comprising stories or fallacious claims circulated as true, especially as having happened to a "friend of a friend" or a family m ...
that the flag is changed to have the eagle face towards the olive branch in peace, and towards the arrows in wartime. Contrary to popular legend, there is no evidence that
Benjamin Franklin Benjamin Franklin ( April 17, 1790) was an American polymath who was active as a writer, scientist, inventor, statesman, diplomat, printer, publisher, and political philosopher. Encyclopædia Britannica, Wood, 2021 Among the leading inte ...
ever publicly supported the
wild turkey The wild turkey (''Meleagris gallopavo'') is an upland ground bird native to North America, one of two extant species of turkey and the heaviest member of the order Galliformes. It is the ancestor to the domestic turkey, which was originally d ...
(''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 of its being a large predator, the bald eagle has many representations in popular culture. In film and television depictions the call of the
red-tailed hawk The red-tailed hawk (''Buteo jamaicensis'') is a bird of prey that breeds throughout most of North America, from the interior of Alaska and northern Canada to as far south as Panama and the West Indies. It is one of the most common members wit ...
, which is much louder and more powerful, is often substituted for bald eagles.Jessica Robinson,
Bald Eagle: A Mighty Symbol, With A Not-So-Mighty Voice
;
NPR National Public Radio (NPR, stylized in all lowercase) is an American privately and state funded nonprofit media organization headquartered in Washington, D.C., with its NPR West headquarters in Culver City, California. It differs from other ...
, July 2, 2012; accessed 2019.08.23.


See also

*
American bison The American bison (''Bison bison'') is a species of bison native to North America. Sometimes colloquially referred to as American buffalo or simply Bubalina, buffalo (a different clade of bovine), it is one of two extant species of bison, alongs ...
* Besnard Lake * Eagle lady *
Coat of arms of the Philippines The coat of arms of the Philippines ( fil, Sagisag ng Pilipinas; es, Escudo de Filipinas) features the eight-rayed sun of the Philippines with each ray representing the eight provinces (Batangas, Bulacan, Cavite, Manila, Laguna, Nueva Ecija ...
*
List of national birds This is a list of national birds, including official birds of overseas territories and other states described as nations. Most species in the list are officially designated. Some species hold only an "unofficial" status. National birds See a ...


References


Further reading

* * * * * * * *


Identification

* Grant, Peter J. (1988) "The Co. Kerry Bald Eagle" '' Twitching'' 1(12): 379–80 – describes plumage differences between bald eagle and white-tailed eagle in juveniles


External links


The National Eagle Center

American Bald Eagle Foundation

American Bald Eagle Information

Bald eagle bird sound
– Florida Museum of Natural History


Video links

* *
Photo field guide on Flickr


{{Featured article bald eagle bald eagle Scavengers Birds of Canada Birds of the United States Birds of Mexico Birds of Saint Pierre and Miquelon Birds of prey of North America Native birds of the Rocky Mountains National symbols of the United States bald eagle Taxa named by Carl Linnaeus Least concern biota of North America Least concern biota of the United States