Bald Eagle Haliaeetus leucocephalus Scientific name definitions

David A. Buehler
Version: 2.0 — Published October 7, 2022


Geographic Variation

Size (wing chord and tail length) and mass of individuals increases with latitude in a clinal pattern of gradation, with only populations breeding at northerly and southerly extremes clearly differentiated (18). See also Measurements.


Traditionally, two subspecies ('northern' and 'southern') have been recognized (e.g., 10, 41, 42, 43), diagnosed on the basis of body size (see Appendix 3). However, variation in clinal measurements is sufficient such that no clear demarcation can be drawn between “northern” and “southern” populations (1). Moreover, movement among populations, both south-to-north and north-to-south, may span thousands of kilometers (44, 45, 46, 47), even if the extent of gene exchange is unknown, which makes identification of any given non-breeding individual impossible. As a result, other authorities recognize only one subspecies, including Amadon (48), Palmer (1), and Gibson and Withrow (49).

Note that if two subspecies are recognized, neither H. l. washingtonii (50) nor H. l. washingtoniensis (51)—with a type locality of Henderson, Kentucky—should stand as valid because the given description of the type specimen is several standard deviations too large for even the largest Haliaeetus eagle, and thus cannot be referable to any particular extant population (52). Both names, nonetheless, have been used for northern breeders (53, 54). Apart from these unidentifiable taxa, there are several synonyms of Haliaeetus leucocephalus (Linneaus, 1766): Aquila pygargus Dumont, 1816; Haliaeetus leucocephalus alascanus C. H. Townsend, 1897; Haliaeetus leucocephalus washingtoni (53) (per 52); Haliaeetus leucocephalus floridana (55); and Haliaeetus leucocephalus washingtoniensis (54) (per 52).


Haliaeetus leucocephalus washingtoniensis Scientific name definitions

Systematics History

Falco Washingtonii Audubon, 1827, Birds of America (folio), pl. 11.—Henderson, Kentucky (fide Audubon, 1831, Ornithological Biography, Volume 1, p. 60).

Audubon referred to this bird by three different names in rapid succession: as Falco washingtoniensis (in the catalog to an 1826 exhibition of his work at the Edinburgh Royal Institution), then as Falco Washingtonii in the plate in Birds of America, and finally Fálco Washingtoniàna in Audubon (56). There is no known type specimen, indeed Audubon (56) claimed that it was already lost by the time his name was published, only the illustration of the bird that Audubon dubbed “The Bird of Washington”. As described by Halley (57), the name “is still known only from Audubon's anecdotes and plate, and secondary (anecdotal) sightings by his friends.” Halley went on to contend that “Audubon's painting of the Bird of Washington was not ‘faithfully figured from a fresh-killed specimen’, as he claimed, but was the product of both plagiarism and invention [...,] an elaborate lie that Audubon concocted to convince members of the English nobility who were sympathetic to American affairs, to subscribe to and promote his work.” Because of the ambiguities surrounding the name washingtonii (and its variants), the AOU (58) considered that Townsend’s name alascanus (see below) should be used for the northern subspecies by those who prefer to recognize subspecific variation in this eagle, however Stresemann and Amadon (59) reasserted the primacy of Audubon’s name.

Haliaetus leucocephalus alascanus C. H. Townsend, 1897, Proceedings of the Biological Society of Washington 11:145.—Unalaska, Aleutian Islands. The holotype is a male, collected by C. H. Townsend on 22 June 1895 (not May as stated in the original description), and held at the National Museum of Natural History, Smithsonian Institution, Washington, D.C. (USNM 151567) (60).


Aleutian Islands, Alaska and Canada east to Labrador and Nova Scotia, south in United States to Oregon, Utah, central Kansas, and Illinois; inland Alaskan and Canadian populations winter from coastal Alaska and Canada south to United States and Mexico.

Identification Summary

Subspecies washingtoniensis is larger than subspecies leucocephalus, but size variation is clinal; no discernable differences in plumage (61).


Haliaeetus leucocephalus leucocephalus Scientific name definitions

Systematics History

Falco leucocephalus Linnaeus, 1766, Systema Naturae, 12th edition, Volume 1, p. 124.—Carolina. (ex Catesby, The Natural History of Carolina, Florida and the Bahama Islands, Volume 1, p. 1, Plate 1.)

Linnaeus based his description on the description and illustration provided by Catesby, and no type specimen exists.

Haliaeetus floridana H. H. Bailey, 1930, Bulletin of the Bailey Museum and Library of Natural History 4:[2].—lower Florida Peninsula. No type material was specifically designated in the original description, and Hubbard and Banks (62) believed that no suitable specimen existed in Harold Bailey’s collection when it arrived at the National Museum of Natural History, Smithsonian Institution, Washington, D.C., thus they declined to nominate a lectotype.


Southern United States (California and Arizona east to Virginia and Florida) south to northwestern Mexico (Baja California and Sonora).

Identification Summary

Subspecies leucocephalus is smaller than subspecies washingtoniensis, but size variation is clinal; no discernable differences in plumage (61).

Related Species

Among the ten species of fish-eagles (Haliaeetus) (43), the Bald Eagle is sister to and forms a superspecies with the White-tailed Eagle (Haliaeetus albicilla) of Eurasia (63, 64, 65).


Ethno-Ornithology and Names

The Bald Eagle occupies a place in the lore and cultural lexicon of many cultures. An incomplete list of names that refer to the Bald Eagle by language is below:

  • Alutiiq: kuckalaq.
  • Apache: itsáɫigai (66).
  • Bankalachi Toloim: o'-wik (67).
  • Shoshone: be'-ah gwin'-nah (Big Smokey Valley)(67).
  • Cahuilla: pah-moos (67).
  • Clallam: kwai-eng-s'll (68).
  • Chemehuevi: pah'-wung; pah'-wik; no-no'-nov (67).
  • Chumash: mahCH-he'-wah (Ineseno), tʃinatʸi (Obispeno), mah'-ke-wo (Ventureno)(67).
  • Cherokee: awohili (69).
  • Cheyenne: vóaxaa'e.
  • Choctaw: onsi, ta la'ko.
  • Crow: dúuptakoischialeaxe (69).
  • Cupeño: ˈpaʔmuʃ (67).
  • Eyak: gujgAlaG.
  • Gabrielino: ˈpa:mʔoş (67).
  • Gwich'in: tadhaa, tth’ak.
  • Hidatsa: iphoki, maisu, tsátsi (70); íibadagi (69).
  • Hopi: nuvakwahu.
  • Iipay: 'Aa: expa uru (67).
  • Inupiaq: tiŋmiaqpak (71).
  • Kawaiisu: pa-wiku (67).
  • Kitanemuk: pamoiš (67).
  • Koyukon: tokk'aade.
  • Lakota: anúnkasan (72); pe'sla wanbli (69).
  • Lenape: woapalanne (69).
  • Luiseño: páam'ush (67).
  • Menomini: pinashi (69).
  • Miwok: pahn'-nak sool (Lake), ho'-pah (Plains)(67).
  • Maidu: bo-po-să (67).
  • Mohegan: wôpsukuhq (69).
  • Mojave: ɂaspa 'achii kwachtha (67).
  • Mono: kwin'-nah a-bah hu-ah-kwe (Western) (67).
  • Navajo: atsáhąą (69).
  • Nisenan: took-took' (67).
  • Ojibwe: migizi (69); bapashko-giniw.
  • Osage: qiiea' pa sa (69).
  • Paiute: bo-po-toha tsopege ggwe'na'a (Northern), si'-kwah (Southern)(67).
  • Quapaw: xa-da ska (69).
  • Salinan: mut'-trahl trah'-ko si'-yŭ (A) (67).
  • Samish: kw’élengsen.
  • Selish: P'kal-qke' (73).
  • Sm’algyax (Tsimshian): ckshgeeg, xsgyiik.
  • Tanana: tok'adi.
  • Tlingit (Lingít): ch’áak’ (75).
  • Ute: píą-gwaná-cI (67).
  • Wappo: ah-wā-ko'-mah (67).
  • Washo: gă'-wet-ah-mah'-hah (67).
  • Wintu: moi'-e-hahs, moi'-ye-hus (67).
  • Xaad Kíl (Haida): ts'áak'.
  • Yakama: k'ámamul (69).
  • Yokuts: o-wik' (Palewyami), owik (Yawdanchi, Yowlumne) (67).
  • Yuki: pahl' MWO (67).
  • Yuma: as-spah'-et-se'-kwit-sah' (67).
  • Yup'ik: metervik, metervak, tengmiarrluk, yaqulegpak, yaqulpak (76).
  • Zuni: bak'oha k'yak'yali (69).

Fossil History

Fossil evidence of the Bald Eagle dates back at least 1 million years, though it likely existed prior to that (18). Fossils have been reported from the Pleistocene epoch in Oregon, California (four sites), New Mexico, Nebraska, Michigan, and Florida (three sites), and have been reported at prehistoric sites in Alaska (eight sites), Washington, Oregon, California, Arizona, South Dakota (many sites), Iowa, Illinois (four sites), Georgia, and at two sites in Florida (77, 78, 1). The extensive collection from Rancho La Brea, California, documented little change in tarsometatarsus size over past 35,000 years (79).

Recommended Citation

Buehler, D. A. (2022). Bald Eagle (Haliaeetus leucocephalus), version 2.0. In Birds of the World (P. G. Rodewald and S. G. Mlodinow, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.baleag.02