The great horned owl (Bubo virginianus), also known as the tiger owl (originally derived from early naturalists' description as the "winged tiger" or "tiger of the air") or the hoot owl, is a large owl native to the Americas. It is an extremely adaptable bird with a vast range and is the most widely distributed true owl in the Americas. Its diet consists primarily of rabbits and hares, rats and mice, and voles; it remains one of the few regular predators of skunk. Hunting also includes rodents, larger mid-sized mammals, birds, reptiles, amphibians, and invertebrates.
In ornithological study, the great horned owl is often compared to the Eurasian eagle-owl (Bubo bubo), a closely related species, which occupies the same ecological niche in Eurasia despite its notably larger size. The great horned owl is also compared to the red-tailed hawk (Buteo jamaicensis), with which it often shares similar habitat, prey, and nesting habits by day; thus the red-tailed hawk is something of a diurnal ecological equivalent. The great horned owl is one of the earliest nesting birds in North America, often laying eggs weeks or even months before other raptorial birds.
Taxonomy
The great horned owl was formally described in 1788 by the German naturalist Johann Friedrich Gmelin in his revised and expanded edition of Carl Linnaeus's Systema Naturae. He placed it with the other owls in the genus Strix and coined the binomial name Strix virginia. Gmelin based his description on that of English naturalist George Edwards who had described and illustrated the great horned owl in 1747 in the second volume of his A Natural History of Uncommon Birds. Edwards had seen a live specimen from Virginia at the house of the Earl of Burlington in Chiswick. Edwards also owned a preserved specimen, and another specimen formed part of the Leverian collection. The great horned owl is now placed in the genus Bubo that was introduced in 1805 by André Duméril. The book bears the date of 1806 on the title page but was actually published in 1805. See:
The great horned owl represents one of the one or two radiations of the genus across the Bering land bridge to the Americas. Whereas the lesser horned owl clearly divided once the owl had spread through the Americas, the consensus seems to be that the snowy owl and the great horned owl divided back in Eurasia and the snowy then spread back over the Arctic through northernmost North America separately from the radiation of the greater and lesser horned owls. One older study suggested that great horned and Eurasian eagle-owls may be conspecific, based on similarities in life history, geographic distribution, and appearance, though this is not supported by genetic evidence, which places them in separate clades of their genus. Genetic testing indicates that the lesser horned owl, and then the snowy owl, not the Eurasian eagle-owl, are the most closely related living species. Pleistocene era fossils have been found of Bubo owls in North America, which may either be distinct species or paleosubspecies, from as far east as Georgia, but predominantly in the Rocky Mountains and to the west of them. Almost all fossils indicate these owls were larger than modern great horned owls.
A large number of subspecies, more than 20 altogether, have been named. However, many of these are not true subspecies and only examples of individual or clinal variation. Subspecies differences are mainly in color and size and generally follow Gloger's and Bergmann's rules: The most conservative treatments of great horned owl subspecies may describe as few as 10, although an intermediate number is typical in most writings.
Fifteen subspecies are currently recognised: B. v. algistus (Oberholser, 1904) – west Alaska B. v. lagophonus (Oberholser, 1904) – central Alaska to northeast Oregon, Idaho and northwest Montana (US) B. v. saturatus Ridgway, 1877 – coastal southeast Alaska to coastal north California (US) B. v. pacificus Cassin, 1854 – coastal central California (US) to northwest Baja California (Mexico) B. v. subarcticus Hoy, PR, 1853 – central west Canada to north Idaho (US) B. v. pallescens Stone, 1897 – southwest US to south Mexico B. v. pinorum Dickerman & Johnson, AB, 2008 – south Idaho to north Arizona and north New Mexico (US) B. v. heterocnemis (Oberholser, 1904) – northeast Canada to the Great Lakes region B. v. virginianus (Gmelin, JF, 1788) – southeast Canada to central, east US B. v. elachistus Brewster, 1902 – south Baja California (Mexico) B. v. mayensis Nelson, 1901 – Yucatán Peninsula (southeast Mexico) B. v. mesembrinus (Oberholser, 1904) – south Mexico to west Panama B. v. nigrescens Berlepsch, 1884 – Colombia to northwest Peru B. v. nacurutu (Vieillot, 1817) – east Colombia through the Guianas to north, east Brazil, Argentina, Bolivia and central Peru B. v. deserti Reiser, 1905 – northeast Brazil (central north Bahia)
In 2026, the American Ornithological Society began considering a proposal to split the great horned owl into as many as four distinct species. The proposal is based on recent data highlighting the distinct behavioral and genetic differences between populations.https://americanornithology.org/wp-content/uploads/2026/05/2026-B.pdf
Description The great horned owl is generally colored for camouflage. The underparts of the species are usually light with some brown horizontal barring; the upper parts and upper wings are generally a mottled brown usually bearing heavy, complex, darker markings. All subspecies are darkly barred to some extent along the sides.
A variable-sized white patch is seen on the throat. The white throat may continue as a streak running down the middle of the breast even when the birds are not displaying, which in particularly pale individuals can widen at the belly into a large white area. South American great horned owls typically have a smaller white throat patch, often unseen unless actively displaying, and rarely display the white area on the chest.
Individual and regional variations in overall color occur, with birds from the subarctic showing a washed-out, light-buff color, while those from the Pacific Coast of North America, Central America, and much of South America can be a dark brownish color overlaid with blackish blotching. The skin of the feet and legs, though almost entirely obscured by feathers, is black. Even tropical great horned owls have feathered legs and feet. The feathers on the feet of the great horned owl are the second-longest known in any owl (after the snowy owl). The bill is dark gunmetal-gray, as are the talons.
All great horned owls have a facial disc. This can be reddish, brown, or gray in color (depending on geographical and racial variation) and is demarked by a dark rim culminating in bold, blackish side brackets. This species' eyebrow-like "horns" are tufts of feathers, called plumicorns. The purpose of plumicorns is not fully understood, but the hypothesis that they serve as a visual cue in territorial and sociosexual interactions with other owls is generally accepted.
Physiology and measurements
The great horned owl is the heaviest extant owl in Central and South America and is the second-heaviest owl in North America, after the closely related but very different-looking snowy owl. It is heavily built, with a barrel-shaped body, a large head, and broad wings. Its size can vary considerably across its range, with populations in interior Alaska and Ontario being largest and populations in California and Texas being smallest, though those from the Yucatán Peninsula and Baja California appear to be even smaller. Adult great horned owls range in length from , with an average of , and possess a wingspan of , with an average of . Females are somewhat larger than males. Mean body weight is for females and for males. Depending on subspecies, maximum weight can reach ..
The wing chord length is . The wing loading, the measured wing area compared to weight, is high, meaning the wings are relatively small in surface area for the bird's weight; the species' wing loading has been described as proportionately the highest among raptors. The tail, being relatively short as is typical of most owls, is long. Like other owl species, the great horned owl is capable of "silent flight", which is the way owls fly while making almost no discernable noise, despite their large size. This is made possible thanks to three main components of the owl's wing structure. The leading edge of their feathers have serrations that help to disrupt the turbulence generated by wing flapping, then the softer feathers help deaden the sound, and finally the trailing fringe of the feathers works to finish cutting the sounds made by flight. The structure of the great horned owl wing also allows it to fly at a very low speed for the size of the species, as slow as 2 miles per hour when they are gliding on breezes.
The legs, feet, and talons are large and powerful. Tarsal length is . The average foot span of a fully spread foot, from talon to talon, is around , as compared to in long-eared owls, in barn owls, and in the great grey owl. Great horned owls can apply at least of crushing power in their talons, a pressure considerably greater than the human hand is capable of exerting. In some big females, the gripping power of the great horned owl may be comparable to much larger raptor species such as the golden eagle.
The hard, inflexible bill of the great horned owl is long, although the culmen, the exposed bill portion as measured along the top of the beak, is only .
The outer ear openings, which are concealed by feathers on the sides of the head, are relatively smaller than those of the Eurasian eagle owl, being in vertical axis, with the left ear slightly larger than the right. Like most exclusively (or near exclusively) nocturnal species, the great horned owl has asymmetrical ear holes that allow for the triangulation of sounds when hunting in the dark. The different-height holes, while still close together, are differentiated enough that the owl is able to use the timing and direction of the sound waves hitting each hole to precisely locate prey even if the prey is located under cover such as snow. The disc-like shape of their faces also helps to direct the sounds they hear toward their ears. While the true nature/purpose of the ear tufts that are present on the great horned owl is unknown, researchers agree that the tufts do not play any role in the hearing ability of the owl. It is estimated that their hearing is up to ten times that of a human being.
The great horned owl's eyes, just slightly smaller than the eyes of a human being, are large even for an owl and rank proportionately among the largest eyes of all terrestrial vertebrates. The great horned owl has cylindrical eyes, which creates more distance from the lens of the eye to the retina, which allows it to act more like a telephoto lens for farther distance sight compared to that possible from round eyes. They are visually highly adapted for nocturnal hunting and provide a wide, almost completely binocular field of view, a large corneal surface, and a predominantly rod retina.
The great horned owl's eye contains both rods and cones, like most species that see in color, but the vision of a great horned owl closely resembles that of many other nocturnal species. The peak wavelengths that are observed by the cones is 555 nm, and the research suggests that the great horned owl has relatively weak color vision, especially compared to other bird species. Despite (or perhaps as a result of) the poorer sense of color vision, the owl manages to have excellent night vision. Instead of turning its eyes, an owl must turn its whole head, and the great horned owl can rotate its neck 270°. The iris is yellow, except in the amber-eyed South American great horned owl (B. v. nacurutu).
Calls