The quintessential storybook owl, the Great Horned Owl is one of the most majestic owl species out there. It is known for its deep hooting vocalization, its intimidating yellow-eyed stare and earlike long tufts.
These tufts give them their name ‘Great Horned’. In this article on Great Horned Owl facts, we are going to learn how it looks like, where it lives, what it eats, and more!
So, let us begin…
Scientific Classification of Great Horned Owl:
|Binomial name||Bubo virginianus|
Great Horned Owl Facts: 1-5
1. The Great Horned Owl, in Central America and South America, is the heaviest known extant owl species. However, in North America, it holds the second position with the heaviest owl being the Snowy Owl.
2. The Great Horned Owl is designed for camouflage. The underpart (including the chest area) of the owl is usually lighter in color with horizontal bearings that are brown in color. The upper wings as well as the upper parts of the bird are usually mottled brown in color and have heavy and dark complex markings.
3. A white patch is often found on the neck that may run down as a streak all the way down to the middle of the breast.
4. The overall color of the Great Horned Owl can vary from region to region. In particular, those in the subarctic region have light-buff and washed out color. Those living in North America’s Pacific Coast, in most of South America and in Central America are known for having dark brownish color with blackish blotching.
5. The skin of the Great Horned Owl is black and so are its feet. The feet are, however, always obscured by the feathers. The feathers on the feet of this species are second-longest among all known owl species.
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6. The talons and the bill of the Great Horned Owl are of dark gunmetal-gray color. The facial disc (which is present in all Great Horned Owls) can vary in color depending on the region. The color ranges from gray to brown to reddish. The facial disc is demarcated by a dark rim that eventually culminates into blacking and bold side brackets.
7. The so-called ‘horns’ of the species are actually tufts of feathers that are technically known as ‘plumicorns’. The functions of the tuft are not yet completely understood by scientists. While scientists actually differ in view about the function of the tufts, they actually agree on the fact that the tufts do not have any role or function in hearing.
8. It is however theorized that these tufts are designed for providing visual cues in both socio-sexual interactions and territorial interactions with other owls.
9. Coming to the physical characteristics, the Great Horned Owl have a barrel-shaped and heavy body build. They have very broad wings and have a large head. It is interesting to note that the size of the species can vary from region to region. For instance, those living in California and Texas are the smallest while those living in Ontario and Alaska are the largest.
10. The average length of the adult Great Horned Owl is 22 inches or 55 centimeters but it can range between 17 inches to 25 inches (43 centimeters to 64 centimeters). The average wingspan of the species is 122 centimeters or 48 inches but it can range anywhere between 91 centimeters to 153 centimeters.
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11. It is interesting to note that the female Great Horned Owls are a bit bigger in size compared to the males. The females have a mean body weight of 3.545 lbs or 1,608 grams. The mean body weight of males is 2.698 lbs or 1,224 grams.
12. The bill of this species is hard and inflexible. The bill measures anywhere between 1.3 inches to 2 inches or 3.3 centimeters to 5.2 centimeters. Interestingly, the exposed portion of the bill (known as the culmen) measures anywhere between 0.83 inches to 1.3 inches or 2.1 centimeters to 3.3 centimeters.
13. Feathers located on the sides of the head are known for covering or concealing the outer ear opening of the Great Horned Owls. It is interesting to note that the right ear of the species is slightly smaller than the left ear.
14. The eyes of the Great Horned Owl are really big but are slightly smaller than that of humans. The owls are not capable of turning their eyes. In order to look in other direction, they need to turn their heads. They are capable of rotating their neck up to 270°. The iris of the eyes are always yellow except for South American Great Horned Owl which is known to have amber-colored iris.
15. Did you know that the Great Horned Owls have really long necks though it doesn’t appear to be so? They have 14 cervical vertebrae (humans have only 7). They keep their neck squished into an ‘S’ shape, which remains covered with their fluffy neck feathers, which explains why it appears that they don’t have long necks.
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16. The range of the Great Horned Owl is quite diverse. It can be found from all the way up in subarctic North America to the rest of North America down to Central America and all the way down to South America to the upland regions of Argentina, Peru and Bolivia.
That’s where their range ends. From the point where the range of Great Horned Owl ends in South America, the range of Magellanic Horned Owl begins and continues all the way down to the tip of South America.
17. When it comes to habitat, the Great Horned Owl is not really a picky type. It can take shelter just about anywhere from treetops to open areas to even parks where humans are abundant.
18. Barns, Churches, building tops, deserted buildings, croplands, pastures, wetlands, fields and even rainforests etc. all are part of their habitat. They can even be found in cities!
19. It is interesting to note that they don’t really prefer to be in Amazon Rainforest. They can, however, take residence in trees bordering mixed forests, coniferous forests, deciduous forests, tropical rainforests, prairie, pampas, deserts, mountainous areas, rocky coasts, subarctic tundra, mangrove swamp forests and urban areas.
20. They prefer not to be around humans but quick loss of habitat and environmental changes often force them to be in areas close to human habitat. This habitat loss is also gradually thinning out their population from various areas.
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21. Great Horned Owls are known for eating way more food compared to other owl species. They are usually nocturnal hunters and their peak hunting time is between 8:30 PM to 12:00 AM. The hunting time can again pick up between 4:30 AM and sunrise.
22. Their eyes are highly adapted to nocturnal hunting as they have a wide and almost binocular point of view. They have predominantly rod retina and large corneal surface, allowing them to have excellent view during the night.
23. At night, they can spend a lot of time searching for prey. They are usually very patient and will wait for the prey to come out in the open. Though the Great Horned Owl is usually a nocturnal hunter, it is also known to hunt in broad daylight.
24. Their hunting style is quite raptor-like as they are raptors. They will spot their prey from a high position and then pursue the prey over meadows, woodland edges, wetlands, open waters and various other habitats.
25. When hunting for very small prey, the owls are known for walking on ground simply for stalking the prey around various obstacles and bushes.
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26. Their diet is really diverse and these birds are not at all shy of adapting to various diets. They mostly eat birds and mammals.
27. They are very formidable hunters and can take on and kill prey that’s bigger than their own size. However, unlike in case of small prey that they can swallow whole, they tear off the large prey into small bits using their powerful talons and then consume.
28. Their talons are extremely powerful and they sever the spine of large prey using their powerful grip to instantly paralyze the victim.
29. They mostly eat tiny rodents, scorpions, mice, hares, geese, raptors, American Coots and rabbits. However, they are also known to feed on bats, skunks, prairie dogs, marmots, woodchucks, squirrels, crows, hawks, doves, ravens, starlings, rails, grebes, mergansers, loons, ducks, porcupines, gophers, rats, shrews, moles, voles, etc.
30. They are also eating insects, reptiles, invertebrates, fish and sometimes, carrion. They live only and only on a non-vegetarian diet. They are strictly carnivores.
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31. These amazing birds of prey are known for nesting on several types of trees such as pine, beech, juniper, cottonwood etc. During breeding seasons, the nests are known to deteriorate in condition and they are rarely used in later years.
32. Their usual habit is to adopt a nest that some other species had built and then discarded. They may however choose to nest in deserted building, dead snags, cavities in live trees, human-made platforms and even cliff ledges.
33. It is not unusual to see the Great Horned Owl nest on ground. They occasionally do that. It is a known fact that the pairs will first roost together close to the nesting site continuously for several months before the female eventually lays egg.
34. The size of the nest and the material used for making the nest can vary differently among the Great Horned Owls. This difference comes from the fact that the nests are usually built by some other species such as crows, ravens, squirrels, herons, red-tailed hawks, other hawk species etc.
35. Some Great Horned Owls may choose to line their nests with a variety of things like downy feathers that they pluck from their own breasts, leaves, bark shreds, trampled pellets, feathers or fur from the prey that they kill etc.
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36. Great Horned Owls are monogamous by nature. They will mate with same partner year after year despite the fact that they are very solitary creatures. They will recognize their partners during the mating seasons through calls.
37. If one of the partners dies or is removed from its natural habitat, the one that is left behind needs to find a new partner. This might take several years to happen.
38. During the breeding season they will be start with calls and courtship. The courtship usually starts in October and ends in December and for those that need to find a partner, the choosing of the mate takes place between December and January.
39. During courtship, the males emphatically hoot and lean over. At the same time, they also puff up their white throats and resemble a ball. The display of the white throats work as a visual stimuli in low light conditions. Yes, the courtship takes place in low light conditions.
40. During courtship, the male is known for flying up and down a perch and approaches a potential mate. The male will then try to rub his bill against the potential female. If the female is receptive, she will hoot but will ensure that her hooting is subdued in comparison to the male.
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41. The male may also try to convince a female by gifting her a freshly caught prey. The receptive female may then share the prey with the male.
42. It has been observed by scientists that during the breeding season, the males continue to hoot emphatically for up to 6 weeks towards the end of a year. The females will hoot but for a shorter period of time usually lasting no more than 10 days.
43. Being strictly monogamous, the same pair may continue to mate year after year and even for life except for scenarios of death or being removed from natural habitat.
44. The pair that have already mated once will usually go for a milder courtship only to rekindle their association and improve their bonding before they start reproducing. After the young owls are born and become independent, the pair will not usually stay together and maintain a solitary lifestyle.
45. It is the duty of the male to find a nest. The male will first find a nest and fly to it and then repeatedly stomp on it to get the attention of the female. They usually prefer large nests with open access rather than going for the ones that are enclosed by branches. This choice is pretty obvious because the Great Horned Owls are pretty big birds.
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46. The time when the eggs are laid by the female Great Horned Owls vary from region to region. For instance, the females will lay eggs anywhere between late November and early January in southern Florida. Those that live in the region Texas to Georgia will lay eggs between late December to early February.
47. Similarly, the egg laying months may be between early February to late March or late February to early April or early March to late April.
48. The usual clutch size is 2 eggs but the clutch size can vary between 1 and 6 eggs. The number of eggs laid will depend on the environmental conditions. The eggs have an average width of 1.83 inches and have an average length of 2.2 inches. The average weight of the eggs is 51 grams.
49. The Great Horned Owls have an incubation period of 33 days on average but it can range anywhere between 28 days and 37 days. Mostly females are responsible for incubation while the males are responsible for hunting and bringing food to females. The males deliver the first round of dinner typically after sunset (that is, as soon as it gets dark).
50. The average age of the newborns is 34.7 grams. During the first four weeks of their lives, the newborns gain weight at a rate of 33.3 grams a day on an average. By the time they reach 25 to 29 days old, the males will be around 800 grams and the females will be around 1,000 grams.
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51. The newborns, that is the nestling owls, develop in behavior anywhere between 2 weeks and 2 months after birth. Within this time, they learn to defend themselves. They learn to climb and to grasp food.
52. The young owls develop the ability of vocalization even before they hatch out of the eggs. When inside the egg, they will usually exert weak chirps. Shortly after hatching, they will develop a raspy chirp. As they keep growing, the character, pitch and intensity of their calls increase very rapidly.
53. The young owls manage to move out of the nest and get on to nearby branches by the time they are six weeks old. At around 7th week they develop the ability to fly. They usually do not become very competent in flying until they attain the age of 10 to 12 weeks.
54. The young ones will eventually leave the nest, but the timing will depend on abundance of food. Once they leave their nests, they usually stay within 13.1 to 52 hectares from the nest. They stay within this range into the fall. By end of fall, they will disperse to several thousand hectares.
55. It has been observed that the young ones that leave their nests often beg for food from their parents up to 5 months after leaving the nest. Some young ones will not leave the territory of their parents completely until their parents start reproducing again. The young ones reach sexual maturity by the time they are 2 years old.
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56. Great Horned Owls are known for roosting in human-made structures, ledges, cavities, thick brush, snags and trees.
57. They are nocturnal. They will go out hunting during the night. However, when the food is scarce, they will go out hunting during the evening and continue to hunt till early morning. During the winter months when the food becomes really scarce, they will not shy away from hunting during broad daylight.
58. They are extremely ferocious when it comes to defending their territories and when it comes to protecting their eggs or young ones. They will also defend the young ones after they leave their nests.
59. When it comes to protecting their territories, eggs or young ones, they will clap their bills, scream, make guttural noises, hiss and then spread out their wings to warn. If the situation escalates, they will strike with their strong talons. They are also known to kill members of their own species.
60. They vocalize when its is dark after the sunset or during early morning. They make the very popular Hoo H’hoo sound.
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61. This bird is not known to have natural predators at least when they have grown into adults. However, the young ones may be hunted by Hawks.
62. It is a known fact that more than 50% of the young Great Horned Owls are hunted and eaten by hawks before they can reach adulthood.
64. After these, humans are a threat to these owls. Humans can simply kill these birds or accidentally poison them. It is not unusual that rats and rodents are often poisoned by humans. These poisoned rodents can become prey of these owls and the toxins in the bodies of their prey can spread in their bodies and kill them.
65. IUCN has listed the Great Horned Owls as ‘Least Concern’ for now. With around 5.3 million wild horned owls (including Magellanic species) in the Americas, these birds are quite abundant.