The Great Horned Owl (Bubo virginianus) is one of the most widespread birds in North America. They are the largest owl species that bird watchers are likely to encounter across most of the continent.
These powerful nocturnal hunters occur in most habitats and have adapted well to human-altered environments like farmland, suburban, and even urban environments. So just how big are Great Horned Owls?
Great Horned Owls are probably the second largest owls in the United States. They are slightly smaller than the Snowy Owl and slightly larger than the Great Gray Owl. Great Horned Owls can measure over 2 ft (60cm) in length and can weigh up to 5.5 lb (2.5kg).
Female Great Horned Owls are significantly larger than males, a trait that is common in owls and other birds of prey. Females also have a larger wingspan than males, although the difference is less pronounced than their weight.
There are at least 15 subspecies of Great Horned Owls, and each occurs in different geographical areas. Across their wide distribution range, the biggest Great Horned Owls in North America occur in Alaska and the far northeast.
They become progressively smaller from north to south, with the smallest individuals occurring in Mexico. This interesting relationship between body size and latitude can be seen in many birds and is thought to be an adaptation to colder climates.
Read along to learn more about the size of Great Horned Owls, one of America’s most iconic birds.
Great Horned Owls are the second largest owl in the US
The Great Horned Owl has a wingspan of between 39.8 and 57.1 in (101-145 cm). The large variation is due to the marked sexual dimorphism of the species and the variation in size between the various subspecies.
Great Horned Owls do not have particularly long wings but they are capable of fairly high-speed flight of up to 40 miles per hour or so.
The leading and trailing edges of their broad wings are lined with finely textured feathers. These feathers dampen the sound of wind rushing over the wings, which allows these nocturnal hunters to swoop in undetected.
The large wingspan of a Great Horned Owl
Great Horned Owls are large, bulky owls. On average, the females of each subspecies are significantly heavier than the males.
Great Horned Owls are far lighter than they appear, with an average weight of about 3.5 lb (1.5 kg). Their long legs and bulky feathers create the appearance of a large, barrel-shaped bird of about 2 ft (60 cm) long from tail to bill. Their length is comparable to the knee height of an average person or an infant of 3 months old or so.
Great Horned Owls are just a fraction of our size but they have remarkably large eyes. In fact, their eyes are similar in size to human eyes. These owls use their huge, light-sensitive eyes to help them detect prey in low-light conditions.
Great Horned Owls also have large feet with long talons. Their feet can measure a whopping 8 in (20 cm) or so from talon tip to talon tip when fully extended. This is comparable to an adult human hand.
These owls use their large feet and razor-sharp talons to grasp and kill their prey with a powerful grip strength of about 28lbs (13 kg). Not bad for a bird that only weighs 2-5 pounds!
Close up of a perched Great Horned Owl, also known as the Hoot Owl
The biggest Great Horned Owl on record was a female that weighed 5.5 lb (2503 g). This specimen was of the northeastern subspecies, B. v. virginianus.
There is little concrete evidence for just how much a Great Horned Owl is able to lift. They have been reported to be able to lift prey several times their own body weight, however.
Great Horned Owls are able to kill animals that are much larger than themselves, but they will feed on the ground when their prey is too large to carry away.
The heaviest prey they can carry for any distance is likely to be about half of their own body weight or about 1 to 2lbs.
Great Horned Owl in flight, with full spread wings
Great Horned Owls are members of the Bubo genus, a group of 18 large owl species that live on every continent except Antarctica and Australia. These owls take over the role of large birds of prey like hawks and eagles when the sun sets.
The Great Horned Owl's size allows it to feed on a wide variety of prey. In fact, these birds target the largest variety of any North American owl species. They regularly hunt animals up to the size of hares and large waterfowl, and the ability to kill such large prey requires large talons and the size and strength to use them efficiently.
Great Horned Owls do not pass up on small prey items, however. They will happily feed on prey as small as insects. Having such a wide variety of prey animals available to them is undoubtedly part of their great success and has allowed them to adapt to so many habitats from Alaska in the far north to the southern tip of South America.
Perched Great Horned Owl in its natural habitat in the forest of Southwest Washington State
The Great Horned Owl is one of the largest owl species in the United States, but how do they stack up to other birds in America and the rest of the world? Continue reading to find out.
The Great Horned Owl is similar in size to two other North American owls. They are about the same length as the Snowy Owl but slightly lighter in weight. Great Horned owls are significantly heavier than the next largest species, the Great Gray Owl, although they have a slightly shorter body length than that species.
It is fair to say that the Great Horned Owl is one of the largest owl species in the world, although some species grow even bigger. The similar-looking Eurasian Eagle-Owl and the Blakiston's Fish Owl of East Asia grow to impressive weights of up to 10lbs (4.6 kg).
Great Horned Owls are similar in size to the Red-Tailed Hawk, a common and widespread North American bird of prey. These two birds are thought to occupy similar ecological niches, separated by the time of day that they are active.
Close up portrait of a Great Horned Owl
Great Horned Owls are not technically eagles, although owls of their genus are often called eagle-owls in other parts of the world. Great Horned Owls are the second largest owls in North America by weight and the third largest by length.
Great Horned Owls are very large birds but they are far too small to pick up a human. At just 3.5 lb (1.5 kg) or so, they are unlikely to be able to pick up a human baby.
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